Pure Appl. Chem., 2008, Vol. 80, No. 4, pp. 687-694
doi:10.1351/pac200880040687
Stereoselectivity of the Petasis reaction with various chiral amines and styrenylboronic acids*
Quentin I. Churches1, Helen E. Stewart2, Scott B. Cohen2, Adam Shröder1, Peter Turner2, and Craig A. Hutton1
1School of Chemistry and Bio21 Institute of Molecular Science and Biotechnology, The University of Melbourne, VIC 3010, Australia; 2School of Chemistry, The University of Sydney, NSW 2006, Australia
Abstract:
Several chiral amines were investigated for the stereoselective preparation of homophenylalanine derivatives using the Petasis reaction. Chiral secondary amines such as N,α-dimethylbenzylamine and N-benzylphenylglycinol gave the best results in terms of both yield and diastereoselectivity. The use of N-benzylphenylglycinol leads directly to 3-alkenyl-4-benzyl-5-phenyloxazin-2-one products. Intriguing variation was observed in the stereoselectivity of reactions employing para-substituted styrenylboronic acid substrates, where presumably only electronic factors are involved.
Keywords: amino acids; boronic acids; multicomponent coupling; Petasis reaction; stereoselective.
*Paper based on a presentation at the 21st International Congress for Heterocyclic Chemistry (ICHC 21), 15-20 July 2007, Sydney, Australia. Other presentations are published in this issue, pp. 669-805.