Chemoselective Hydrosilylation of the α,β-Site Double Bond in α,β- and α,β,γ,δ-Unsaturated Ketones Catalyzed by Macrosteric Borane Promoted by Hexafluoro-2-propanol
作者:Xiao-Yu Zhan、Hua Zhang、Yu Dong、Jian Yang、Shuai He、Zhi-Chuan Shi、Lei Tang、Ji-Yu Wang
DOI:10.1021/acs.joc.0c00568
日期:2020.5.15
The B(C6F5)3-catalyzed chemoselective hydrosilylation of α,β- and α,β,γ,δ-unsaturated ketones into the corresponding non-symmetric ketones in mild reaction conditions is developed. Nearly 55 substrates including those bearing reducible functional groups such as alkynyl, alkenyl, cyano, and aromatic heterocycles are chemoselectively hydrosilylated in good to excellent yields. Isotope-labeling studies
IODINE CATALYZED CASCADE SYNTHESIS OF FLAVONE DERIVATIVES FROM 2'-ALLYLOXY-α, β-DIBROMOCHALCONES
作者:BEENA R NAWGHARE、SUNIL V GAIKWAD、ABDUL RAHEEM、PRADEEP D LOKHANDE
DOI:10.4067/s0717-97072014000100009
日期:——
Synthesis of flavones from 2'-allyloxy-α, β-dibromochalcones has been described. The iodine induced oxidative cyclization of 2'-allyloxy-α, β-dibromochalcones results into the formation of 3-bromoflavanones which ultimately gives flavones. Dehydrobromination of 3-bromoflavanone to give flavone is the preferred reaction over dehydrogenation. 6 3-Bromoflavones are used in drugs and for synthesis of alkylated