An efficient RhII -catalyzed synthesis of functionalized α-vinyl aldehydes with high E/Z stereoselectivity was developed. The reaction mediates the cyclopropanation of enaminones with vinyl carbenoids that are generated from cyclopropenes in situ to give the aminocyclopropane intermediates. Selective C-C bond cleavage of the cyclopropane intermediates leads to formation of α-vinyl aldehyde derivatives
Rh(II)-Catalyzed [2,3]-Sigmatropic Rearrangement of Sulfur Ylides Derived from Cyclopropenes and Sulfides
作者:Hang Zhang、Bo Wang、Heng Yi、Yan Zhang、Jianbo Wang
DOI:10.1021/acs.orglett.5b01542
日期:2015.7.2
Rh2(OAc)4-catalyzed [2,3]-sigmatropicrearrangement of sulfurylides is reported. A series of cyclopropenes were successfully employed for [2,3]-sigmatropicrearrangement by a reaction with either allylic or propargylic sulfides. Under the optimized conditions, the reaction afforded the products in moderate to excellent yields. In these transformations, the vinyl metal carbenes generated in situ from the cyclopropenes
Zinc-Catalyzed Alkene Cyclopropanation through Zinc Vinyl Carbenoids Generated from Cyclopropenes
作者:María J. González、Javier González、Luís A. López、Rubén Vicente
DOI:10.1002/anie.201505954
日期:2015.10.5
zinc‐catalyzed reaction of cyclopropenes with alkenes leading to vinylcyclopropane derivatives is reported. A broad range of alkenes (including highly substituted or functionalized alkenes) is compatible with this protocol. On the basis of trapping experiments and computational studies, this cyclopropanation reaction is proposed to proceed through initial formation of an electrophilic zinc vinyl carbenoid intermediate
Rhodium-Catalyzed Intermolecular Cyclopropanation of Benzofurans, Indoles, and Alkenes via Cyclopropene Ring Opening
作者:Rachel J. Ross、Rubaishan Jeyaseelan、Mark Lautens
DOI:10.1021/acs.orglett.0c01655
日期:2020.6.19
The generation of metal carbenoids viaringopening of cyclopropenes by transition metals offers a simple entry into highly reactive intermediates. Herein, we describe a diastereoselective intermolecular rhodium-catalyzed cyclopropanation of heterocycles and alkenes using cyclopropenes as carbene precursors with a low loading of a commercially available rhodium catalyst. The reported method is scalable
Copper(I)-Catalyzed Carbometalation of Nonfunctionalized Cyclopropenes Using Organozinc and Grignard Reagents
作者:Kohei Endo、Takeo Nakano、Yutaka Ukaji
DOI:10.1055/s-0034-1379959
日期:——
A highly efficient method was developed for the copper(I)-catalyzed carbometalation of various nonfunctionalized and functionalized cyclopropenes. Electrophilic trapping of the cyclopropylmetal intermediates gave multifunctionalized cyclopropanes.