Esters as Radical Acceptors: β‐NHC‐Borylalkenyl Radicals Induce Lactonization by C−C Bond Formation/Cleavage on Esters
作者:Masaki Shimoi、Katsuhiro Maeda、Steven J. Geib、Dennis P. Curran、Tsuyoshi Taniguchi
DOI:10.1002/anie.201902001
日期:2019.5.6
Substituted propargyl acetates are converted into 4‐boryl‐2(5H)‐furanones upon thermolysis in the presence of an N‐heterocyclic carbene borane (NHC‐borane) and di‐tert‐butyl peroxide. The acetyl methyl group is lost during the reaction as methane. Evidence suggests that the reaction proceeds by a sequence of radical events including: 1) addition of an NHC‐boryl radical to the triple bond; 2) cyclization
Enantioselective Synthesis of Dihydropyrazoles by Palladium/Xu‐Phos‐Catalyzed Alleneamination of β, γ‐Unsaturated Hydrazones with Propargylic Acetates
作者:Shuting Zhang、Shuaijie Wu、Qiang Wang、Shiji Xu、Ying Han、Chao-Guo Yan、Junliang Zhang、Lei Wang
DOI:10.1002/anie.202300309
日期:——
A new robust palladium-catalyzed enantioselective alleneamination reaction of β,γ-unsaturated hydrazones with propargylic acetates is described. The salient features of this reaction include general substrate scope, well functional group tolerance, good yields and high enantioselectivities.
Cobalt-Promoted Electroreductive Cross-Coupling of Prop-2-yn-1-yl Acetates with Chloro(vinyl)silanes
作者:Chong-Hui Xu、Zhi-Qiang Xiong、Jing-Hao Qin、Xin-Hua Xu、Jin-Heng Li
DOI:10.1021/acs.orglett.3c02989
日期:2023.10.6
An electroreductive cross-coupling of prop-2-yn-1-yl acetates with chloro(vinyl)silanes for producing tetrasubstituted silylallenes is developed. The method enables the formation of a new C─Si bond through the cathodic reduction formation of the silyl radical, radical addition across the C≡C bond, the alkenyl anion intermediate formation, and deacetoxylation and represents a mild, practical route to
Nickel-Catalyzed Reductive Cross-Coupling of Propargylic Acetates with Chloro(vinyl)silanes: Access to Silylallenes
作者:Chong-Hui Xu、Zhi-Qiang Xiong、Jing-Hao Qin、Xin-Hua Xu、Jin-Heng Li
DOI:10.1021/acs.joc.3c02228
日期:2024.3.1
achieve. Herein, nickel-catalyzed reductive cross-coupling reactions between propargyl acetates and substituted vinyl chlorosilanes for the synthesis of tetrasubstituted silylallenes are described. Therein, metallic zinc is a crucial reductant that effectively enables two electrophilic reagents to selectively construct C(sp2)–Si bonds. Additionally, a Ni-catalyzed reductive mechanism involving a radical