New Application of <i>N</i>-Halosuccinimide/PPh<sub>3</sub> for the Halogenation of Propargyl Alcohols to Haloallenes
作者:Xin Du、Yao Dai、Ren He、Shirong Lu、Ming Bao
DOI:10.1080/00397910902883587
日期:2009.10.12
Abstract An efficient and convenient new method has been developed for the preparation of haloallenes from propargyl alcohols by a reagent combination of N-halosuccinimide and triphenylphosphine. Chloroallenes 2 and bromoallenes 3 were obtained exclusively in moderate to good yields with regioselectivity.
Chemoselective Suzuki-Miyaura Coupling of Bromophenyl-Substituted Bromoallenes with Arylboronic Acids
作者:Liang Xu、Wenfeng Jiang、Xin Du、Xuesong Liu、Ming Bao、Ren He
DOI:10.1055/s-0031-1290682
日期:2012.6
Developing highly chemoselective Suzuki-Miyaura coupling reactions is of great value in the synthetic chemistry. Here we report the results of palladium-catalyzed reaction of bromoallenes containing an aryl bromide moiety with arylboronic acids. It is found that the C-Br insertion exclusively takes place on bromoallene rather than on the benzene ring. Theoretical calculations demonstrate that the corresponding oxidative addition intermediate has a much lower free energy.