Synthesis of the zinc complexes, 2a-c S-3

General remarks S-1

Synthesis of zinc bromide S-2

Synthesis of eugenol epoxide, 3n S-2

Synthesis of the zinc complexes, 2a-c S-3

General catalytic procedures S-9

Procedure for the catalyst recovery S-11

Procedure for the isolation of the pure cyclic carbonates S-12 Optimization of the catalytic system: Table S1, Figure S1 S-13 Optimization of the reaction condition: Tables S2-S5, Figures S2-S4 S-14

Catalyst reutilisation: Table S6 S-18

Reaction scope: Table S7 S-19

NMR of cyclic carbonates S-20

Analytical data for 4n:

H and

C NMR, elemental analysis and MS(ESI) S-27

Crystal structure determination S-28

Crystallographic Tables for 2a: Tables S8-11 S-29

Crystallographic Tables for 2b: Tables S12-15 S-34

Bibliography S-41

1

General remarks

All the reactions that involved the use of reagents sensitive to oxygen or to moisture were carried out under an inert atmosphere employing standard Schlenk techniques. All chemicals and solvents were commercially available and used as received except where specified. NMR spectra were recorded at room temperature either on a Bruker Avance 300-DRX, operating at 300 MHz for ¹H, at 75 MHz for ¹³C or on a Bruker Avance 400-DRX spectrometers, operating at 400 MHz for ¹H and at 100 MHz for ¹³C. Chemical shifts (δ) are expressed in ppm and they are reported relative to TMS. The coupling constants (J) are expressed in hertz (Hz). The ¹H NMR signals of the compounds described in the following were attributed by 2D NMR techniques.

Assignments of the resonances in ¹³C NMR were made by using the APT pulse sequence, HSQC and HMBC techniques.

Catalytic tests were analysed by ¹H NMR spectroscopy: the reaction crude was diluted in chloroform and analysed by ¹H NMR, after the addition of an internal standard (ISTD).

Low resolution MS spectra were recorded with instruments equipped with ESI/ion trap sources. The values are expressed as mass−charge ratio and the relative intensities of the most significant peaks are shown in brackets.

Elemental analyses were recorded in the analytical laboratories of Università degli Studi di Milano.

X-ray data collection for the crystal structure determination was carried out by using Bruker Smart APEX II CCD diffractometer with the Mo K radiation ( = 0.71073) at 296 K.

2,6-bis(methanesulfonyloximethyl)pyridine^[1] tri-tosyl PcL macrocycle^[2] and ligand 1^[2] were synthetized as previously reported in literature.

2

Synthesis of zinc bromide

A solution of HBr (30%) (3.0 mL) was added dropwise to a suspension of ZnO (0.4880 g, 6.0 mmol) in water;

during the addition, the suspension became a solution. Then the reaction mixture was left to react under stirring at 50 °C for 4 hours.

The solvent was evaporated under vacuum, the solid was rinsed with toluene, collected by filtration and then it was rinsed again with toluene. Finally, the residual solvent was evaporated under reduced pressure.

The product is collected as white powder, highly hygroscopic.

Yield: 99%

Synthesis of eugenol epoxide, 3n

A solution of m-CPBA (80%) (1.7257 g, 10 mmol) was added dropwise to a solution of eugenol (0.8211 g, 5 mmol) in chloroform (25.0 mL) in 15 minutes at 0 °C under stirring. The mixture was left to react under nitrogen at room temperature for 2 hours.

The reaction mixture was washed with a saturated aqueous solution of NaHCO3 (10 mL x 3). and H2O (10 mL x 3). The reunited organic phases were treated with Na2SO4, filtered and finally the solvent was evaporated under vacuum at room temperature.

The crude was purified via flash chromatography over silica gel, using hexane and diethyl ether as eluent (9:2). The product was isolated as a brownish oil.

Yield: 60%

NMR (¹H): in CDCl3 δ 6.88 (d, J = 8.0 Hz, 1H, H9), 6.78 (s, 1H, H4), 6.75 (d, J = 1.5 Hz, 1H, H10), 5.58 (s, 1H, H8), 3.91 (s, 3H, H6), 3.24 – 2.99 (m, 1H, H2),

2.82 (dd, J = 8.2, 3.3 Hz, 3H, H1 overlapped with H3), 2.56 (dd, J = 4.9, 2.7 Hz, 1H, H1’)

Spectral data are consistent with literature values.^[4]

3

Synthesis of the zinc complexes, 2a-c

Synthesis of complexes 2a, 2b, 2c

A zinc (II) salt (0.65 mmol) was slowly added to a solution of ligand 1 (0.1340 g, 0.75 mmol) in DCM (20.0 mL).

The mixture was left to react at room temperature for 1.5 hours.

The reaction mixture was then filtered over a Büchner and washed with DCM (5.0 mL x 2), with cold MeOH (few drops), and again with DCM (5.0 mL). The product was recovered as a white powder and it was dried under vacuum.

Single crystals suitable for XRD were obtained by slow evaporation of a water solution of the complex.

Yields: 2a 80% (0.2040 g) [zinc source: ZnCl2 anhydrous]

MS (ESI) m/z (%) = calcd. for C11H18Cl2N4Zn: 340.02, found: 305 (100) [M⁺-1Cl]

Elem. An. C11H18Cl2N4Zn∙2H2O Calcd: C 34.90%, H 5.86%, N 14.80; found: C 34.60%, H 5.59%, N 14.49%

NMR (¹H) in d6-DMSO: δ 8.11 (t, J = 7.7 Hz, 1H, Hj), 7.52 (d, J = 7.7 Hz, 2H, Hi), 4.86 (m, 1H, H6), 4.68 (m, 2H, H3,9),

4.37 (dd, J = 17.6, 6.7 Hz, 2H, H2,10’), 3.90 (d, J = 17.6 Hz, 2H, H10,2’), 2.90 (m, 2H, CH2), 2.74 (m, 2H, CH2), 2.38 (m, 2H, CH2), 2.18 (m, 2H, CH2).

NMR (¹³C) in d6-DMSO δ 155.6 (C1,11), 141.7 (Ci), 122.4 (Cj), 51.6 (C2,10), 47.7 (C4,8), 46.2 (C5,7)

4 Complex 2a: ¹H NMR (400 MHz, d6-DMSO)

Complex 2a: ¹³C NMR (100 MHz, d6-DMSO)

5 Yields: 2b 90% (0.2888 g) [zinc source: ZnBr2]

MS (ESI) m/z (%) = calcd for C11H18Br2N4Zn: 427,92, found: 351 (100), [M⁺-1Br]

Elem. An. C11H18Br2N4Zn∙2 H2O Calcd: C 28.26%, H 4.74%, N 11.98%; found: C 28.51%, H 4.30%, N 11.84%

NMR (¹H) in d6-DMSO: δ 8.11 (t, J = 7.7 Hz, 1H, Hj), 7.53 (d, J = 7.7 Hz, 2H, Hi), 4.82 (m, 1H, H6), 4.67 (m, 2H, H3,9),

