Catalytic [5 + 1]-Cycloadditions of Vinylcyclopropanes and Vinylidenes
作者:Conner M. Farley、Kohei Sasakura、You-Yun Zhou、Vibha V. Kanale、Christopher Uyeda
DOI:10.1021/jacs.0c00356
日期:2020.3.11
1]-cycloaddition between a vinylcyclopropane and a vinylidene to provide methylenecyclohexenes bearing all-meta relationships. Vinylidene equivalents are generated from 1,1-dichloroalkenes using Zn as a stoichiometric reductant. Experimental observations are consistent with a mechanism involving a cobaltacyclobutane formed from a [2 + 2]-cycloaddition between a cobalt vinylidene and a vinylcyclopropane.
Ring-Opening Reaction of Methylenecyclopropanes Derived from Methylenecyclopropyl Aldehydes through Cope Rearrangement
作者:Xiang-Ying Tang、Yin Wei、Min Shi
DOI:10.1002/ejoc.201000880
日期:2010.11
Tandem Wittig reaction/Cope rearrangement of methylenecyclopropyl aldehydes 1 with cinnamyltriphenylphosphonium bromide afforded a convenient method for the synthesis of cyclopentene derivatives 2 in moderate yields in a one-pot manner. Dialkyl 2-[(2-methylenecyclopropyl)methylene]malonates 3 derived from methylenecyclopropyl aldehydes 1 could produce two kinds of cyclopentene derivatives, 4 and 5
Organo-Selenium Induced Radical Ring-Opening Intramolecular Cyclization or Electrophilic Cyclization of 2- (Arylmethylene)cyclopropylaldehyde: A Tunable Synthesis of 1-Naphthaldehydes or 3-Oxabicyclo[3.1.0]hexan-2-ols
作者:Maozhong Miao、Xian Huang
DOI:10.1021/jo900805a
日期:2009.8.7
1-Naphthaldehydes and 3-oxabicyclo[3.1.0]hexan-2-ols can be prepared, respectively, by the intramolecular alkylation and cyclization of (E)-2-(arylmethylene)cyclopropylaldehyde 1 mediated by different organo-selenium reagents. The properties of selenium reagents may play an important role in the reactions. A rationale for these transformations is proposed.
Substrate-Controlled Selective Proximal and Distal C−C Bond Cleavage via Lewis Acid Mediated O-Acylation of 2-(Arylmethylene)cyclopropylaldehyde: A Stereoselective Synthesis of Bifunctional Methylenecyclobutanes and 1,3-Conjugated Dienes
作者:Xian Huang、Maozhong Miao
DOI:10.1021/jo801021f
日期:2008.9.1
ZnCl2-mediated reactions of (E)-2-(arylmethylene)cyclopropylaldehyde 1 with various acylchlorides provide a novel method for stereoselective synthesis of bifunctional methlylenecyclobutanes via a proximal-bond cleavage process. Nevertheless, when (Z)-1 was employed, the reactions give 1,3-conjugated dienes through distal-bond cleavage.
Palladium-Catalyzed Reactions of 3-Substituted Methylenecyclopropanes
作者:Li-Xiong Shao、Jia Li、Bao-Yu Wang、Min Shi
DOI:10.1002/ejoc.201001082
日期:2010.11
Pd-catalyzed reactions of 3-substitutedmethylenecyclopropanes (MCPs), in which the substituents can be either hydroxymethyl or formyl, have been thoroughly investigated in the presence or absence of an acid source. It was found that the Pd-catalyzed reactions of methylenecyclopropylcarbinols (Z)-1 in the presence of acetic acid, acetic acid 2-methylene-but-3-enyl esters 4 can be formed in moderate