Highly Stereoselective Semihydrogenation of Alkynes Promoted by Nickel(0) Nanoparticles
作者:Francisco Alonso、Iñaki Osante、Miguel Yus
DOI:10.1002/adsc.200505327
日期:2006.2
A new method for the highlystereoselective cis-semihydrogenation of internal alkynes is described based on in situ generated Ni(0) nanoparticles and molecular hydrogen. This reduction system also allows the semihydrogenation of terminal alkynes.
Ethyl Cyanoformate/Hydrogen Peroxide and Related Combination Systems, Novel Epoxidizing Systems of Olefins
作者:Yukio Masaki、Tsuyoshi Miura、Isao Mukai、Akichika Itoh、Hirohisa Oda
DOI:10.1246/cl.1991.1937
日期:1991.11
A combination system of ethyl cyanoformate and hydrogen peroxide was found to epoxidize olefins in a stereospecific manner at room temperature. Asymmetric epoxidation was observed with menthyl cyanoformate/hydrogen peroxide system.
A reagent combination system, tetracyanoethylene-30% hydrogen peroxide, was found to epoxidize olefins efficiently in acetonitrile at room temperature in a stereospecific manner with retention of the configuration of the double bond.
Regiochemical control of the ring opening of 1:2-epoxides by means of chelating processes. 10. Synthesis and ring opening reactions of mono- and difunctionalized cis and trans aliphatic oxirane systems
The regiochemical outcome of the ring opening of 1:2-epoxides through chelation processes assisted by metal ions, was verified in mono- and difunctionalized aliphatic oxirane systems bearing the heterofunctionality (OR) in an homoallylic and/or allylic relationship to the oxirane ring. The effect of the distance of the OR functionality from the oxirane ring and of the type of protective group on the
Copper catalyzed hydrodefluorination of propargylic gem-difluorides with “triple bonds migration”
作者:Ting Wang、Zhirong Li、Jiayi Hu、Tao Wu
DOI:10.1016/j.tet.2022.132897
日期:2022.8
A copper catalyzed hydrodefluorination of propargylic gem-difluorides was reported, in which two C–F bonds was reductive converted to C–H bonds and a new alkyne product was afforded with the triple bond migrating one methylene. Mechanistic studies show that the products are achieved by stepwise C–F bond reductive hydrogenation, and an allenyl monofluoride is proposed to be one of the active intermediates