Homoallyllic Nitrone Isomerization: Convenient Enantioselective Synthesis of Homoallylic Nitrones and Homoallylic Hydroxylamines
摘要:
An alpha-regioselective synthesis of homoallylic nitrones from aldehydes is reported on the basis of [3,3]-sigmatropic rearrangement. The products are obtained in up to 99% enantioselectivity and up to 80% yield under environmentally benign and mild reaction conditions.
作者:Guohua Hou、Francis Gosselin、Wei Li、J. Christopher McWilliams、Yongkui Sun、Mark Weisel、Paul D. O’Shea、Cheng-yi Chen、Ian W. Davies、Xumu Zhang
DOI:10.1021/ja903319r
日期:2009.7.29
N-H ketoimines 3a-3v are readily prepared in high yield via organometallic addition to nitrites and isolated as corresponding bench-stable hydrochloride salts. Homogeneous asymmetric hydrogenation of unprotected N-H ketoimines 3a-3v using Ir-(S,S)-f binaphane as catalyst provides chiral amines 4a-4v in 90-95% yield with enantioselectivities up to 95% ee.