Alkali Metal Hydridotriphenylborates [(L)M][HBPh3] (M = Li, Na, K): Chemoselective Catalysts for Carbonyl and CO2 Hydroboration

Supporting Information Alkali Metal Hydridotriphenylborates [(L)M][HBPh3] (M = Li, Na, K): Chemoselective Catalysts for Carbonyl and CO2 Hydroboration Debabrata Mukherjee, Hassan Osseili, Thomas P. Spaniol, and Jun Okuda* Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1, 52056 Aachen, Germany Table of Contents General Procedures... S1 Synthetic procedures and spectroscopic data for compounds 1-12... S2 In situ characterization of [(L)Li][Ph3B OCHPh2] and [(L)K][Ph3B OCH2Ph]...S24 Synthesis and characterization of [nbu4n][hbph3]... S26 Catalysis...S28 NMR spectra of a 1:3.5 mixture of 4 and HBpin... S34 Single crystal X-ray diffraction... S35 References... S36 General procedures. All reactions were performed under a dry argon atmosphere using standard Schlenk techniques or under argon atmosphere in a glovebox, unless otherwise indicated. Prior to use, glasswares were dried overnight at 130 C and solvents were dried, distilled and degassed using standard methods. M[N(SiHMe2)2] (M = Li, Na, K), S1 Tris(2-aminoethyl)amine (Me6TREN), S2 and B(C6F5)3 S3 were synthesized according to the literature procedures. BPh3 (98% pure) was purchased from Sigma-Aldrich and recrystallized from diethyl ether solution at 35 C prior to use. CO2 (purity level 5.0, equals to 99.990% purity) was purchased from Westfalen, Germany and passed through a column of P4O10 with moisture indicator while using in the Schlenk line. 1 H, 13 C{ 1 H}, 11 B, and 29 Si{ 1 H} NMR spectra were recorded on a Bruker DRX400 spectrometer at ambient temperature unless otherwise mentioned. Chemical shifts (δ in ppm) in the 1 H and 13 C{ 1 H} NMR spectra were referenced to the residual signals of the deuterated solvents. Abbreviations for NMR spectra: s (singlet), d (doublet), t (triplet), q (quartet), sep (septet), br (broad). IR spectra were recorded on KBr pellets using an AVATAR 360 FT-IR spectrometer. Elemental analyses were performed on an elementar vario EL machine. X-ray diffraction data were collected on a Bruker APEX II diffractometer. Single crystal diffraction data is reported in crystallographic information files (cif) accompanying this document. S1

Synthetic procedures and spectroscopic data for compounds 1-12. [(Me6TREN)Li][N(SiHMe2)2] (1). A mixture of Li(N(SiHMe2)2 (0.300 g, 2.154 mmol) and Me6TREN (0.497 g, 2.157 mmol) in n-pentane (7 ml) was stirred for 0.5 h at room temperature. Removal of the volatiles under reduced pressure afforded analytically pure [(Me6TREN)Li][N(SiHMe2)2] (1, 0.781 g, 2.113 mmol, 98% yield) as a colorless powder. 1 H NMR (400 MHz, benzene-d6): δ 5.15 (sept, 3 JHH = 3.2 Hz, 2 H, SiHMe2), 2.28 (br, m, 6 H, CH2), 2.08 (s, 18 H, NMe2), 1.98 (br, m, 6 H, CH2), 0.58 (d, 3 JHH = 3.2 Hz, 12 H, SiHMe2). 13 C{ 1 H} NMR (benzene-d6, 100 MHz): δ 57.3 (CH2), 51.6 (CH2), 46.1 (NMe2), 6.9 (SiHMe2). 29 Si{ 1 H} NMR (80 MHz, benzene-d6): δ 28.8. 7 Li{ 1 H} NMR (156 MHz, benzene-d6): δ 0.7. IR (KBr, cm 1 ): 2008 ( SiH). Anal. Calcd. for C16H44N5Si2Li: C, 51.99; H, 12.00; N, 18.95. Found: C, 51.77; H, 11.74; N, 19.07. Figure S1. 1 H NMR spectrum of [(Me 6TREN)Li][N(SiHMe 2) 2] in benzene-d 6. Figure S2. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)Li][N(SiHMe 2) 2] in benzene-d 6. S2

Figure S3. 29 Si{ 1 H} NMR spectrum of [(Me 6TREN)Li][N(SiHMe 2) 2] in benzene-d 6. Figure S4. 7 Li{ 1 H} NMR spectrum of [(Me 6TREN)Li][N(SiHMe 2) 2] in benzene-d 6. wave number (cm 1 ) Figure S5. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)Li][N(SiHMe 2) 2]. S3

