Mechanism of enantioselective Ti-catalyzed Strecker reaction: peptide-based metal complexes as bifunctional catalysts

…, KW Kuntz, ML Snapper, AH Hoveyda

Index: Degrado; Mizutani; Hoveyda Journal of the American Chemical Society, 2001 , vol. 123, # 4 p. 755 - 756

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Citation Number: 121

Abstract

Kinetic, structural, and stereochemical data regarding the mechanism of Ti-catalyzed addition of cyanide to imines in the presence of Schiff base peptide ligands are disclosed. The reaction is first order in the Ti⊙ ligand complex; kinetic studies reveal ΔS⧧=-45.6±4.1 cal K-1 mol-1, indicating a highly organized transition structure for the turnover-limiting step of the catalytic cycle. A mechanistic model consistent with the kinetic and stereochemical ...