chosen as standard C4 units of 1,3-diene precursors. The reactions are believed to undergo a unique cutting and insertion process, involving a CC bond cleavage of the enaminone and insertion of a new C(sp2) source with the formation of two C–C single bonds. A broad range of substrates can be used to synthesize the corresponding 1,3-dienes under very mild reaction conditions, including low catalyst-loading
Copper-Catalyzed Diastereo- and Enantioselective Desymmetrization of Cyclopropenes: Synthesis of Cyclopropylboronates
作者:Alejandro Parra、Laura Amenós、Manuel Guisán-Ceinos、Aurora López、José Luis García Ruano、Mariola Tortosa
DOI:10.1021/ja510419z
日期:2014.11.12
A novel Cu-catalyzed diastereo- and enantioselective desymmetrization of cyclopropenes to afford nonracemic cyclopropylboronates is described. Trapping the cyclopropylcopper intermediate with electrophilic amines allows for the synthesis of cyclopropylaminoboronic esters and demonstrates the potential of the approach for the synthesis of functionalized cyclopropanes.
描述了一种新型的 Cu 催化的环丙烯的非对映选择性和对映选择性去对称化,以提供非外消旋的环丙基硼酸酯。用亲电胺捕获环丙基铜中间体可以合成环丙基氨基硼酸酯,并展示了该方法合成功能化环丙烷的潜力。
Cobalt‐Catalyzed Diastereo‐ and Enantioselective Hydroalkylation of Cyclopropenes with Cobalt Homoenolates
作者:Wei Huang、Fanke Meng
DOI:10.1002/anie.202012122
日期:2021.2
in situ from ring‐opening of easily accessible cyclopropanols promoted by a chiral phosphine–cobalt complex is presented. Such a process represents the unprecedented and direct introduction of a wide range of functionalized alkylgroups without the need of pre‐formation of stoichiometric amounts of organometallic reagents onto the cyclopropane motif, affording multi‐substituted cyclopropanes in up to 99 %
Catalytic diastereo‐ and enantioselective hydroalkenylation of 3,3‐disubstituted cyclopropenes with readily accessible alkenylboronic acids, promoted by a chiral phosphine/Co complex, is presented. Such a process constitutes the unprecedented and direct introduction of a wide range of alkenyl groups onto the cyclopropane motif to afford multisubstituted cyclopropanes in up to 95 % yield with greater
Copper-Catalyzed Hydroamination: Enantioselective Addition of Pyrazoles to Cyclopropenes
作者:Minghao Wang、Julie C. Simon、Mengfei Xu、Stephanie A. Corio、Jennifer S. Hirschi、Vy M. Dong
DOI:10.1021/jacs.3c02971
日期:2023.7.12
Chiral N-cyclopropyl pyrazoles and structurally related heterocycles are prepared using an earth-abundant copper catalyst under mild reaction conditions with high regio-, diastereo-, and enantiocontrol. The observed N2:N1 regioselectivity favors the more hindered nitrogen of the pyrazole. Experimental and DFT studies support a unique mechanism that features a five-centered aminocupration.