[(Me6TREN)Na][N(SiHMe2)2] (2). A mixture of Na(N(SiHMe2)2 (0.050 g, 0.322 mmol) and Me6TREN (0.074 g, 0.321 mmol) in THF (5 ml) was stirred for 0.5 h at room temperature. Removal of the volatiles under reduced pressure afforded analytically pure [(Me6TREN)Na][N(SiHMe2)2] (2, 0.121 g, 0.314 mmol, 97% yield) as a colorless powder. 1 H NMR (400 MHz, benzene-d6): δ 5.30 (sept, 3 JHH = 2.8 Hz, 2 H, SiHMe2), 2.09 (s, 18 H, NMe2), 1.78 (br, m, 12 H, CH2), 0.65 (d, 3 JHH = 2.8 Hz, 12 H, SiHMe2). 13 C{ 1 H} NMR (benzene-d6, 100 MHz): δ 57.9 (CH2), 52.2 (CH2), 46.0 (NMe2), 7.5 (SiHMe2). 29 Si{ 1 H} NMR (80 MHz, benzene-d6): δ 29.8. IR (KBr, cm 1 ): 2019 ( SiH). Anal. Calcd. for C16H44N5Si2Na: C, 49.82; H, 11.50; N, 18.16. Found: C, 49.65; H, 11.38; N, 18.40. Figure S6. 1 H NMR spectrum of [(Me 6TREN)Na][N(SiHMe 2) 2] in benzene-d 6. Figure S7. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)Na][N(SiHMe 2) 2] in benzene-d 6. S4

Figure S8. 29 Si{ 1 H} NMR spectrum of [(Me 6TREN)Na][N(SiHMe 2) 2] in benzene-d 6. wave number (cm 1 ) Figure S9. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)Na][N(SiHMe 2) 2]. [(Me6TREN)K][N(SiHMe2)2] (3). A mixture of K(N(SiHMe2)2 (0.100 g, 0.583 mmol) and Me6TREN (0.135 g, 0.586 mmol) in THF (5 ml) was stirred for 0.5 h at room temperature. Removal of the volatiles under reduced pressure afforded analytically pure [(Me6TREN)K][N(SiHMe2)2] (3, 0.209 g, 0.521 mmol, 89% yield) as an yellowish oily substance. 1 H NMR (benzene-d6, 400 MHz): δ 5.40 (sept, 3 JHH = 3.2 Hz, 2 H, SiHMe2), 2.01 (s, 18 H, NMe2), 1.99 (m, 6 H, CH2), 1.95 (m, 6 H, CH2), 0.55 (d, 3 JHH = 3.2 Hz, 12 H, SiHMe2). 13 C{ 1 H} NMR (100 MHz, benzene-d6): δ 57.9 (CH2), 52.7 (CH2), 45.7 (NMe2), 7.1 (SiHMe2). 29 Si{ 1 H} NMR (benzene-d8, 80 MHz): δ 33.4. IR (KBr, cm 1 ): 1982 ( SiH). Anal. Calcd. for C16H44N5Si2K: C, 47.83; H, 11.04; N, 17.43. Found: C, 48.04; H, 11.29; N, 17.49. S5

Figure S10. 1 H NMR spectrum of [(Me 6TREN)K][N(SiHMe 2) 2] in benzene-d 6. Figure S11. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)K][N(SiHMe 2) 2] in benzene-d 6. Figure S12. 29 Si{ 1 H} NMR spectrum of [(Me 6TREN)K][N(SiHMe 2) 2] in benzene-d 6. S6

wave number (cm 1 ) Figure S13. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)K][N(SiHMe 2) 2]. [(Me6TREN)Li][HBPh3] (4). A solution of BPh3 (0.102 g, 0.421 mmol) in 2 ml of THF was added dropwise to a solution of [(Me6TREN)Li][(N(SiHMe2)2] (0.154 g, 0.417 mmol) in 1 ml of THF. The resulting mixture was stirred for 2 h at room temperature. The solution was then concentrated under reduced pressure. Addition of n-pentane (5 ml) precipitated a white solid, which was further washed with fresh n-pentane (3 x 2 ml) and finally dried under vacuum to obtain analytically pure [(Me6TREN)Li][HBPh3] (4, 0.172 g, 0.358 mmol, 86% yield) as colorless crystals. X-ray quality single crystals were obtained from slow n-hexane diffusion into a concentrated THF solution of 4 at 35 C. 1 H NMR (400 MHz, THF-d8): δ 7.24 (m, 6 H, o-aryl), 6.82 (m, 6 H, m- aryl), 6.66 (m, 3 H, p-aryl), 3.56 (br, q, 1 H, HB), 2.49 (t, 3 JHH = 6.3 Hz, 6 H, CH2), 2.31 (t, 3 JHH = 6.3 Hz, 6 H, CH2), 2.16 (s, 18 H, NMe2). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 166.3 (ipso-aryl), 136.7 (o-aryl), 126.1 (m-aryl), 121.7 (p-aryl), 58.9 (CH2), 53.0 (CH2), 46.4 (NMe2). 11 B NMR (128 MHz, THF-d8): δ 8.2 (d, 1 JBH = 79 Hz). 7 Li{ 1 H} NMR (156 MHz, THF-d8): δ 2.34. IR (KBr, cm 1 ): 2225-1966 (multiple resonances, BH). Anal. Calcd. for C30H46BN4Li: C, 74.99; H, 9.65; N, 11.66. Found: C, 74.64; H, 9.59; N, 11.48. Figure S14. 1 H NMR spectrum of [(Me 6TREN)Li][HBPh 3] in THF-d 8. S7

