(1R,2R)-N,N′-Bis[o-(diphenylphosphino)benzyl]cyclohexane-1,2-diamine, (1S,2S)-N,N′-Bis[o-(diphenylphosphino)benzyl]cyclohexane-1,2-diamine

[174758-63-5] C44H44N2P2 (MW 662.78) InChI = 1S/C44H44N2P2/c1-5-21-37(22-6-1)47(38-23-7-2-8-24-38)43-31-17-13-19-35(43)33-45-41-29-15-16-30-42(41)46-34-36-20-14-18-32-44(36)48(39-25-9-3-10-26-39)40-27-11-4-12-28-40/h1-14,17-28,31-32,41-42,45-46H,15-16,29-30,33-34H2/t41-,42-/m1/s1 InChIKey = OBHPYVNBXWUKNY-NCRNUEESSA-N [174677-83-9] C44H44N2P2 (MW 662.78) InChI = 1S/C44H44N2P2/c1-5-21-37(22-6-1)47(38-23-7-2-8-24-38)43-31-17-13-19-35(43)33-45-41-29-15-16-30-42(41)46-34-36-20-14-18-32-44(36)48(39-25-9-3-10-26-39)40-27-11-4-12-28-40/h1-14,17-28,31-32,41-42,45-46H,15-16,29-30,33-34H2/t41-,42-/m0/s1 InChIKey = OBHPYVNBXWUKNY-COCZKOEFSA-N (chiral ligand for transition metal-catalyzed asymmetric reactions, including transfer hydrogenation of ketones, kinetic resolution of racemic secondary alcohols, and oxidation of olefins1) Alternate Names: (R,R)-C6P2(NH)2, (S,S)-C6P2(NH)2; (S,S)-N,N′-bis[o-(diphenylphosphino)benzyl]-1,2-diaminocyclohexane, (R,R)-N,N′-bis[o-(diphenylphosphino)benzyl]-1,2-diaminocyclohexane; N,N′-bis[o-(diphenylphosphino)benzylidene]-lR,2R-diaminocyclohexane, N,N′-bis[o-(diphenylphosphino)benzylidene]-lS,2S-diaminocyclohexane. Physical Data: cream-white crystals, mp 54–56 °C, [α]D20 = −29.23 (c 1, CH2Cl2). Solubility: soluble in chlorinated solvents, acetone, warm EtOH; hard to dissolve in water and insoluble hexane. Analysis of Reagent Purity: 1H NMR (500 MHz, CDCl3): δ 6.81–7.52 (m, 28H), 4.00 (d, 2H, J = 13.6 Hz), 3.82 (d, 2H, J = 12.8 Hz), 1.87 (br, 2H), 1.58 (d, 2 H, J = 6.4 Hz), 1.08 (t, 2H), 0.87 (m, 2H); 31P NMR (500 MHz, CDCl3): δ −15.21. Preparative Methods: both enantiomers are readily prepared by the reduction of (R,R)- or (S,S)-N,N′-bis[o-(diphenylphosphino)benzylidene]-1,2-diiminocyclohexane with NaBH4 in absolute EtOH, respectively.2, 3 Handling, Storage, and Precautions: no special instructions for storage and handling are mentioned in the literature. In general, they are stable at ambient temperature; for longer periods, storage in refrigerator is recommended; generally considered low mammalian toxicity, however, thorough toxicity studies have not been performed; skin/eye contact should be avoided. Purification: the ligand can be purified by crystallization with CH2Cl2/EtOH.