Synthesis of chiral polydentate ligands and the use of their titanium complexes as pre-catalysts for the asymmetric trimethylsilylcyanation of benzaldehyde

• DOI: 10.1007/s11172-008-0266-6
• Publication Date: 2009-08-04T04:30:50Z
• Authors: Yu. N. Belokon; D. A. Chusov; T. V. Skrupskaya; D. A. Bor’kin; L. V. Yashkina; K. A. Lyssenko; M. M. Il’in; T. V. Strelkova; G. I. Timofeeva; A. S. Peregudov; M. North
• Keywords: 01 natural sciences; 0104 chemical sciences

A number of polydentate ligands based on enantiomerically pure binaphthol have been synthesized. The ligand complexes with titanium isopropoxide were used as catalysts for the asymmetric addition of trimethylsilyl cyanide to benzaldehyde. A fragment with axial chirality is responsible for the configuration of O-trimethylsilyl cyanohydrin product. In the case of the optimum ligand based on (R)-binaphthol and (S)-leucinol, an enantiomeric excess of 86% and quantitative yield were achieved in 4 h.