Ring-closing iodoamination of homoallylic amines for the synthesis of聽polysubstituted pyrrolidines: application to the asymmetric synthesis of (鈭?-codonopsinine

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• 作者：Stephen G. Davies ; ^{steve.davies@chem.ox.ac.uk} ; James A. Lee ; Paul M. Roberts ; James E. Thomson ; Callum J. West
• 关键词：(&minus ; )-Codonopsinine ; Lithium amide ; Ring-closing iodoamination ; Pyrrolidine
• 刊名：Tetrahedron
• 出版年：2012
• 期刊代码：107_00404020
• 类别：ch
• 出版时间：3 June, 2012
• 卷：68
• 期：22
• 页码：4302-4319
• 文件大小：2203 K

摘要

Ring-closing iodoamination of (E)-configured, N-伪-methyl-p-methoxybenzyl protected homoallylic amines upon treatment with I₂ and NaHCO₃ in MeCN occurs with concomitant loss of the N-伪-methyl-p-methoxybenzyl group to give 3-iodopyrrolidines in >99:1 dr. This transformation was used as one of the key steps in the total asymmetric synthesis of (鈭?-codonopsinine, which was achieved in seven steps (from commercially available tert-butyl crotonate) in 5%overall yield and >99:1 dr.