type of structure units is full of challenge due to their congested chemical environment. Herein, we report a new gold(I) self-relay catalysis merging [3,3]-sigmatropic rearrangement/Nazarov cyclization with allylic alkylation starting from 1,3-enyne acetates and allylic alcohols, producing a wide range of synthetically important allyl cyclopentenones with an all-carbon quaternary stereocenter in good
A Recyclable Polystyrene-Supported Gold(I) Catalyst
作者:Wenjie Cao、Biao Yu
DOI:10.1002/adsc.201100133
日期:2011.8
A polystyrene-(benzotriazole)(triphenylphosphine)gold(I) [Btz⋅Au(I)PPh3] resin, representing the first polystyrene-immobilized homogeneous gold(I) complex, was conveniently prepared, and showed remarkable catalytic activities and recyclability in three model transformations, including the tandem 3,3-rearrangement and Nazarov reaction of an enynyl acetate, the cyclization of a 1,6-enyne, and the rearrangement
An efficientsynthetic approach for the synthesis of cyclopentenones containing a C–C stereocenter that relies on gold(I)-catalyzed Nazarov-type cyclization/1,6-addition of 1,3-enyne esters with p-quinone methides (p-QMs) is described. This tandem transformation exhibited a satisfactory substrate scope and passable functional group compatibility, providing a novel protocol for rapid assembly cyclopentenones
一种有效合成含有 C-C 立构中心的环戊烯酮的合成方法,该方法依赖于金 (I) 催化的纳扎罗夫型环化/1,3-烯炔酯与对醌甲基化物的 1,6-加成( p -QMs )进行了描述。这种串联转化表现出令人满意的底物范围和良好的官能团兼容性,为在温和反应条件下以良好至优异的产率快速组装环戊烯酮提供了新的方案。
Diastereoselective [4 + 1] Cycloaddition of Alkenyl Propargyl Acetates with CO Catalyzed by [RhCl(CO)<sub>2</sub>]<sub>2</sub>
作者:Wei Chen、Jia-Hui Tay、Xiao-Qi Yu、Lin Pu
DOI:10.1021/jo3009403
日期:2012.7.20
A class of alkenyl propargyl acetates, RCH(OAc)C CC(CH3)=CH2 (5), are found to undergo [4 + 1] cycloaddition with CO (1 atm) in the presence of [RhCl(CO)(2)](2) in refluxing 1,2-dichloroethane to give cyclopentenones (6) in good yields. It has been demonstrated that, when the R group of 5 is a phenyl group bearing o-electron-withdrawing substituents up to 10:1 diastereoselectivity and 96% yield can be achieved for the [4 + 1] cycloaddition. This process provides a convenient method to construct highly functionalized cyclopentenones that are useful in organic synthesis.