Isothiourea-catalysed chemo- and enantioselective [2,3]-sigmatropic rearrangements of N,N-diallyl allylic ammonium ylides

TETRAHEDRON

卷:73

Article

West, Thomas H.¹  Spoehrle, Stephanie S. M.¹  Smith, Andrew D.¹ 

[1] Univ St Andrews, Sch Chem, EaStCHEM, St Andrews KY16 9ST, Fife, Scotland

关键词: [23]-rearrangement;    Isothiourea catalysis;    Allylic ammonium ylides;    Enantioselective catalysis;    alpha-amino esters;   

DOI  :  10.1016/j.tet.2017.01.062

来源: Elsevier

【 摘 要 】

The isothiourea-catalysed chemo- and enantioselective [2,3]-sigmatropic rearrangement of N,N-diallyl allylic ammonium ylides is explored as a key part of a route to free functionalised alpha-amino esters and piperidines. The [2,3]-sigmatropic rearrangement proceeds with excellent diastereo- and enantiocontrol (>95:5 dr; up to 97% ee), with the resultant N,N-diallyl alpha-amino esters undergoing either mono- or bis-Nallyl deprotection. Bis-N-allyl deprotection leads to free alpha-amino esters, while the mono-deprotection strategy has been utilized in the synthesis of a target functionalised piperidine. (C) 2017 Published by Elsevier Ltd.

【 授权许可】

Free