Figure S15. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)Li][HBPh 3] in THF-d 8. Figure S16. 7 Li{ 1 H} NMR spectrum of [(Me 6TREN)Li][HBPh 3] in THF-d 8. Figure S17. 11 B NMR spectrum of [(Me 6TREN)Li][HBPh 3] in THF-d 8. S8

wave number (cm 1 ) Figure S18. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)Li][HBPh 3]. [(Me6TREN)Na][HBPh3] (5). A solution of BPh3 (0.150 g, 0.620 mmol) in 2 ml of THF was added dropwise to a solution of [(Me6TREN)Na][N(SiHMe2)2] (0.238 g, 0.617 mmol) in 1 ml of THF. The resulting mixture was stirred for 2 h at room temperature. The solution was then concentrated under reduced pressure. Addition of n-pentane (5 ml) precipitated a white solid, which was further washed with fresh n-pentane (3 x 2 ml) and finally dried under vacuum to obtain analytically pure [(Me6TREN)Na][HBPh3] (5, 0.298 g, 0.600 mmol, 97% yield) as colorless crystals. Poor quality single crystals were obtained from slow n-hexane diffusion into a concentrated THF solution of 5 at 35 C. 1 H NMR (400 MHz, THF-d8): δ 7.26 (m, 6 H, o-aryl), 6.88 (m, 6 H, m- aryl), 6.72 (m, 3 H, p-aryl), 3.24 (br, q, 1 H, HB), 2.48 (m, 6 H, CH2), 2.31 (m, 6 H, CH2), 2.15 (s, 18 H, NMe2). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 164.2 (ipso-aryl), 136.5 (o-aryl), 126.5 (m-aryl), 122.4 (p-aryl), 58.8 (CH2), 53.2 (CH2), 46.2 (NMe2). 11 B NMR (128 MHz, THF-d8): δ 8.2 (d, 1 JBH = 76 Hz). IR (KBr, cm 1 ): 2227-2011 (multiple resonances, BH). Anal. Calcd. for C30H46BN4Na: C, 72.57; H, 9.34; N, 11.28. Found: C, 72.28; H, 9.42; N, 11.27. Figure S19. 1 H NMR spectrum of [(Me 6TREN)Na][HBPh 3] in THF-d 8. S9

Figure S20. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)Na][HBPh 3] in THF-d 8. Figure S21. 11 B NMR spectrum of [(Me 6TREN)Na][HBPh 3] in THF-d 8. wave number (cm 1 ) Figure S22. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)Na][HBPh 3]. S10

[(Me6TREN)K][HBPh3] (6). A solution of BPh3 (0.093 g, 0.384 mmol) in 2 ml of THF was added dropwise to a solution of [(Me6TREN)K][N(SiHMe2)2] (0.153 g, 0.381 mmol) in 1 ml of THF. The resulting mixture was stirred for 2 h at room temperature. The solution was then concentrated under reduced pressure. Addition of n-pentane (5 ml) precipitated a white solid, which was further washed with fresh n-pentane (3 x 2 ml) and finally dried under vacuum to obtain analytically pure [(Me6TREN)K][HBPh3] (6, 0.179 g, 0.349 mmol, 92% yield) as a colorless crystals. X-ray quality single crystals were obtained from slow n-hexane diffusion into a concentrated THF solution of 6 at 35 C. 1 H NMR (400 MHz, THF-d8): δ 7.31 (m, 6 H, o-aryl), 6.94 (m, 6 H, m- aryl), 6.78 (m, 3 H, p-aryl), 3.28 (br, s, 1 H, HB), 2.54 (m, 6 H, CH2), 2.30 (m, 6 H, CH2), 2.15 (s, 18 H, NMe2). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 163.8 (ipso-aryl), 136.3 (o-aryl), 126.9 (m-aryl), 122.9 (p-aryl), 59.3 (CH2), 54.5 (CH2), 46.4 (NMe2). 11 B NMR (128 MHz, THF-d8): δ 8.0 (d, 1 JBH = 76 Hz). IR (KBr, cm 1 ): 2196-1994 (multiple resonances, BH). Anal. Calcd. for C30H46BN4K: C, 70.29; H, 9.05; N, 10.93. Found: C, 70.20; H, 9.14; N, 10.82. Figure S23. 1 H NMR spectrum of [(Me 6TREN)K][HBPh 3] in THF-d 8. S11