4.36 (dd, J = 17.6, 6.7 Hz, 2H, H2,10’), 3.91 (d, J = 17.6 Hz, 2H, H10,2’), 2.91 (m, 2H, CH2), 2.75 (m, 2H, CH2), 2.39 (m, 2H, CH2), 2.17 (m, 2H, CH2) NMR (¹³C) in d6-DMSO δ 155.7 (C1,11), 141.9 (Ci), 122.5 (Cj), 51.5 (C2,10), 47.8 (C4,8),

46.2 (C5,7)

6 Complex 2b: ¹H NMR (400 MHz, d6-DMSO)

Complex 2b: ¹³C NMR (100 MHz, d6-DMSO)

7

Yields: 2c 91% (0.3576 g) [zinc source: ZnI² anhydrous]

MS (ESI) m/z (%) = calcd for C11H18I2N4Zn: 523,89, found: 397 (100) [M⁺-1I]

Elem. An. C11H18Br2N4Zn∙2 H2O Calcd: C 25.14%, H 3.45%, N 10.66%; found: C 25.43%, H 3.28%, N, 10.28%

NMR (

H)

4.25 (m, 1H, H6), 3.87 (d, J = 17.6 Hz, 2H, H10,2’), 2.87 (m, 2H, CH2), 2.77 (m, 2H, CH2), 2.50 (m, 2H, CH2) overlapping with DMSO, 1.81 (m, 2H, CH2)

NMR (

C) in

8 Complex 2c: ¹H NMR (400 MHz, d6-DMSO)

Complex 2c: ¹³C NMR (400 MHz, d6-DMSO)

9

General catalytic procedures

General catalytic procedure: Method A

In a 2.5 mL glass liner equipped with a screw cap and glass wool, the catalyst (see Tables S1-S7) and the epoxide (250 µL) were added. The vessel was transferred into a 250 mL stainless-steel autoclave; three vacuum-nitrogen cycles were performed and CO2 was charged at room temperature (0.2 or 0.4 or 0.8 MPa).

The autoclave was placed in a preheated oil bath (at 75 or 100 or 125 °C) and it was left to react under stirring (for 2 to 4 hours), then it was cooled at room temperature in an ice bath and slowly vented. The crude was treated with chloroform (700 µL) and a sample (150 µL) was analysed by ¹H NMR spectroscopy by using 1,3,5- trimethylbenzene (0.11 eq.) as the internal standard.

General catalytic procedure: Method B

In a 2.5 mL glass liner equipped with a screw cap and glass wool, the catalyst (2b) (0.5 mol%) and the epoxide (250 µL) were added and they were suspended in propylene carbonate (125 µL) as the solvent. The vessel was transferred into a 250 mL stainless-steel autoclave; three vacuum-nitrogen cycles were performed and CO2 was charged at room temperature (0.8 MPa). The autoclave was placed in a preheated oil bath (at 125

°C) and left react under stirring (for 3 hours), then it was cooled at room temperature in an ice bath and it was slowly vented. The crude was treated with chloroform (700 µL) and a sample (150 µL) was analysed by

1H NMR spectroscopy by using 1,3,5-trimethylbenzene (0.11 eq.) as the internal standard.

General catalytic procedure: Method C

In a 2.5 mL glass liner equipped with a screw cap and glass wool, the catalyst (2b) (0.5 mol%) mol dissolved in dimethyl sulfoxide (250 µL) and the styrene oxide (3a) (250 µL, 2.19 mmol) were added. The vessel was transferred into a 250 mL stainless-steel autoclave; three vacuum-nitrogen cycles were performed and CO2

was charged at room temperature (0.8 MPa). The autoclave was placed in a preheated oil bath (at 75 or 100 or 125 °C) and left react under stirring (for 4 hours), then it was cooled at room temperature in an ice bath and it was slowly vented. The crude was treated with chloroform (700 µL) and a sample (150 µL) was analysed by ¹H NMR spectroscopy by using 1,3,5-trimethylbenzene (0.11 eq.) as the internal standard.

10 Catalyst recycle

Three 2.5 mL glass liners equipped with screw caps and glass wool were filled with the catalyst (2b) (0.5 mol%) and the styrene oxide (3a) (250 µL, 2.19 mmol). The vessels were transferred into a 250 mL stainless- steel autoclave; three vacuum-nitrogen cycles were performed, and CO2 was charged at room temperature (0.8 MPa). The autoclave was placed in a preheated oil bath (125 °C) and it was left to react under stirring (for 3 hours), then it was cooled at room temperature in an ice bath and slowly vented. The reaction mixture in the first vessel was treated with chloroform (700 µL), and a sample (150 µL) was analysed by ¹H NMR spectroscopy by using 1,3,5-trimethylbenzene (0.11 eq.) as the internal standard. New styrene oxide (3a) (250 µL, 2.19 mmol) was added to the remaining 2 vessels. The autoclave was charged again with CO2 and left to react in the exactly same conditions for additional 3 h.

At the end of the second run, the reaction mixture in the second vessel was treated with chloroform (700 µL), and a sample (150 µL) was analysed by ¹H NMR spectroscopy by using 1,3,5-trimethylbenzene (0.11 eq.) as the internal standard. New styrene oxide (3a) (250 µL, 2.19 mmol) was added to the reaction mixture into the third vessel. The autoclave was charged again with CO2 and left to react in the exactly same conditions for additional 3 h.

At the end of the third run, new styrene oxide (3a) (250 µL, 2.19 mmol) was added to the reaction mixture into the third vessel again, then the autoclave was charged again with CO2 and left to react in the exactly same conditions for additional 3 h.

At the end of the last cycle of reaction, the crude was treated with chloroform (700 µL). A sample (150 µL) was analysed by ¹H NMR spectroscopy by using 1,3,5-trimethylbenzene (0.11 eq.) as the internal standard.

11

Procedure for the catalyst recovery

In a 3 mL glass liner equipped with a screw cap and glass wool, the catalyst (2b) (0.050 g, 0.5 mol%) and the styrene oxide (3a) (2,5 mL, 21.9 mmol) were added. The vessel was transferred into a 250 mL stainless-steel autoclave; three vacuum-nitrogen cycles were performed, and CO2 was charged at room temperature (0.8 MPa). The autoclave was placed in a preheated oil bath (125 °C) and it was left to react under stirring (for 3 hours), then it was cooled at room temperature in an ice bath and slowly vented. The crude was treated with chloroform (4.0 mL) to precipitate the catalyst. The mixture was filtered and washed with chloroform (2.0 mL). A sample (200 µL) of the reaction solution was analysed by ¹H NMR spectroscopy by using 1,3,5- trimethylbenzene (0.11 eq.) as the internal standard.

The recovered catalyst (0.038 g) was analysed by elemental analysis and by ¹H NMR spectroscopy. The analyses showed no traces of catalyst degradation; however, the elemental analysis showed a slightly higher content of carbon and lower nitrogen than expected.

