Gold(I) Catalyzed Isomerization of 5-en-2-yn-1-yl Acetates: An Efficient Access to Acetoxy Bicyclo[3.1.0]hexenes and 2-Cycloalken-1-ones
摘要:
The gold(I) catalyzed rearrangement of 5-en-2-yn-1-yl acetates into functionalized acetoxy bicyclo[3.1.0]hexenes is described. The mild reaction conditions employed allow the efficient and rapid synthesis of a variety of such bicyclic compounds via a sequence of two gold(I)-catalyzed isomerization steps. Acetoxy bicyclo[3.1.0]hexenes products can be further transformed to 2-cycloalkenones by simple methanolysis.
Terminal allylicalcohols are important motifs in natural products, and also key intermediates/precursors in numerous novel reaction transformations. In this study, enabled by a bifunctional ligand featuring a basic amino group, a gold-catalyzed hydroarylation of terminal unactivated propargylic alcohols with heteroareneboronic acids has been first established, and efficiently affords various terminal
Novozym-435-catalyzed enzymatic separation of racemic propargylic alcohols. A facile route to optically active terminal aryl propargylic alcohols
作者:Daiwang Xu、Zuyi Li、Shengming Ma
DOI:10.1016/s0040-4039(03)01528-4
日期:2003.8
Novozym-435 (a form of Candida antarctica lipase B) was found to be an effective biocatalyst for the kinetic resolution of a variety of racemic terminal aryl propargylic alcohols affording highly optically active (S)-propargylic alcohols and (R)-propargylic alcohol acetates in high yields and good ees. The advantages of this reaction are the easy availability of starting materials and the biocatalyst, simple reaction conditions, easy operation and high stereoselectivity. (C) 2003 Published by Elsevier Ltd.