Manganese‐Catalyzed C−H Functionalizations: Hydroarylations and Alkenylations Involving an Unexpected Heteroaryl Shift
作者:Chengming Wang、Ai Wang、Magnus Rueping
DOI:10.1002/anie.201704682
日期:2017.8.7
A manganese-catalyzed regio- and stereoselective hydroarylation of allenes is reported. The C−H functionalization method provides access to various alkenylated indoles in excellent yields. Moreover, a hydroarylation/cyclization cascade involving an unexpected C−N bond cleavage and aryl shift has been developed, which provides a new synthetic approach to substituted pyrroloindolones.
contiguous three stereocenters has been a long-standing challenging task in organic synthesis. Herein we present a phoshine-catalyzed highly regio-, diastereo- and enantioselective [3+2] cycloaddition of γ-substitutedallenoates with β-perfluoroalkyl enones, delivering a wide range of densely functionalized perfluoroalkylated cyclopentenes with three contiguous chiral stereocenters.
Visible light photoredox catalysis: regioselective radical addition of aminoalkyl radicals to 2,3-allenoates
作者:Xiaojun Dai、Renjie Mao、Baochuan Guan、Xiaoliang Xu、Xiaonian Li
DOI:10.1039/c5ra10491b
日期:——
The regioselectiveaddition of α-aminoalkyl radicals to 2,3-allenoates by visible-light-mediated electron transfer using 1 mol% of Ru(bpy)3(BF4)2 as a photocatalyst was successfully established. This photoredox protocol is a simple and effective method for the synthesis of unsaturated γ-aminobutyric ester derivatives.
PPh3-catalyzed β-selective addition of α-fluoro β-dicarbonyl compounds to allenoates
作者:Yong-Liang Liu、Xiao-Ping Wang、Jie Wei、Ya Li
DOI:10.1016/j.tet.2021.132577
日期:2022.1
A highly selective phosphine-catalyzed β-addition of α-fluoro β-dicarbonylcompounds to allenoates has been developed. Both α-fluoro β-diketones and α-fluoro β-keto esters prove to be competent fluorocarbon nucleophiles, giving a series of the β-addition products bearing a fluorinated quaternary carbon center in good to excellent yields and with excellent regioselectivities. A plausible reaction pathway
β-substituted unsaturated sulfone. By means of visible-light photoredox catalysis, the free radicals produced by p-toluenesulfonic acid reacted with multisubstituted allenes to obtain Markovnikov-type vinyl sulfones with Ru(bpy)3Cl2 or Rhodamine B as photocatalyst. The yield of this reaction could reach up to 91%. A series of unsaturated sulfones would be used for further transformation to some valuable compounds