Elem. An. C11H18Br2N4Zn∙2 H2O Calcd: C 28.26%, H 4.74%, N 11.98%; found: C 29.54%, H 3.87%, N 8.67%

1H NMR (400 MHz, in d6-DMSO) δ 8.10 (t, J = 7.7 Hz, 1H), 7.52 (d, 2H), 4.79 – 4.75 (m, 1H), 4.69 – 4.65 (m, 2H), 4.38 (d, J = 6.8 Hz, 1H), 4.34 (d, J = 6.7 Hz, 1H), 3.92 (s, 1H), 3.88 (s, 1H), 2.97 – 2.83 (m, 2H), 2.78 – 2.73 (m, 2H), 2.46 – 2.35 (m, 2H),

2.15 – 2.11 (m, 2H)

Catalytic results:

Conversion 86%

Selectivity >99%

12

Procedure for the isolation of the pure cyclic carbonates

For styrene carbonate (3a) at the end of the reaction, after venting the autoclave, 700 µL of DCM were added and the reaction mixture was filtered and concentrated under vacuum. N-hexane (30 mL) was added, and the mixture was stored at 4 °C until the precipitation of the product as a white powder that was filtered over a Büchner and dried under reduced pressure.

For the other carbonates, after venting the autoclave, 700 µL of DCM were added to precipitate the catalyst, the reaction mixture was filtered, and DCM was evaporated under reduced pressure. After that, if necessary when conversion and selectivity were not quantitative, the product was purified via flash chromatography on silica (see the section NMR of cyclic carbonates for the eluent). The products were obtained as brownish oils.

13

Optimization of the catalytic system: Table S1, Figure S1

ENTRY CATALYST SELECTIVITY (%)^[b] CONVERSION (%)^[b] TOF (h^-1)^[c] TON^[d]

1 2a (1%) - TBAC (2%) 95 90 11 45

2 TBAC (2%) 99 97 12 48,5

3 TBAC (1%) 97 70 17.5 70

4 2a 92 78 19,5 78

5 ZnCl2 (1%) - 22 5.5 22

6 2b (1%) - TBAB (2%) >99 >99 12 49,5

7 TBAB (2%) 91 99 12 49,5

8 TBAB (1%) 96 60 15 60

9 2b (1%) >99 >99 25 >99

10 ZnBr2 (1%) - 99 25 99

11 2c (1%) - TBAI (2%) 93 96 12 48

12 TBAI (2%) 99 95 12 47,5

13 TBAI (1%) 99 52 13 52

14 2c (1%) 97 99 25 99

15 1 (1%) - 5 - -

[a] Reactions conditions: neat, 250 µL of 3a (2.19 mmol), [Zn] = 1%, TBAX = 2%, at 125 °C; P(CO2) = 0.8 MPa; reaction time = 4 h. [b]

Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard (see General Catalytic Procedures: Method A). [c] Turnover frequency (mol3a∙molcat-1∙reaction time^-1). [d] Turnover number (mol3a∙molcat-1).

Figure S1: Screening of the [Zn(II)(X)(Pc-L)]X, 2a-c, catalysed cycloaddition of CO2 to styrene epoxide^[a]

[a] Reactions conditions: neat, 250 µL of 3a (2.19 mmol), [Zn] = 1%, TBAX = 2%, at 125 °C; P(CO2) = 0.8 MPa; reaction time = 4h.

14

Optimization of the reaction conditions: Table S2-S5, Figure S2-S4

Table S2: catalytic test for different catalyst loading

ENTRY CATALYST LOADING SELECTIVITY (%)^[b] CONVERSION (%)^[b] TOF (h^-1]^[c] TON^[d]

1 2b 1 >99 >99 >33 >99

2 2b 0.5 >99 >99 67 200

3 2b 0.1 >99 53 177 530

4 2b 0.01 >99 2 667 200

5 2c 1 95 >99 >33 >99

6 2c 0.5 95 >99 67 200

7 2c 0.1 94 83 277 830

[a] Reactions conditions: neat, 250 µL of 3a (2.19 mmol), at 125 °C; P(CO2) = 0.8 MPa; reaction time = 3 h. [b] Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard (see General Catalytic Procedures: Method A).

[c] Turnover frequency (mol3a∙molcat-1∙reaction time^-1). [d] Turnover number (mol3a∙molcat-1).

Figure S1: conversion and selectivity of complex 2b and complex 2c as the catalyst

[a] Reactions conditions: neat, 250 µL of 3a (2.19 mmol), at 125 °C; P(CO2) = 0.8 MPa; reaction time = 3 h. [b] Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard (see General Catalytic Procedures: Method A).

0 10 20 30 40 50 60 70 80 90 100

0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9 1

Catalyst loading (mol%)

Conversion 2b

Selectivity 2b

Conversion 2c

Selectivity 2c

15 Table S3: catalytic test for temperature optimization

ENTRY CATALYST T (°C) SELECTIVITY (%)^[b] CONVERSION (%)^[b] TOF (h^-1]^[c] TON^[d]

1 2b 100 61 30 15 60

2 2b 75 10 10 5 20

3 2b^[e] 100 97 58 29 116

4 2b^[e] 75 82 39 19,5 78

5 2c 100 93 84 42 168

6 2c 75 42 12 12 24

[a] Reactions conditions: neat, 250 µL of 3a (2.19 mmol), 2b = 0.5% or 2c = 0.5%, P(CO2) = 0.8 MPa; reaction time = 4 h. [b]

Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard (see General Catalytic Procedures: Method A). [c] Turnover frequency (mol3a∙molcat-1∙reaction time^-1). [d] Turnover number (mol3a∙molcat-1). [e] The

catalyst is previously dissolved in 250 µL of dimethyl sulfoxide (see General Catalytic Procedures: Method C)

16 Table S4: catalytic test for time optimization

ENTRY CATALYST TIME (h) SELECTIVITY (%)^[b] CONVERSION (%)^[b] TOF (h^-1]^[c] TON^[d]

1 2b 1 >99 22 22 22

2 2b 2 >99 86 43 86

3 2b 2.5 >99 94 38 94

4 2b 3 >99 99 33 99

5 2b 4 >99 >99 25 >99

6 TBAB 1 99 40 20 20

7 TBAB 2 96 75 18 35,5

8 TBAB 2.5 95 86 16 41

9 TBAB 3 96 86 14 41,5

10 TBAB 4 94 99 12 47

[a] Reactions conditions: neat, 250 µL of 3a (2.19 mmol), 2b = 1%, TBAB = 2%, at 125 °C; P(CO2) = 0.8 MPa. [b] Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard (see General Catalytic Procedures: Method A).

[c] Turnover frequency (mol3a∙molcat-1∙reaction time^-1). [d] Turnover number (mol3a∙molcat-1).

Figure S3: conversion and selectivity in dependence on reaction time

[a] Reactions conditions: neat, 250 µL of 3a (2.19 mmol), 2b = 1%, TBAB = 2%, at 125 °C; P(CO2) = 0.8 MPa. [b] Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard (see General Catalytic Procedures: Method A).