Figure S24. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)K][HBPh 3] in THF-d 8. Figure S25. 11 B NMR spectrum of [(Me 6TREN)K][HBPh 3] in THF-d 8. wave number (cm 1 ) Figure S26. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)K][HBPh 3]. [(Me6TREN)Li][HCO2BPh3] (7). A solution of [(Me6TREN)Li][HBPh3] (0.100 g, 0.208 mmol) in 2 ml of THF in a 25 ml Schlenk tube was degassed following three cycles of freeze-pump-thaw. The head space of the flask was filled with CO2 (1 atm). After 30 min, all volatiles were removed under reduced pressure and the residue was washed with n-pentane (3 x 5 ml). Finally, drying under vacuum afforded analytically pure [(Me6TREN)Li][HCO2BPh3] (7, 0.092 g, 0.175 mmol, 84% yield) as a white powder. X-ray quality single crystals were obtained from a concentrated THF solution of 7 at 35 C. 1 H NMR (400 MHz, THF-d8): δ 8.30 (s, 1 H, OCHO), 7.29 (m, 6 H, o- aryl), 6.99 (m, 6 H, m-aryl), 6.89 (m, 3 H, p-aryl), 2.54 (t, 3 JHH = 6.0 Hz, 6 H, CH2), 2.36 (t, 3 JHH = 6.0 Hz, 6 H, CH2), 2.19 (s, 18 H, NMe2). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 171.7 (OCHO), 157.2 (ipso-aryl), 134.7 (o-aryl), 126.9 (m-aryl), 124.4 (p-aryl), 58.2 (CH2), 52.4 S12

(CH2), 46.1 (NMe2). 11 B NMR (128 MHz, THF-d8): δ 4.3 (br). 7 Li{ 1 H} NMR (156 MHz, THFd8): δ 0.1. IR (KBr, cm 1 ): 1677 ( CO, asym). Anal. Calcd. for C31H47BN4O2Li: C, 70.02; H, 9.02; N, 10.66. Found: C, 69.96; H, 8.90; N, 10.81. Figure S27. 1 H NMR spectrum of [(Me 6TREN)Li][HCO 2BPh 3] in THF-d 8. Figure S28. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)Li][HCO 2BPh 3] in THF-d 8. Figure S29. 11 B NMR spectrum of [(Me 6TREN)Li][HCO 2BPh 3] in THF-d 8. S13

Figure S30. 7 Li{ 1 H} NMR spectrum of [(Me 6TREN)Li][HCO 2BPh 3] in THF-d 8. wave number (cm 1 ) Figure S31. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)Li][HCO 2BPh 3]. [(Me6TREN)Na][HCO2BPh3] (8). A solution of [(Me6TREN)Na][HBPh3] (0.100 g, 0.201 mmol) in 2 ml of THF in a 25 ml Schlenk tube was degassed following three cycles of freeze-pump-thaw. The head space of the flask was then filled with CO2 (1 atm). After 30 min, all volatiles were removed under vacuum and the residue was washed with n-pentane (3 x 5 ml). Finally drying under vacuum afforded analytically pure [(Me6TREN)Na][HCO2BPh3] (8, 0.094 g, 0.174 mmol, 87% yield) as a white powder. X-ray quality single crystals were obtained from a concentrated THF solution of 8 at 35 C. 1 H NMR (400 MHz, THF-d8): δ 8.30 (s, 1 H, OCHO), 7.28 (m, 6 H, o-aryl), 7.00 (m, 6 H, m-aryl), 6.89 (m, 3 H, p-aryl), 2.53 (t, 3 JHH = 6.4 Hz, 6 H, CH2), 2.33 (t, 3 JHH = 6.4 Hz, 6 H, CH2), 2.18 (s, 18 H, NMe2). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 171.5 (OCHO), 157.5 (ipso-aryl), 134.8 (o-aryl), 126.9 (m-aryl), 124.5 (p-aryl), 59.0 (CH2), 53.7 (CH2), 46.2 (NMe2). 11 B NMR (128 MHz, THF-d8): δ 4.5 (br). IR (KBr, cm 1 ): 1663 ( CO, asym). Anal. Calcd. for C31H47BN4O2Na: C, 68.76; H, 8.75; N, 10.35. Found: C, 68.58; H, 8.56; N, 10.39. S14

Figure S32. 1 H NMR spectrum of [(Me 6TREN)Na][HCO 2BPh 3] in THF-d 8. Figure S33. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)Na][HCO 2BPh 3] in THF-d 8. Figure S34. 11 B NMR spectrum of [(Me 6TREN)Na][HCO 2BPh 3] in THF-d 8. S15

wave number (cm 1 ) Figure S35. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)Na][HCO 2BPh 3]. [(Me6TREN)K][HCO2BPh3] (9). A solution of [(Me6TREN)K][HBPh3] (0.100 mg, 0.195 mmol) in 2 ml of THF in a 25 ml Schlenk tube was degassed following three cycles of freeze-pump-thaw. The head space of the flask was then filled with CO2 (1 atm). After 30 min, all volatiles were removed under vacuum and the residue was washed with n-pentane (3 x 5 ml). After 30 min, all volatiles were removed under vacuum and the residue was washed with n-pentane (3 x 5 ml). Drying under vacuum afforded analytically pure [(Me6TREN)K][HCO2BPh3] (15, 0.091 g, 0.164 mmol, 84%) as a white powder. X-ray quality single crystals were obtained from a concentrated 1 H NMR (400 MHz, THF-d8): δ 8.32 (s, 1H, OCHO), 7.25 (m, 6 H, o-aryl), 7.00 (m, 6H, m-aryl), 6.90 (m, 3H, p-aryl), 2.54 (m, 6 H, CH2), 2.30 (m, 6 H, CH2), 2.15 (s, 18 H, NMe2). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 170.7 (OCHO), 157.8 (ipso-aryl), 134.7 (o-aryl), 127.0 (m-aryl), 124.5 (p-aryl), 59.3 (CH2), 54.6 (CH2), 46.4 (NMe2). 11 B NMR (128 MHz, THF-d8): δ 4.1 (br). IR (KBr, cm 1 ): 1677 ( CO, asym). Anal. Calcd. for C31H47BN4O2K: C, 66.77; H, 8.50; N, 10.05. Found: C, 66.46; H, 8.33; N, 10.22. S16

