A Radical-Initiated Fragmentary Rearrangement Cascade of Ene-Ynamides to [1,2]-Annulated Indoles via Site-Selective Cyclization
作者:Sifan Li、Yu Wang、Zibo Wu、Weiliang Shi、Yibo Lei、Paul W. Davies、Wei Shu
DOI:10.1021/acs.orglett.1c02519
日期:2021.9.17
Herein, a radical triggered fragmentary cyclization cascade reaction of ene-ynamides is presented, providing a rapid access into [1,2]-annulated indoles by an intermolecular radical addition, intramolecular cyclization, desulfonylative aryl migration, and site-selective C(sp2)-N cyclization sequence. DFT calculations support oxidation of N-centered radical species to cations prior to the C–N bond formation
Nickel-Catalyzed Difunctionalization of Alkynyl Bromides with Thiosulfonates and N-Arylthio Succinimides: A Convenient Synthesis of 1,2-Thiosulfonylethenes and 1,1-Dithioethenes
cesium carbonate is described. An operationally simple and highly regioselective atom transfer radical addition (ATRA) of alkynyl bromides provides a wide range of (E)-1,2-thiosulfonylethenes (α-aryl-β-thioarylvinyl sulfones) in moderate to high yields. The extensive substrate scope of both alkynyl bromides and thiosulfonates is explored with a broad range of functional groups. Indole-derived 1,1-bromoalkenes
A New and Facile Method for Stereoselective Synthesis of (<i>E</i>)-Styryl Bromides by the Reduction of 1,1-Dibromoalkenes Using LiAlH<sub>4</sub>-EtOAc (1:1)
A facile method for stereoselectivesynthesis of (E)-styryl bromides by the reduction of 1,1-dibromoalkenes using LiAlH 4 -EtOAc (1:1) is described. We believe that the present procedure is a good alternative to the Tokuda's microwave method with good stereoselectivity.
Regioselective Fluorination of 1-(2,2-Dibromovinyl)benzene Derivatives with Wet Tetra-<i>n</i>-butylammonium Fluoride: One-Pot Synthesis of (<i>Z</i>)-1-(2-Bromo-1-fluorovinyl)benzenes
A direct fluorination of 1-(2,2-dibromovinyl)benzene derivatives using wet tetra-n-butylammonium fluoride (TBAF·3H2O) as either a base or a fluorine source in toluene was accomplished, which provided (Z)-1-(2-bromo-1-fluorovinyl)benzene compounds in up to 81% yields with high regioselectivities. This reaction results strongly depend upon the reaction conditions. The mechanism of this reaction was investigated