0 10 20 30 40 50 60 70 80 90 100

0 1 2 2,5 3 4

Reaction time (h)

Conversion 2b Selectivity 2b Conversion TBAB Selectivity TBAB

17 Table S5: catalytic test for CO2 pressure optimization

ENTRY CATALYST pCO2 (MPa) SELECTIVITY (%)^[b] CONVERSION (%)^[b] TOF (h^-1]^[c] TON^[d]

1 2b 0.8 >99 >99 25 >99

2 2b 0.4 >99 89 22 89

3 2b 0.2 79 53 13 53

4 2b 0.1 77 31 8 31

[a] Reactions conditions: neat, 250 µL of 3a (2.19 mmol), 2b = 1%, at 125 °C; reaction time = 4 h. [b] Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard (see General Catalytic Procedures: Method A). [c]

Turnover frequency (mol3a∙molcat-1∙reaction time^-1). [d] Turnover number (mol3a∙molcat-1).

Figure S4: conversion and selectivity in dependence of CO2 pressure

[a] Reactions conditions: neat, 250 µL of 3a (2.19 mmol), 2b = 1%, at 125 °C; reaction time = 4 h. [b] Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard see General Catalytic Procedures: Method A).

0 10 20 30 40 50 60 70 80 90 100

0,1 0,2 0,3 0,4 0,5 0,6 0,7 0,8 0,9

Carbon dioxide pressure (MPa)

Conversion Selectivity

18

Table S6: catalyst recycle

Table S6: catalyst recycle

ENTRY CATALYST RUN SELECTIVITY (%)^[b] CONVERSION (%)^[b] TOF (h^-1]^[c] TON^[d]

1 2b 1^st >99 99 66 200

2 2b 2^nd >99 95 63 390

3 2b 4^th >99 88 59 756

[a] Reactions conditions: neat, 5 mL of 3a (43.78 mmol), 2b = 0.5%, at 125 °C; P(CO2) = 0.8 MPa; reaction time = 3 h. [b] Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard (see Catalyst recycle). [c] Turnover

frequency (mol3a∙molcat-1∙reaction time^-1). [d] Turnover number (mol3a∙molcat-1).

19

Table S7: reaction scope

Table S7: Substrate scope of the [Zn(II)(Br)(Pc-L)]Br, 2b, catalysed cycloaddition of CO2 to epoxides ENTRY CATALYST SUBSTRATE SELECTIVITY (%)^[b] CONVERSION (%)^[b] TOF

(h^-1]^[c] TON^[d]

1 2b epichlorohydrin (3b) >99 >99 >66 200

2 2b propylene oxide (3c) 74 >99 >66 200

3^[e] 2b propylene oxide (3c) >99 >99 >66 200

4 2b 1,2-butene oxide (3d) 19 42 28 84

5^[e] 2b 1,2-butene oxide (3d) 96 97 65 194

6 2b 1,2-hexene oxide (3e) 15 26 17 52

7^[e] 2b 1,2-hexene oxide (3e) 94 99 66 198

8 2b 1,2-epoxy-2-methylpropane (3f) n.d. n.d. - -

9^[e] 2b 1,2-epoxy-2-methylpropane (3f) n.d. n.d. - -

10 2b cyclohexene oxide (3g) - 0 - -

11^[e] 2b cyclohexene oxide (3g) 40 15 10 30

12 2b 4-vinylcyclohexene dioxide (3h) 99 25 17 50

13^[e] 2b 4-vinylcyclohexene dioxide (3h) >99 80 53 160

14 2b (cis)-limonene-1,2-oxide (3i) 0 7 5 14

15 2b stilbene oxide (3l) 0 0 - 0

16^[e] 2b stilbene oxide (3l) 0 0 - 0

17 2b allyl glycidyl ether (3m) >99 98 65 196

18 2b eugenol oxide (3n) >99 71 47 142

[a] Reaction conditions: neat, 250 µL of substrate (see the section below for the quantities), 2b = 0.5%, at 125 °C; P(CO2) = 0.8 MPa;

reaction time = 3 h. [b] Conversion and selectivity determined by ¹H NMR using 1,3,5-trimethylbenzene as internal standard (see General Catalytic Procedures: Method A). [c] Turnover frequency (molsub∙molcat-1∙reaction time^-1). [d] Turnover number (molsub∙molcat-1). [e] Catalyst is previously dissolved in 125 µL of propylene carbonate (see General Catalytic Procedures: Method B).

20

NMR of cyclic carbonates

Styrene carbonate (4a):

Styrene oxide (3a): 0.263 g, 2.19 mmol

Yield: 0.3554 g, 99% (isolated by precipitation in hexane)

1H NMR (400 MHz, CDCl3) δ 7.54 – 7.46 (m, 3H, HAr), 7.42 – 7.38 (m, 2H, HAr), 5.70 (t, J = 8.2 Hz, 1H, H1), 4.82 (t, J = 8.2 Hz, 1H, H2), 4.37 (t, J = 8.2 Hz, 1H, H1’).

Spectral data are consistent with literature values.^[5]

21 Epichlorohydrin carbonate(4b):

Epichlorohydrin (3b): 0.295 g, 3.19 mmol

Yield: 0.4309 g, 99% (isolated via column chromatography on silica gel, eluent: hexane ethyl acetate 7:3)

1H NMR (300 MHz, CDCl3) δ 5.02 – 4.96 (m, 1H, H2), 4.60 (pst, J = 8.6 Hz, 1H, H1),

4.43 (dd, J = 8.9, 5.8 Hz, 1H, H1’), 3.80 (dd, J = 12.1, 4.6 Hz, 1H, H3), 3.74 (dd, J = 12.1, 4.6 Hz, 1H, H3’).

Spectral data are consistent with literature values.^[5]

22 Propylene carbonate (4c):

Propylene oxide (3c): 0.2074 g, 0.36 mmol

Yield: 0.3737 g, 99% (purified from the catalyst via filtration)

1H NMR (300 MHz, CDCl3) δ 4.91 – 4.82 (m, 1H, H2), 4.56 (pst, J = 8.0 Hz, 1H, H1), 4.03 (pst, J = 7.8 Hz, 1H, H1’), 1.49 (d, J = 6.3 Hz, 3H, H3).

Spectral data are consistent with literature values.^[5]

23 1,2-Butene carbonate (4d):

1,2-Butene oxide (3d): 0.2070 g, 2.87 mmol

Yield: 93% (yield is calculated via internal standard technique)

1H NMR (400 MHz, CDCl3) δ 4.69 – 4.61 (m, 1H, H2), 4.52 (dd, J = 8.0, 7.0 Hz, 1H, H1), 4.07 (dd, J = 8.4, 7.0 Hz, 1H, H1), 1.83 – 1.70 (m, 2H, H3,3’), 1.00 (t, J = 7.4 Hz, 3H, H4).

Spectral data are consistent with literature values.^[5]

24 1,2-Hexene carbonate (4e):

1,2-Hexene oxide (3e): 0.210 g, 2.1 mmol

Yield: 93% (yield is calculated via internal standard technique)

1H NMR (300 MHz, CDCl3) δ 4.74 – 4.67 (m, 1H, H2), 4.54 (dd, 1H, J = 8.4, 7.0 Hz, H1), 4.08 (dd, 1H, J = 8.4, 7.0 Hz, H1’),

1.81 – 1.71 (m, 2H, CH2), 1.40 – 1.34 (m, 4H, CH2), 0.90 (t, 3H, J = 7.4 Hz, H6).