Figure S36. 1 H NMR spectrum of [(Me 6TREN)K][HCO 2BPh 3] in THF-d 8. Figure S37. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)K][HCO 2BPh 3] in THF-d 8. Figure S38. 11 B NMR spectrum of [(Me 6TREN)K][HCO 2BPh 3)] in THF-d 8. wave number (cm 1 ) Figure S39. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)K][HCO 2BPh 3]. S17

[(Me6TREN)Li][HB(C6F5)3] (10) A solution of B(C6F5)3 (0.084 g, 0.164 mmol) in 2 ml of THF was added dropwise to a solution of [(Me6TREN)Li][N(SiHMe2)2] (0.060 g, 0.162 mmol) in 1 ml of THF. The resulting mixture was stirred for 2 h at room temperature. The solution was then evaporated to dryness under reduced pressure to obtain an oily residue. Addition of n-pentane (5 ml) precipitated a white solid, which was further washed with fresh n-pentane (3 x 2 ml) and dried under vacuum to obtain analytically pure [(Me6TREN)Li][HB(C6F5)3] (10, 0.105 g, 0.140 mmol, 86% yield) as a white powder. 1 H NMR (THF-d8, 400 MHz): δ 3.71 (br, q, 1 H, HB), 2.57 (m, 6 H, CH2), 2.40 (m, 6 H, CH2), 2.23 (s, 18 H, NMe2). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 150.6 (aryl), 148.2 (aryl), 139.9 (aryl), 138.6 (aryl), 137.5 (aryl), 136.1 (aryl), 58.7 (CH2), 52.7 (CH2), 46.3 (NMe2). 11 B{ 1 H} NMR (128 MHz, THF-d8): δ 25.3 (d, 1 JBH = 90 Hz). 19 F NMR (THF-d8, 377 MHz): δ 133.4, 166.6, 169.0. 7 Li{ 1 H} NMR (156 MHz, THF-d8): δ 2.2. IR (KBr, cm 1 ): 2401 ( BH). Anal. Calcd. for C30H31BF15N4Li: C, 48.02; H, 4.16; N, 7.47. Found: C, 47.89; H, 3.98; N, 7.28. Figure 40. 1 H NMR spectrum of [(Me 6TREN)Li][HB(C 6F 5) 3] in THF-d 8. S18

Figure S41. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)Li][HB(C 6F 5) 3] in THF-d 8. Figure 42. 11 B NMR spectrum of [(Me 6TREN)Li][HB(C 6F 5) 3] in THF-d 8. Figure S43. 19 F NMR spectrum of [(Me 6TREN)Li][HB(C 6F 5) 3] in a THF-d 8. S19

Figure S44. 7 Li{ 1 H} NMR spectrum of [(Me 6TREN)Li][HB(C 6F 5) 3] in a THF-d 8. wave number (cm 1 ) Figure S45. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)Li][HB(C 6F 5) 3]. [(Me6TREN)Na][HB(C6F5)3] (11) A solution of B(C6F5)3 (0.133 g, 0.260 mmol) in 2 ml of THF was added dropwise to a solution of [(Me6TREN)Na][N(SiHMe2)2] (0.100 g, 0.259 mmol) in 1 ml of THF. The resulting mixture was stirred for 2 h at room temperature. The solution was then evaporated to dryness under reduced pressure to give an oily residue. Addition of n-pentane (5 ml) precipitated a white solid, which was further washed with fresh n-pentane (3 x 2 ml) and dried under vacuum to give analytically pure [(Me6TREN)Na][HB(C6F5)3] (10, 0.166 g, 0.217 mmol, 84% yield) as a white powder. 1 H NMR (THF-d8, 400 MHz): δ 3.72 (br, q, 1 H, HB), 2.54 (m, 6 H, CH2), 2.39 (m, 6 H, CH2), 2.23 (s, 18 H, NMe2). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 150.7 (aryl), 148.2 (aryl), 139.7 (aryl), 138.5 (aryl), 137.3 (aryl), 136.1 (aryl), 58.6 (CH2), 52.7 (CH2), 46.0 (NMe2). 11 B{ 1 H} NMR (128 MHz, THF-d8): δ 25.4 (d, 1 JBH = 93 Hz). 19 F NMR (THF-d8, 377 MHz): δ 133.4, 166.6, 169.0. IR (KBr, cm 1 ): 2374 ( BH). Anal. Calcd. for C30H31BF15N4Na: C, 47.02; H, 4.08; N, 7.31. Found: C, 46.90; H, 4.23; N, 7.19. Figure 46. 1 H NMR spectrum of [(Me 6TREN)Na][HB(C 6F 5) 3] in THF-d 8. S20

