Stereoselective synthesis of 2,3-unsaturated O-aryl glycosides from glycals using Tris(pentafluorophenyl)borane as
Sankar Sau1, Nishant Mishra1, Anjali Aghi1
1Department of Chemistry, Indian Institute of Technology Patna, Bihta, Bihar, 801106, India.
Abstract:
Herein, we report the stereoselective synthesis of 2,3-unsaturated α-O-aryl glycosides from disarmed glycals and challenging phenol as glycosyl acceptors using tris(pentafluorophenyl)borane (BCF) as an optimal catalyst. The optimized reaction conditions operate under metal-free conditions, affording the valuable 2,3-unsaturated-O-aryl glycosides in good to excellent yields with exclusive α-anomeric selectivity. The BCF catalyst not only activates the disarmed glycal donors but also enhances the nucleophilicity of electronically challenging phenol acceptors. A diverse range of glycosyl donors and acceptors were explored, and the method was further extended for scale-up synthesis and subsequent synthetic derivatization.
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