Spectral data are consistent with literature values.^[5]

25 4-(7-Oxabicyclo[4.1.0]heptan-3-yl)-1,3-dioxolan-2-one (4h):

1,2-Vinyl cyclohexene oxide (3h): 0.2721 g, 1.93 mmol

Yield: 0.2731 g, 77% (isolated via column chromatography on silica gel, eluent: hexane ethyl acetate 5:1)

1H NMR (300 MHz, CDCl3) δ 4.52 – 4.36 (m, 2H), 4.18 – 4.13 (m, 1H) partially overlapping with AcOEt, 3.26 – 3.17 (m, 2H), 2.35 – 1.08 (m, 7H).

Spectral data are consistent with literature values.^[5]

26 Allyl glycidyl carbonate (4m):

Allyl glycidyl ether (3h): 0.2411 g, 2.10 mmol

Yield: 92% (yield is calculated via internal standard technique)

1H NMR (400 MHz, CDCl3) δ 5.93 – 5.83 (m, 1H, H6), 5.30 (dd, J = 17.2, 1.5 Hz, 1H, H7), 5.23 (dd, J = 10.4, 1.2 Hz, 1H, H7’), 4.85 – 4.75 (m, 1H, H2), 4.51 (pst, J = 8.4 Hz, 1H, H1), 4.41 (dd, J = 8.3, 6.1 Hz, 1H, H1’), 4.11 – 4.02 (m, 2H, H5), 3.70 (dd, J = 11.0, 3.9 Hz, 1H, H3), 3.62 (dd, J = 11.0, 3.8 Hz, 1H, H3’).

Spectral data are consistent with literature values.^[5]

27 Eugenol carbonate (4n):

Eugenol epoxide (3n): 0.3000 g, 1.66 mmol

Yield: 0.2569 g, 69% (isolated via column chromatography on silica gel, eluent: hexane ethyl acetate 7:3) Elem. An. C11H12O5 Calcd: C 58.93%, H 5.39%; found: C 58.80%, H 5.10%

1H NMR (300 MHz, CDCl3) δ 6.88 (d, J = 8.0 Hz, 1H, H4), 6.74 (d, J = 1.6 Hz, 1H, H9), 6.69 (dd, J = 8.0, 1.6 Hz, 1H, H10), 5.69 (bs, 1H, H8), 4.96 – 4.89 (m, 1H, H2), 4.44 (t, J = 8.2 Hz, 1H, H1) 4.17 (dd, J = 8.5, 6.8 Hz, 1H, H1’), 3.90 (s, 3H, H6),

3.05 (dd, J = 12.4, 6.1 Hz, 2H, H3), 2.97 (dd, J = 12.4, 6.0 Hz, 1H, H3’).

13C NMR (75 MHz, CDCl3) δ 122.2 (s, C10), 114.7 (s, C4), 111.8 (s, C9), 77.1 (s, C2), 68.4 (s, C1), 56.0 (s, C6), 39.1 (s, C3). Quaternary carbons not detected.

28

Crystal structure determination

Prismatic colourless crystals of the compound 2a suitable for X-ray analysis were grown by slow evaporation from an aqueous solution at room temperature while prismatic colourless crystals of the compound 2b were obtained from slow evaporation of mother liquor after purification process. Single crystal X-ray diffraction experiments were performed on a Bruker Smart APEX II diffractometer with graphite monochromated Mo- Kα radiation (λ = 0.71073 Å) by the ω-scan method, within the limits 3.4° < 2θ < 52.7° < θ < 22.7 for 2a and 3.9° < 2θ < 52.7° for 2b. The frames were integrated and corrected for Lorentz-polarization effects with the Bruker SAINT software package⁶. The intensity data were then corrected for absorption by using SADABS⁷. No decay correction was applied. The structure of both compounds was solved by direct methods (SIR-97)⁸ and refined by iterative cycles of full-matrix least-squares on Fo² and Fourier-difference synthesis with SHELXL-97⁹ within the WinGX interface.¹⁰

Crystal data for 2a: (C11H18ClN4Zn) ⁺ (Cl) ^- 3/2H2O, triclinic space group 𝑃1̅ (n° 2), Z = 2, a = 7.8000(4), b = 8.9923(7), c = 12.1580(9) Å, α = 78.255(1), β = 88.493(1), γ = 75.167(1)°, V = 806.79(1) Å. Dc = 1.517 g cm⁻³, F(000) = 380, T = 298(2) K, μ(Mo-Kα) = 1.855 mm⁻¹. Total number of reflections recorded, to θmax = 26.369°, was 6179 of which 3277 were unique (Rint = 0.0098); 3144 were ‘observed’ with I > 2σ(I). Final R-values: wR2

= 0.0579 and R1 = 0.0229 for all data; R1 = 0.0216 for the ‘observed’ data.

All atoms are in general position. A water molecule (oxygen atom O2) is located very close to a cell vertex (site symmetry 1̅, Wyckoff letter a) and refined with an occupancy of 0.5. A second water molecule is present that shows a disorder over two positions (site symmetry 1, Wyckoff letter i) of its oxygen atom. The two sites, O1A and O1B, share the same hydrogens and were refined with a sof of 0.5. The hydrogen atoms of the ligand were placed in geometrically calculated positions and then refined using a riding model based on the positions of the parent atoms with Uiso = 1.2 Ueq. The hydrogen atoms (H12 and H13) attached to O1A and O1B were located from a difference Fourier map and refined isotropically, whereas it was not possible to determine the position of the hydrogens bound to O2. Restrains were applied to the distances between the oxygen and the hydrogen atoms (H12 and H13) of the O1A and O1B water molecules. A restrain was applied to the H12…H13 distance as well in order to obtain a reasonable value for the H-O-H angle.

Crystal data for 2b: (C11H18BrN4Zn) ⁺, (Br) ^-·H2O triclinic space group 𝑃1̅ (n° 2), Z = 2, a = 8.3278(8), b = 9.2464(9), c = 10.631(1) Å, α= 81.269(1), β = 89.239(1), γ = 89.991(1)°, V = 809.0(1) Å^3.. Dc = 1.845 g cm⁻³, F(000) = 444, T = 298(2) K, μ(Mo-Kα) = 6.454 mm⁻¹. Total number of reflections recorded, to θmax = 26.368°, was 6583 of which 3317 were unique (Rint = 0.0124); 2786 were ‘observed’ with I > 2σ(I). Final R-values: wR2

= 0.0744 and R1 = 0.0355 for all data; R1 = 0.0275 for the ‘observed’ data.

All atoms are in general position. The hydrogen atoms of the ligand were placed in geometrically calculated positions and then refined using a riding model based on the positions of the parent atoms with Uiso = 1.2 Ueq. The hydrogen atoms of the water molecule (H1W and H2W) were located from a difference Fourier map and refined isotropically. Their distance to the oxygen atom O was restrained to be equal within a standard deviation of 0.02. Furthermore, the distance H1W…H2W was restrained to a target value in order to retain a reasonable value for the H-O-H angle.

