Catalytic enantioselective allene–anhydride approach to β,γ-unsaturated enones bearing an α-all-carbon-quarternary center
作者:Yuan Yuan、Xue Zhang、Hui Qian、Shengming Ma
DOI:10.1039/d0sc03227a
日期:——
A protocol of highly regio- and enantioselective copper-catalyzed hydroacylation of the non-terminal CC bond in 1,1-disubstituted terminal allenes with anhydrides has been developed. Both aromatic and aliphatic carboxylic anhydrides are applicable to the efficient construction of all carbon quarternary centers connected with a versatile CC bond and a useful ketone functionality. The synthetic potentials
Fluorinative Rearrangements of Substituted Phenylallenes Mediated by (Difluoroiodo)toluene: Synthesis of α-(Difluoromethyl)styrenes
作者:Zhensheng Zhao、Léanne Racicot、Graham K. Murphy
DOI:10.1002/anie.201706798
日期:2017.9.11
(difluoroiodo)toluene in the presence of 20 mol % BF3⋅OEt2 to yield α‐difluoromethyl styrenes. This unprecedented reaction was entirely chemoselective for the internal allene π bond, and showed remarkable regioselectivity during the fluorination event. Substituted phenylallenes, phenylallenes possessing both phenyl‐ and α‐allenyl substituents, and diphenylallenes were investigated, and good functional‐group
Chlorination of phenylallene derivatives with 1-chloro-1,2-benziodoxol-3-one: synthesis of <i>vicinal</i>-dichlorides and chlorodienes
作者:Zhensheng Zhao、Graham K Murphy
DOI:10.3762/bjoc.14.67
日期:——
Allyl and vinyl chlorides represent important structural motifs in organic chemistry. Herein is described the chemoselective and regioselective reaction of aryl- and α-substituted phenylallenes with the hypervalent iodine (HVI) reagent 1-chloro-1,2-benziodoxol-3-one. The reaction typically results in vicinal dichlorides, except with proton-containing α-alkyl substituents, which instead give chlorinated
A convenient access to allylic triflones with allenes and triflyl chloride in the presence of (EtO)<sub>2</sub>P(O)H
作者:Jixiang Ni、Yong Jiang、Zhenyu An、Jingfeng Lan、Rulong Yan
DOI:10.1039/c9cc03096d
日期:——
A simple method for the preparation of allylic triflones from allenes and triflyl chloride in the presence of (EtO)2P(O)H has been developed. The features of this reaction are catalyst-free and simple starting substrates. This method tolerates diverse functional groups and substituted allylic triflones are obtained in moderate to good yields.
Regioselective Diboron-Mediated Semireduction of Terminal Allenes
作者:Ashley M. Gates、Webster L. Santos
DOI:10.1055/s-0039-1690207
日期:2019.12
A method for the regioselective reduction of the terminaldoublebond of 1,1-disubstituted allenes has been developed. In the presence of a palladium catalyst, tetrahydroxydiboron and stoichiometric water, allene semireduction proceeds in high yield to afford Z-alkenes selectively.