Highly Diastereoselective and Enantioselective Formal [4 + 3] Cycloaddition of Donor–Acceptor Cyclobutanes with Nitrones

• DOI: 10.1021/acs.orglett.5b01077
• Publication Date: 2015-05-14T12:33:43Z
• Authors: Jiang-Lin Hu; Lijia Wang; Hao Xu; Zuowei Xie; Yong Tang
• Keywords: Cyclobutanes; Nitrone

The first highly diastereoselective and enantioselective catalytic formal [4 + 3] cycloaddition of 1,1-cyclobutane diester with nitrone has been developed. Sterically hindered chiral SaBOX/Cu(II) complex promotes the reaction efficiently a broad substrate scope, producing range multifunctionalized optically active 1,2-oxazepanes excellent stereocontrol (up to >99/1 dr 97% ee).