Full crystallographic data have been deposited with the Cambridge Crystallographic Data Centre (CCDC No.

2064861 for complex 2a and 2064860 for complex 2b). A copy of the data ca be obtained free of charge on application to CCDC, 12 Union Road, Cambridge CB2 IEZ, UK (Fax: +44 1223 336 033; e-mail:

deposit@ccdc.cam.ac.uk)

29 Table S8: Crystal data and structure refinement for 2a.

Identification code shelx

Empirical formula C11H20Cl2N4O1.50Zn

Formula weight 368.58

Temperature 298(2) K

Wavelength 0.71073 Å

Crystal system Triclinic

Space group P -1

Unit cell dimensions a = 7.8000(4) Å = 78.255(1)°.

b = 8.9923(7) Å = 88.493(1)°.

c = 12.1580(9) Å  = 75.167(1)°.

Volume 806.79(10) Å3

Z 2

Density (calculated) 1.517 Mg/m3

Absorption coefficient 1.855 mm-1

F(000) 380

Crystal size 0.500 x 0.174 x 0.142 mm3

Theta range for data collection 1.711 to 26.369°.

Index ranges -9<=h<=9, -11<=k<=11, -15<=l<=15

Reflections collected 6179

Independent reflections 3277 [R(int) = 0.0098]

Completeness to theta = 25.242° 99.6 %

Refinement method Full-matrix least-squares on F2

Data / restraints / parameters 3277 / 7 / 198

Goodness-of-fit on F2 1.044

Final R indices [I>2sigma(I)] R1 = 0.0216, wR2 = 0.0567

R indices (all data) R1 = 0.0229, wR2 = 0.0579

Extinction coefficient n/a

Largest diff. peak and hole 0.382 and -0.277 e.Å-3

30

Table S9: Atomic coordinates (x 104) and equivalent isotropic displacement parameters (Å2x 103) for 2a. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor.

________________________________________________________________________________

x y z U(eq)

________________________________________________________________________________

Zn 5339(1) 7075(1) 7024(1) 33(1)

Cl(2) 6674(1) 7237(1) 3254(1) 50(1)

Cl(1) 2469(1) 7675(1) 6595(1) 55(1)

N(1) 6456(2) 6241(2) 8622(1) 38(1)

N(4) 6443(2) 4536(2) 7043(1) 40(1)

N(3) 7244(2) 7348(2) 5858(1) 40(1)

N(2) 5875(2) 9176(2) 7483(1) 44(1)

C(1) 7064(2) 4701(2) 9006(1) 41(1)

C(11) 6979(3) 3659(2) 8191(2) 50(1)

C(8) 7746(3) 8823(2) 5863(2) 51(1)

C(9) 8680(2) 5894(2) 6186(2) 46(1)

C(10) 7906(3) 4506(2) 6238(2) 50(1)

C(5) 6541(2) 7275(2) 9261(1) 45(1)

C(6) 5841(3) 8979(2) 8710(2) 56(1)

C(7) 7646(2) 9169(2) 7031(2) 50(1)

C(2) 7726(3) 4135(3) 10105(2) 59(1)

C(4) 7201(3) 6769(3) 10350(2) 60(1)

C(3) 7761(3) 5183(3) 10773(2) 67(1)

O(2) 8951(7) 10190(7) 9946(4) 115(2)

O(1A) 9127(10) 9289(9) 2268(7) 78(2)

O(1B) 8660(12) 9696(11) 1823(6) 91(2)

________________________________________________________________________________

31 Table S10: Bond lengths [Å] and angles [°] for 2a.

_____________________________________________________

Zn-N(3) 2.053(1)

Zn-N(1) 2.063(1)

Zn-Cl(1) 2.2139(5)

Zn-N(2) 2.214(2)

Zn-N(4) 2.220(1)

N(1)-C(1) 1.331(2)

N(1)-C(5) 1.343(2)

N(4)-C(11) 1.469(2)

N(4)-C(10) 1.482(2)

N(3)-C(8) 1.477(2)

N(3)-C(9) 1.478(2)

N(2)-C(6) 1.466(3)

N(2)-C(7) 1.472(2)

C(1)-C(2) 1.391(3)

C(1)-C(11) 1.509(3)

C(8)-C(7) 1.510(3)

C(9)-C(10) 1.509(3)

C(5)-C(4) 1.377(3)

C(5)-C(6) 1.505(3)

C(2)-C(3) 1.369(3)

C(4)-C(3) 1.373(4)

N(3)-Zn-N(1) 110.99(5) N(3)-Zn-Cl(1) 123.48(4) N(1)-Zn-Cl(1) 125.50(4)

N(3)-Zn-N(2) 83.33(6)

N(1)-Zn-N(2) 76.47(6)

Cl(1)-Zn-N(2) 106.71(4)

N(3)-Zn-N(4) 83.67(6)

N(1)-Zn-N(4) 77.77(5)

Cl(1)-Zn-N(4) 107.94(4) N(2)-Zn-N(4) 144.59(5) C(1)-N(1)-C(5) 121.2(2)

C(1)-N(1)-Zn 120.1(1)

C(5)-N(1)-Zn 118.8(1)

C(11)-N(4)-C(10) 115.0(2) C(11)-N(4)-Zn 110.7(1)

32 C(10)-N(4)-Zn 103.8(1)

C(8)-N(3)-C(9) 115.3(2)

C(8)-N(3)-Zn 109.9(1)

C(9)-N(3)-Zn 103.8 (1) C(6)-N(2)-C(7) 113.1(2)

C(6)-N(2)-Zn 108.4(1)

C(7)-N(2)-Zn 102.9(1)

N(1)-C(1)-C(2) 120.0(2) N(1)-C(1)-C(11) 116.3(2) C(2)-C(1)-C(11) 123.7(2) N(4)-C(11)-C(1) 113.4(1) N(3)-C(8)-C(7) 110.8(1) N(3)-C(9)-C(10) 108.3(2) N(4)-C(10)-C(9) 111.4(1) N(1)-C(5)-C(4) 120.8 (2) N(1)-C(5)-C(6) 115.4(2) C(4)-C(5)-C(6) 123.8(2) N(2)-C(6)-C(5) 110.5(1) N(2)-C(7)-C(8) 110.2(2) C(3)-C(2)-C(1) 119.0(2) C(3)-C(4)-C(5) 118.6(2) C(2)-C(3)-C(4) 120.3(2)

_____________________________________________________________

Symmetry transformations used to generate equivalent atoms:

33

Table S11: Anisotropic displacement parameters (Å2x 103) for 2a. The anisotropic

displacement factor exponent takes the form: -22[ h2a*2U11 + ... + 2 h k a* b* U12 ] ______________________________________________________________________________

U11 U22 U33 U23 U13 U12

______________________________________________________________________________

Zn 26(1) 37(1) 35(1) -7(1) -2(1) -6(1)

Cl(2) 66(1) 45(1) 40(1) -11(1) -8(1) -15(1)

Cl(1) 29(1) 52(1) 79(1) -1(1) -11(1) -9(1)

