[2+2] Cycloaddition of 1,3-Dienes by Visible Light Photocatalysis
作者:Anna E. Hurtley、Zhan Lu、Tehshik P. Yoon
DOI:10.1002/anie.201405359
日期:2014.8.18
[2+2] Photocycloadditions of 1,3‐dienes represent a powerful yet synthetically underutilized class of reactions. We report that visiblelight absorbing transition metal complexes enable the [2+2] cycloaddition of a diverse range of 1,3‐dienes. The ability to use long‐wavelength visiblelight is attractive because these reaction conditions tolerate the presence of sensitive functional groups that might
Catalytic Asymmetric [4+2]-Cycloaddition of Dienes with Aldehydes
作者:Luping Liu、Hyejin Kim、Youwei Xie、Christophe Farès、Philip S. J. Kaib、Richard Goddard、Benjamin List
DOI:10.1021/jacs.7b08357
日期:2017.10.4
Despite its significant potential, a general catalytic asymmetric [4+2]-cycloaddition of simple and electronically unbiased dienes with any type of aldehyde has long been unknown. Previously developed methodologies invariably require activated, electronically engineered substrates. We now provide a general solution to this problem. We show that highly acidic and confined imidodiphosphorimidates (IDPis)
The awesome power of metathesis is illustrated by a concise synthesis of the extremely scarce marine natural product amphidinolide V, which hinges on a sequence of ring‐closing alkynemetathesis followed by intermolecular enynemetathesis with ethylene (see scheme). As a complete set of conceivable stereoisomers was prepared, the constitution and absolute configuration of this macrolide could be established
Development of a Formal [4 + 1] Cycloaddition: Pd(OAc)<sub>2</sub>-Catalyzed Intramolecular Cyclopropanation of 1,3-Dienyl β-Keto Esters and MgI<sub>2</sub>-Promoted Vinylcyclopropane−Cyclopentene Rearrangement
作者:Rockford W. Coscia、Tristan H. Lambert
DOI:10.1021/ja809226x
日期:2009.2.25
A formal [4 + 1] cycloaddition of 1,3-dienyl beta-keto esters has been developed. This two step process involves Pd(II)-catalyzed intramolecular cyclopropanation to produce vinylcyclopropanes and a subsequent mild vinylcyclopropane-cyclopentene rearrangement promoted by MgI(2). The cyclopropanation method notably requires the use of Mg(ClO(4))(2), presumably to facilitate keto-enol tautomerization