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Letter

Structurally Well-Defined, Recoverable C₃-Symmetric Tris(β-hydroxy phosphoramide)-Catalyzed Enantioselective Borane Reduction of Ketones

Da-Ming Du,* Tao Fang, Jiaxi Xu, and Shi-Wei Zhang

Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China

Org. Lett., 2006, 8 (7), pp 1327–1330

DOI: 10.1021/ol0600584

Publication Date (Web): March 9, 2006

In papers with more than one author, the asterisk indicates the name of the author to whom inquiries about the paper should be addressed.

, dudm@pku.edu.cn

Abstract

A series of new chiral C₃-symmetric tris(β-hydroxy phosphoramide) ligands have been synthesized via the reaction of trisphosphoramide ester and Grignard reagents. The catalytic asymmetric borane reduction of ketones with these new C₃-symmetric chiral tris(β-hydroxy phosphoramide)s was investigated. Structurally well-defined, recoverable ligand 1d is an efficient catalyst for the enantioselective borane reduction of both electron-deficient and electron-rich ketones, and high enantioselectivities were achieved (up to 98% ee).

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