N(1) 35(1) 44(1) 31(1) -9(1) 2(1) -5(1)

N(4) 39(1) 40(1) 44(1) -12(1) 0(1) -10(1)

N(3) 38(1) 52(1) 31(1) -7(1) 0(1) -14(1)

N(2) 40(1) 38(1) 52(1) -13(1) -7(1) -6(1)

C(1) 34(1) 48(1) 38(1) -1(1) 4(1) -9(1)

C(11) 55(1) 36(1) 53(1) -3(1) 5(1) -4(1)

C(8) 44(1) 54(1) 54(1) 4(1) 0(1) -22(1)

C(9) 35(1) 59(1) 43(1) -16(1) 10(1) -8(1)

C(10) 52(1) 53(1) 47(1) -24(1) 9(1) -7(1)

C(5) 41(1) 59(1) 36(1) -18(1) 4(1) -10(1)

C(6) 61(1) 53(1) 57(1) -29(1) -4(1) -5(1)

C(7) 44(1) 45(1) 66(1) -11(1) -7(1) -19(1)

C(2) 54(1) 64(1) 46(1) 13(1) -4(1) -12(1)

C(4) 63(1) 87(2) 36(1) -21(1) 1(1) -23(1)

C(3) 67(1) 99(2) 32(1) -1(1) -7(1) -26(1)

O(2) 108(3) 139(4) 96(3) -2(3) 2(3) -46(3)

O(1A) 58(3) 72(3) 106(5) -22(3) 18(3) -19(3)

O(1B) 80(5) 98(5) 107(6) -34(4) 36(4) -37(4)

______________________________________________________________________________

34 Table S12: Crystal data and structure refinement for 2b.

Identification code CM52beuta

Empirical formula C11H20Br2N4OZn

Formula weight 449.50

Temperature 298(2) K

Wavelength 0.71073 Å

Crystal system Triclinic

Space group P -1

Unit cell dimensions a = 8.3278(8) Å  = 81.269(1)°.

b = 9.2464(9) Å = 89.239(1)°.

c = 10.631(1) Å  = 89.991(1)°.

Volume 809.0(1) Å3

Z 2

Density (calculated) 1.845 Mg/m3

Absorption coefficient 6.454 mm-1

F(000) 444

Crystal size 0.214 x 0.152 x 0.121 mm3

Theta range for data collection 1.938 to 26.368°.

Index ranges -10<=h<=10, -11<=k<=11, -13<=l<=13

Reflections collected 6583

Independent reflections 3317 [R(int) = 0.0124]

Completeness to theta = 25.242° 100.0 %

Absorption correction Empirical

Max. and min. transmission 0.7463 and 0.5747

Refinement method Full-matrix least-squares on F2

Data / restraints / parameters 3317 / 2 / 180

Goodness-of-fit on F2 1.027

Final R indices [I>2sigma(I)] R1 = 0.0275, wR2 = 0.0712

R indices (all data) R1 = 0.0355, wR2 = 0.0744

Extinction coefficient n/a

Largest diff. peak and hole 0.898 and -0.480 e.Å-3

35

Table S13: Atomic coordinates (x 104) and equivalent isotropic displacement parameters (Å2x 103) for 2b. U(eq) is defined as one third of the trace of the orthogonalized Uij tensor.

________________________________________________________________________________

x y z U(eq)

________________________________________________________________________________

C(1) 7434(4) 6079(4) 9625(3) 40(1)

C(2) 7786(4) 4683(4) 10205(3) 51(1)

C(3) 7197(5) 3520(4) 9684(4) 59(1)

C(4) 6308(4) 3759(4) 8588(4) 54(1)

C(5) 5991(4) 5184(3) 8050(3) 41(1)

C(6) 5058(4) 5591(4) 6848(4) 51(1)

C(7) 7012(5) 7113(4) 5525(4) 59(1)

C(8) 7736(5) 8583(5) 5327(3) 61(1)

C(9) 9338(4) 8805(4) 7266(3) 51(1)

O 9444(5) 5128(5) 2974(3) 96(1)

C(10) 9170(4) 9390(4) 8520(4) 55(1)

C(11) 8016(4) 7428(4) 10128(3) 51(1)

N(1) 6529(3) 6308(3) 8593(2) 35(1)

N(2) 7754(3) 8783(3) 9252(2) 42(1)

N(3) 7871(3) 9174(3) 6528(3) 44(1)

N(4) 5444(3) 7078(3) 6248(3) 45(1)

Zn 6010(1) 8395(1) 7721(1) 34(1)

Br(1) 3822(1) 9914(1) 8034(1) 48(1)

Br(2) 7989(1) 2812(1) 5543(1) 58(1)

________________________________________________________________________________

36 Table S14: Bond lengths [Å] and angles [°] for 2b.

_____________________________________________________

C(1)-N(1) 1.330(4)

C(1)-C(2) 1.377(5)

C(1)-C(11) 1.512(5)

C(2)-C(3) 1.376(6)

C(2)-H(2) 0.9300

C(3)-C(4) 1.379(6)

C(3)-H(3) 0.9300

C(4)-C(5) 1.381(5)

C(4)-H(4) 0.9300

C(5)-N(1) 1.343(4)

C(5)-C(6) 1.503(5)

C(6)-N(4) 1.460(4)

C(6)-H(6A) 0.9700

C(6)-H(6B) 0.9700

C(7)-C(8) 1.472(6)

C(7)-N(4) 1.504(5)

C(7)-H(7A) 0.9700

C(7)-H(7B) 0.9700

C(8)-N(3) 1.468(5)

C(8)-H(8A) 0.9700

C(8)-H(8B) 0.9700

C(9)-N(3) 1.473(4)

C(9)-C(10) 1.518(5)

C(9)-H(9A) 0.9700

C(9)-H(9B) 0.9700

O-H(2W) 0.83(2)

O-H(1W) 0.84(3)

C(10)-N(2) 1.468(4)

C(10)-H(10A) 0.9700 C(10)-H(10B) 0.9700

C(11)-N(2) 1.461(4)

C(11)-H(11A) 0.9700 C(11)-H(11B) 0.9700

N(1)-Zn 2.058(2)

N(2)-Zn 2.264(3)

N(2)-H(2A) 0.9800

N(3)-Zn 2.050(3)

37

N(3)-H(3A) 0.9800

N(4)-Zn 2.181(3)

N(4)-H(4A) 0.9800

Zn-Br(1) 2.3516(5)