Figure S47. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)Na][HB(C 6F 5) 3] in THF-d 8. Figure 48. 11 B NMR spectrum of [(Me 6TREN)Na][HB(C 6F 5) 3] in THF-d 8. Figure S49. 19 F{ 1 H} NMR spectrum of [(Me 6TREN)Na][HB(C 6F 5) 3] in a THF-d 8. S21

wave number (cm 1 ) Figure S50. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)Na][HB(C 6F 5) 3]. [(Me6TREN)K][HB(C6F5)3] (12) A solution of B(C6F5)3 (0.067 g, 0.131 mmol) in 2 ml of THF was added dropwise to a solution of [(Me6TREN)K][N(SiHMe2)2] (0.052 g, 0.129 mmol) in 1 ml of THF. The resulting mixture was stirred for 2 h at room temperature. The solution was evaporated to dryness under reduced pressure to obtain an oily residue. Addition of n-pentane (5 ml) precipitated a white solid, which was further washed with fresh n-pentane (3 x 2 ml) and finally dried under vacuum to give analytically pure [(Me6TREN)K][HB(C6F5)3] (10, 0.090 g, 0.115 mmol, 89% yield) as a white powder. 1 H NMR (THF-d8, 400 MHz): δ 3.71 (br, q, 1 H, HB), 2.55 (m, 6 H, CH2), 2.30 (m, 6 H, CH2), 2.15 (s, 18 H, NMe2). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 150.6 (aryl), 148.2 (aryl), 139.8 (aryl), 138.6 (aryl), 137.5 (aryl), 136.1 (aryl), 59.4 (CH2), 54.6 (CH2), 46.4 (NMe2). 11 B{ 1 H} NMR (128 MHz, THF-d8): δ 25.5 (d, 1 JBH = 93 Hz). 19 F NMR (THF-d8, 377 MHz): δ 133.5, 166.7, 169.1. IR (KBr, cm 1 ): 2371 ( BH). Anal. Calcd. for C30H31BF15N4K: C, 46.05; H, 3.99; N, 7.16. Found: C, 46.33; H, 3.80; N, 7.09. Figure S51. 1 H NMR spectrum of [(Me 6TREN)K][HB(C 6F 5) 3] in THF-d 8. S22

Figure S52. 13 C{ 1 H} NMR spectrum of [(Me 6TREN)K][HB(C 6F 5) 3] in THF-d 8. Figure S53. 11 B{ 1 H} NMR spectrum of [(Me 6TREN)K][HB(C 6F 5) 3] in THF-d 8. Figure S54. 19 F{ 1 H} NMR spectrum of [(Me 6TREN)K][HB(C 6F 5) 3] in THF-d 8. S23

wave number (cm 1 ) Figure S55. Solid-state IR (KBr pellet) spectrum of [(Me 6TREN)K][HB(C 6F 5) 3]. In situ characterization of [(Me6TREN)M][Ph3B OR] (M = Li, R = CHPh2; M = K, R = CH2Ph). Carbonyls were readily inserted into the B-H bonds of 4-6. This is exemplified by in situ spectroscopic characterizations of alkoxyborates resulting from 4 and 6 in reactions with Ph2CO and PhCHO respectively. [(Me6TREN)Li][Ph3B OCHPh2]. Figure S56. 1 H NMR spectrum of [(Me 6TREN)Li][Ph 3B OCHPh 2] in THF-d 8. S24

Figure S57. 13 C NMR spectrum of [(Me 6TREN)Li][Ph 3B OCHPh 2] in THF-d 8. Figure S58. 11 B NMR spectrum of [(Me 6TREN)Li][Ph 3B OCHPh 2] in THF-d 8. [(Me6TREN)K][Ph3B OCH2Ph]. Figure S59. 1 H NMR spectrum of [(Me 6TREN)K][Ph 3B OCH 2Ph] in THF-d 8. S25

