Synthesis of 3,4-disubstituted piperidines by ene cyclisation of 4-aza-1,7-dienes
摘要:
Ene cyclisation of a variety of 4-aza-1,7-dienes affords 3,4-disubstituted piperidines. In particular, cyclisation of diesters 14 and 20 catalysed by MeAlCl2 gives the corresponding trans 3,4-disubstituted piperidines with diastereomeric ratios of > 200:1. (c) 2005 Elsevier Ltd. All rights reserved.
Synthesis of 3,4-disubstituted piperidines by ene cyclisation of 4-aza-1,7-dienes
作者:Stephen M. Walker、Jodi T. Williams、Alexander G. Russell、John S. Snaith
DOI:10.1016/j.tetlet.2005.08.002
日期:2005.9
Ene cyclisation of a variety of 4-aza-1,7-dienes affords 3,4-disubstituted piperidines. In particular, cyclisation of diesters 14 and 20 catalysed by MeAlCl2 gives the corresponding trans 3,4-disubstituted piperidines with diastereomeric ratios of > 200:1. (c) 2005 Elsevier Ltd. All rights reserved.
Stereoselective synthesis of 3,4-disubstituted and 3,4,5-trisubstituted piperidines by Lewis acid-catalysed ene cyclisation of 4-aza-1,7-dienes
作者:Stephen M. Walker、Jodi T. Williams、Alexander G. Russell、Benson M. Kariuki、John S. Snaith
DOI:10.1039/b708139a
日期:——
there was a fine balance between the desired ene cyclisation and the competing hetero-Diels-Alder reaction, with the product distribution being influenced by the activating group on the enophile, the nature of the ene component, and the Lewis acid used. Activation of the enophile with an oxazolidinone function facilitated Lewis acid-catalysedcyclisation to afford mixtures of ene and hetero-Diels-Alder