N(1)-C(1)-C(2) 121.1(3) N(1)-C(1)-C(11) 116.3(3) C(2)-C(1)-C(11) 122.5(3) C(3)-C(2)-C(1) 118.5(3) C(3)-C(2)-H(2) 120.7 C(1)-C(2)-H(2) 120.7 C(2)-C(3)-C(4) 120.3(3) C(2)-C(3)-H(3) 119.9 C(4)-C(3)-H(3) 119.9 C(3)-C(4)-C(5) 118.5(3) C(3)-C(4)-H(4) 120.7 C(5)-C(4)-H(4) 120.7 N(1)-C(5)-C(4) 120.5(3) N(1)-C(5)-C(6) 115.7(3) C(4)-C(5)-C(6) 123.7(3) N(4)-C(6)-C(5) 110.9(3) N(4)-C(6)-H(6A) 109.5 C(5)-C(6)-H(6A) 109.5 N(4)-C(6)-H(6B) 109.5 C(5)-C(6)-H(6B) 109.5 H(6A)-C(6)-H(6B) 108.1 C(8)-C(7)-N(4) 111.8(3) C(8)-C(7)-H(7A) 109.3 N(4)-C(7)-H(7A) 109.3 C(8)-C(7)-H(7B) 109.3 N(4)-C(7)-H(7B) 109.3 H(7A)-C(7)-H(7B) 107.9 N(3)-C(8)-C(7) 111.7(3) N(3)-C(8)-H(8A) 109.3 C(7)-C(8)-H(8A) 109.3 N(3)-C(8)-H(8B) 109.3 C(7)-C(8)-H(8B) 109.3 H(8A)-C(8)-H(8B) 107.9 N(3)-C(9)-C(10) 108.4(3)

38 N(3)-C(9)-H(9A) 110.0

C(10)-C(9)-H(9A) 110.0 N(3)-C(9)-H(9B) 110.0 C(10)-C(9)-H(9B) 110.0 H(9A)-C(9)-H(9B) 108.4

H(2W)-O-H(1W) 108(4)

N(2)-C(10)-C(9) 111.8(3) N(2)-C(10)-H(10A) 109.3 C(9)-C(10)-H(10A) 109.3 N(2)-C(10)-H(10B) 109.3 C(9)-C(10)-H(10B) 109.3 H(10A)-C(10)-H(10B) 107.9 N(2)-C(11)-C(1) 113.3(3) N(2)-C(11)-H(11A) 108.9 C(1)-C(11)-H(11A) 108.9 N(2)-C(11)-H(11B) 108.9 C(1)-C(11)-H(11B) 108.9 H(11A)-C(11)-H(11B) 107.7 C(1)-N(1)-C(5) 120.9(3)

C(1)-N(1)-Zn 121.1(2)

C(5)-N(1)-Zn 117.9(2)

C(11)-N(2)-C(10) 115.7(3) C(11)-N(2)-Zn 110.3(2) C(10)-N(2)-Zn 103.1(2) C(11)-N(2)-H(2A) 109.1 C(10)-N(2)-H(2A) 109.1

Zn-N(2)-H(2A) 109.1

C(8)-N(3)-C(9) 116.8(3)

C(8)-N(3)-Zn 109.2(2)

C(9)-N(3)-Zn 105.4(2)

C(8)-N(3)-H(3A) 108.4 C(9)-N(3)-H(3A) 108.4

Zn-N(3)-H(3A) 108.4

C(6)-N(4)-C(7) 110.7(3)

C(6)-N(4)-Zn 109.0(2)

C(7)-N(4)-Zn 101.6(2)

C(6)-N(4)-H(4A) 111.7 C(7)-N(4)-H(4A) 111.7

Zn-N(4)-H(4A) 111.7

39

N(3)-Zn-N(1) 109.6(1)

N(3)-Zn-N(4) 84.6(1)

N(1)-Zn-N(4) 77.6(1)

N(3)-Zn-N(2) 83.0(1)

N(1)-Zn-N(2) 77.0(1)

N(4)-Zn-N(2) 146.1(1)

N(3)-Zn-Br(1) 120.3(8) N(1)-Zn-Br(1) 129.98(7) N(4)-Zn-Br(1) 109.74(8) N(2)-Zn-Br(1) 103.78(7)

_____________________________________________________________

Symmetry transformations used to generate equivalent atoms:

40

Table S15: Anisotropic displacement parameters (Å2x 103) for 2b. The anisotropic

displacement factor exponent takes the form: -22[ h2a*2U11 + ... + 2 h k a* b* U12 ] ______________________________________________________________________________

U11 U22 U33 U23 U13 U12

______________________________________________________________________________

C(1) 35(2) 50(2) 33(2) -4(1) 6(1) 8(1)

C(2) 47(2) 59(2) 42(2) 8(2) 5(1) 14(2)

C(3) 61(2) 41(2) 68(3) 11(2) 16(2) 7(2)

C(4) 50(2) 39(2) 73(3) -9(2) 15(2) -5(2)

C(5) 35(2) 39(2) 51(2) -10(1) 10(1) -4(1)

C(6) 45(2) 51(2) 60(2) -23(2) -6(2) -5(2)

C(7) 72(3) 64(2) 45(2) -22(2) 4(2) 2(2)

C(8) 61(2) 80(3) 43(2) -12(2) 3(2) 4(2)

C(9) 35(2) 66(2) 53(2) -14(2) 6(1) -7(2)

O 106(3) 116(3) 64(2) -4(2) -21(2) -30(3)

C(10) 46(2) 65(2) 58(2) -19(2) -5(2) -14(2)

C(11) 53(2) 61(2) 40(2) -15(2) -11(2) 13(2)

N(1) 33(1) 36(1) 36(1) -7(1) 1(1) 5(1)

N(2) 41(1) 44(2) 43(2) -17(1) -5(1) 5(1)

N(3) 46(2) 43(2) 41(2) -6(1) 4(1) -2(1)

N(4) 49(2) 47(2) 42(2) -13(1) -12(1) 2(1)

Zn 31(1) 35(1) 37(1) -9(1) -2(1) 6(1)

Br(1) 45(1) 54(1) 47(1) -10(1) 1(1) 17(1)

Br(2) 55(1) 50(1) 69(1) -10(1) -4(1) 2(1)

______________________________________________________________________________

41

BIBLIOGRAPHY

[1] A. J. Wessel, J. W. Schultz, F. Tang, H. Duan, L. M. Mirica, Org. Biomol. Chem. 2017, 15, 9923-9931.

[2] N. Panza, A. di Biase, S. Rizzato, E. Gallo, G. Tseberlidis, A. Caselli, Eur. J. Org. Chem. 2020, 2020, 6635- 6644.

[3] M. S. Kumar, M. Vinod, N. Amol, S. Inamdur, Process for the preparation of 3-bromo-4- fluorobenzaldehyde WO2010086877A2 2010-08-05.

[4] E. M. Elgendy, S. A. Khayyat, Russian Journal of Organic Chemistry 2008, 44, 823-829.

[5] J. Steinbauer, A. Spannenberg, T. Werner, Green Chem. 2017, 19, 3769-3779.

[6] Bruker AXS Inc. SAINT. Madison, WI, USA 2007.

[7] Bruker AXS Inc. SADABS Area-Detector Absorption Correction Program. Madison, WI, USA 2001 [8] A. Altomare, G. Cascarano, C. Giacovazzo, A. Guagliardi, M. C. Burla, G. Polidori, M. Camalli, J. Appl.

Crystallogr. 1994, 27, 435-436.

[9] G. Sheldrick, Acta Crystallogr. A 2015, 71, 3-8.

[10] L. J. Farrugia, J. Appl. Crystallogr. 1999, 32, 837-838.