Figure S60. 13 C NMR spectrum of [(Me 6TREN)K][Ph 3B OCH 2Ph] in THF-d 8. Figure S61. 11 B NMR spectrum of [(Me 6TREN)K][Ph 3B OCH 2Ph] in THF-d 8. Synthesis and Characterization of [ n Bu4N][HBPh3]. A THF solution of K[HBPh3] (0.061 g, 0.216 mmol) and n Bu4NI (0.080 g, 0.216 mmol) were stirred at room temperature for 2 h to give a milky white suspension. It was filtered and the filtrate was evaporated under reduced pressure to give [ n Bu4N][HBPh3] (0.096 g, 0.198 mmol, 92%) as a colorless powder. 1 H NMR (400 MHz, THF-d8): δ 7.30 (m, 6 H, o-aryl), 6.89 (m, 6 H, m-aryl), 6.72 (m, 3 H, p-aryl), 3.50 (br, q, 1 H, HB), 2.88 (m, 8 H, NCH2CH2CH2CH3), 1.42 (m, 8 H, NCH2CH2CH2CH3), 1.28 (m, 8 H, NCH2CH2CH2CH3), 0.94 (m, 12 H, NCH2CH2CH2CH3). 13 C{ 1 H} NMR (100 MHz, THF-d8): δ 165.6 (ipso-aryl), 136.7 (o-aryl), 126.4 (m-aryl), 122.2 (p-aryl), 59.2 (NCH2CH2CH2CH3), 24.8 (NCH2CH2CH2CH3), 20.7 (NCH2CH2CH2CH3), 14.2 (NCH2CH2CH2CH3). 11 B NMR (128 MHz, THF-d8): δ 8.0 (d, 1 JBH = 78 Hz). Anal. Calcd. for C34H52BN: C, 84.10; H, 10.89; N, 2.88. Found: C, 83.80; H, 10.68; N, 2.82. S26

Figure S62. 1 H NMR spectrum of [( n Bu) 4N]][HBPh 3] in THF-d 8. Figure S63. 13 C NMR spectrum of [( n Bu) 4N][HBPh 3] in THF-d 8. Figure S64. 11 B NMR spectrum of [( n Bu) 4N][HBPh 3] in THF-d 8. S27

Catalysis. Typical NMR-scale catalytic hydroboration of carbonyls using HBpin. A J.Young-style NMR tube was charged with substrate (0.27 mmol), HBpin (0.27 mmol), and 0.5 ml of a 2:1 mixture of THF and THF-d8. Desired catalyst loading was achieved by adding an appropriate volume of THF-d8 stock solution of catalyst of known concentration using a microliter syringe. Reaction progress was monitored at room temperature using NMR spectroscopy. The products were characterized by 1 H, 11 B, and 13 C NMR spectroscopies and compared with the literature. For a selected number of substrates, 1 H NMR spectra of the catalytic reaction mixture are provided below to show the completion of reduction. S28

S29

S30

Figure S65-73. 1 H NMR spectra of the catalytic reaction mixture for a selected number of substrates. Catalytic hydroboration of benzophenone on mmol scale. A 20 ml screw-cap vial fitted with a magnetic stir bar was charged with Ph2CO (500 mg, 2.74 mmol), HBpin (350 mg, 2.74 mmol), 4 (1 mg, 2 mol) and 2 ml of THF. The resulting reaction mixture was stirred for 1 h at room temperature. It was filtered through a plug of silica. All the volatiles were then removed to give Ph2CHOH (485 mg, 2.63 mmol, 96%) as a colorless crystalline solid. The product was characterized by 1 H and 13 C{ 1 H} NMR and FT-IR spectroscopy. Mp.: 66-68 C (lit. 69 C). Figure S74. 1 H NMR spectrum of Ph 2CHOH synthesized on mmol scale by reducing Ph 2CO. S31

Figure S75. 13 C{ 1 H} NMR spectrum of Ph 2CHOH synthesized on mmol scale by reducing Ph 2CO. Figure S76. Solid-state IR (KBr pellet) spectrum of Ph 2CHOH synthesized on mmol scale by reducing Ph 2CO. Typical NMR-scale catalytic hydroboration of CO2 using HBpin. A J.Young-style NMR tube was charged with HBpin (0.27 mmol) and 500 L of THF-d8. Desired catalyst loading was achieved by adding an appropriate volume of THF-d8 stock solution of catalyst of known concentration using a microliter syringe. Initial 1 H NMR spectrum of this mixture was acquired before subjecting it to three freeze-pump-thaw cycles, followed by filling the headspace of the tube with 1 bar of CO2. Reaction progress was monitored at room S32

temperature from time to time using NMR spectroscopy. The product pinb-o2ch was characterized by 1 H, 11 B, and 13 C NMR spectroscopies and compared with the literature. S5 Figure S77. 1 H NMR spectrum of pinb O 2CH from the catalytic reaction mixture. Figure S78. 11 B NMR spectrum of pinb O 2CH from the catalytic reaction mixture. S33

Figure S79. 13 C NMR spectrum of pinb O 2CH from the catalytic reaction mixture. NMR spectra of 1:3.5 mixture of 4 and HBpin. Figure S80. 1 H NMR spectrum of a 1:3.5 mixture of 4 and HBpin in THF-d 8. S34

