Asymmetric Ring Opening of meso-Epoxides with Aromatic Amines Catalyzed by a New Proline-Based N,N′-Dioxide-Indium Tris(triflate) Complex

✍ Scribed by Bo Gao; Yuehong Wen; Zhigang Yang; Xiao Huang; Xiaohua Liu; Xiaoming Feng

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 242 KB
• Volume: 350
• Category: Article
• ISSN: 1615-4150
• DOI: 10.1002/adsc.200700474

✦ Synopsis

Abstract

The catalytic asymmetric ring opening of meso‐epoxides with aromatic amines was achieved using a new proline‐based N,N′‐dioxide‐indium tris(triflate) complex in high yields (up to 99%) with excellent enantioselectivities (up to 99% ee) under mild conditions. The coordination ability of N,N′‐dioxide 1c was investigated by X‐ray and NMR analysis. A plausible seven‐coordinate transition state model was proposed. The chiral N,N′‐dioxides surveyed were synthesized from proline through only three conventional steps. The procedure could be run on a gram‐scale without any loss of enantioselectivity. This protocol provides a highly practical and useful tool for the bulky preparation of optically pure β‐amino alcohols.