alkylthiolation of alkenes, initiated by dimethyl(methylthio)sulfonium salts and the subsequent addition of various heteronucleophilies has been well-established. Regarding the use of carbon nucleophiles, however, only carefully designed sp-type carbon sources have been successfully applied. We herein present our findings on the methylthiolation of alkenes with dimethyl(methylthio)sulfonium trifluoromethanesulfonate
Rhodium-Catalyzed Arylzincation of Alkynes: Ligand Control of 1,4-Migration Selectivity
作者:Jialin Ming、Tamio Hayashi
DOI:10.1021/acs.orglett.8b02668
日期:2018.10.5
The addition of arylzinc reagents ArZnCl 1 to alkynes 2 was found to be catalyzed by rhodium complexes in the presence of a catalytic amount of zinc chloride. The selectivity in giving 2-arylalkenylzinc species 3 or ortho-alkenylarylzinc species 4, the latter of which is generated through 1,4-Rh migration from alkenyl to aryl in the catalytic cycle, is controlled by the ligands on rhodium. Ligands
Enantiomerically Enriched α-Borylzinc Reagents by Nickel-Catalyzed Carbozincation of Vinylboronic Esters
作者:Chenlong Zhang、Weipeng Hu、Gabriel J. Lovinger、Jing Jin、Jingjia Chen、James P. Morken
DOI:10.1021/jacs.1c05274
日期:2021.9.8
In this paper is described a synthesis of enantiomerically enriched, configurationally stable organozinc reagents by catalyticenantioselective carbozincation of a vinylboronic ester. This process furnishes enantiomerically enriched α-borylzinc intermediates that are shown to undergo stereospecific reactions, producing enantioenriched secondary boronic ester products. The properties of the intermediate
Rhodium-Catalyzed Desymmetric Arylation of <i>γ,γ</i>-Disubsituted Cyclohexadienones: Asymmetric Synthesis of Chiral All-Carbon Quaternary Centers
作者:Yu Qiao、Shiming Bai、Xiao-Feng Wu、Ying Yang、He Meng、Jialin Ming
DOI:10.1021/acs.orglett.2c00225
日期:2022.2.25
desymmetric arylation of prochiral cyclohexadienones with ArZnCl in the presence of an (R)-segphos–rhodium catalyst gave high yields of the corresponding cyclohexenones, which contain a chiral arylated carbon center at the β-position and a chiral all-carbon quaternary center at the γ-position, with high diastereo- and enantioselectivities. This catalytic system was also applied to the arylation of spirocarbocyclic
在 ( R )-segphos-铑催化剂存在下,前手性环己二烯酮与 ArZnCl 的不对称芳基化得到高产率的相应环己烯酮,其在β位含有手性芳基化碳中心,在γ-位,具有高非对映选择性和对映选择性。该催化体系还应用于螺碳环环己二烯酮的芳基化,并提供了相应的带有高 dr 和 ee 的手性螺季碳的环己烯酮。
Rhodium-Catalyzed Three-Component Reaction of Alkynes, Arylzinc Chlorides, and Iodomethanes Producing Trisubstituted/Tetrasubstituted Alkenes with/without 1,4-Migration
作者:He Meng、Shiming Bai、Yu Qiao、Ting He、Weiyi Li、Jialin Ming
DOI:10.1021/acs.orglett.2c02299
日期:2022.7.29
A three-component reaction of alkynes, arylzinc chlorides, and iodomethanes was found to proceed in the presence of a rhodium catalyst to give high yields of trisubstituted/tetrasubstituted alkenes. The usual arylzinc chlorides only gave trisubstitutedalkenes, generated through a migratory carbozincation–cross-coupling sequence, where 1,4-Rh migration from an alkenyl carbon to an aryl carbon occurred