Figure S81. 11 B NMR spectrum of a 1:3.5 mixture of 4 and HBpin in THF-d 8. Single Crystal X-ray diffraction Single-crystal X-ray diffraction measurements were performed on a Bruker AXS diffractometer equipped with an Incoatec microsource and an APEX area detector using MoK radiation, multilayer optics and -scans. Experimental parameters and refinement results are given in Table S1. The data reductions were performed with the Bruker SAINT software. S6a Absorption corrections were carried out using the program SADABS. S6b The structures were solved by direct methods using the program SIR-92. S6c Compound 4 was found with three crystallographically independent molecules and compound 8 with two crystallographically independent molecules in the crystal lattice. Compound 7 shows crystallographic C3 symmetry in space group P3 with the atoms B1, Li1 and N4 on the crystallographic axis. The crystallographically imposed symmetry leads to disorder of the central CO2H fragment (atoms C1, O1 and O2) that could be modelled. All refinements were carried out by the full-matrix least squares method using SHELXL-2013 as implemented in the WinGX program system with anisotropic displacement parameters for all non-hydrogen atoms. S6d,e Hydrogen atoms were included in calculated positions with isotropic displacement parameters and treated as riding. Only the hydrogen atoms bound to the boron atoms in 4 (H1, H2 and H3), all hydrogen atoms in 6, in 7 as well as the hydrogen atom bound to the boron atom in 9 (H1) were refined in their position. Due to disorder, split positions were introduced for the atoms C39, C40 and C43 within the Me6TREN ligand as well as for the carbon atoms of one coordinated thf ligand in 4 (C47 C50). Split positions were also introduced for carbon atoms within one Me6TREN ligand (C2 C8 and C11 C13) as well as for the carbon and oxygen atoms within one central CO2H fragment (C32, O3 and O4) in 8. Compound 8 was refined as a two component twin using the twin law 1 0 0-1 -1 0-1 0-1 (BASF 0.12453). All reflections were used in the refinement, except for the reflections 1 0 0 in 6, 0 0 1 in 7 as well as 1 0 0 in 8 because they were most likely affected by the beamstop. Graphical representations were obtained with the computer program DIAMOND. S6f CCDC-1485148 (4), -1485149 (6), -1485150 (7), -1485151 (8), - 1485152 (9) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from the Crystallographic Data Centre via www.ccdc.cam.ac.uk/dada_request/cif. S35

Table S1. Crystal Data and Structure Refinement. chemical formula 4 6 7 8 9 C 16H 38LiN 4O, C 18H 16B C 30H 46BKN 4 C 31H 46BLiN 4O 2 C 31H 46BN 4NaO 2 C 31H 46BKN 4O 2 fw (g mol -1 ) 552.56 512.62 524.47 540.52 556.63 space group P1 P2 1/c P3 P1 P2 1/c unit cell parameters a (Å) 11.970(2) 16.436(7) 11.660(5) 13.3224(13) 9.570(2) b (Å) 12.2978(2) 10.063(4) 11.660(5) 17.0500(17) 19.486(4) c (Å) 17.763(2) 18.000(8) 13.306(5) 17.6861(18) 17.762(4) ( ) 80.063(5) 99.8463(17) ( ) 76.452(5) 91.481(8) 111.9899(17) 102.244(4) ( ) 82.123(6) 112.8622(16) V (Å 3 ) 2491.0(7) 2976(2) 1566.7(15) 3188.3(6) 3236.9(12) Z 3 4 2 4 4 T (K) 100(2) 100(2) 110(2) 100(2) 100(2) (Mo K ) (mm -1 ) 0.066 0.203 0.069 0.082 0.196 reflns 28677 32211 12181 31707 27023 independent reflns (Rint.) observed reflns goodness of fit on F 2 final R indices R1, wr2 [I 2 (I)] R1, wr2 (all data) 18273 (0.1646) 5468 (0.1081) 1939 (0.1078) 14640 (0.1015) 5974 (0.0882) 9974 3632 1112 9345 3835 1.016 1.073 1.074 1.074 1.037 0.0873, 0.1739 0.0747, 0.1630 0.0755, 0.1910 0.0732,0.1892 0.0585, 0.1218 0.1638, 0.2179 0.1156, 0.1813 0.1271, 0.2199 0.1111, 02145 0.1024, 0.1410 References (S1) Eppinger, J.; Herdtweck, E.; Anwander, R. Polyhedron 1998, 17, 1195. (S2) Britovsek, G. J. P.; England, J.; White, A. J. P. Inorg. Chem. 2005, 44, 8125. (S3) Massey, A. G.; Park, A. J. J. Organomet. Chem. 1964, 2, 245. (S4) Burlitch, J. M.; Burk, J. H.; Leonowicz, M. E.; Hughes, R. E. Inorg. Chem. 1979, 18, 1702. (S5) (a) Shintani, R.; Nozaki, K. Organometallics 2013, 32, 2459. (b) Suh, H.-W.; Guard, L. M.; Hazari, N. Chem. Sci. 2014, 5, 3859. (S6) (a) Bruker, SAINT-Plus, Bruker AXS Inc., Madison, Wisconsin, USA, 1999; (b) Bruker, SADABS, Bruker AXS Inc. Madison, Wisconsion, USA, 2004; (c) Altomare, A; Cascarano, G.; Giacovazzo, C.; Guagliardi, A. J. Appl. Crystallogr. 1993, 26, 343-350; (d) Sheldrick, G. M. Acta Crystallogr. Sect. A 2008, 64, 112-122; (e) Farrugia, L. J. J. Appl. S36

Crystallogr. 1999, 32, 837-838; (f) Brandenburg, K. Diamond Version 3.2i, Crystal Impact GbR, Bonn, 2012. S37