the corresponding trisubstitutedalkenes in which the tosyl group has been selectively substituted by an aryl or an alkyl group with retention of configuration. Finally, the cross coupling reaction of these vinyl selenides with methylmagnesium bromide, in the presence of a nickel catalyst, occurs with retention of configuration and affords the selenium free trisubstitutedalkenes.
Stereospecific Formation of Chalcogenoenynes via Palladium Catalysed Cross-Coupling Reaction of α-Bromovinylic Chalcogenides
作者:Antonio L. Braga、Gilson Zeni、Leandro H. de Andrade、Claudio C. Silveira、Hélio A. Stefani
DOI:10.1055/s-1998-2006
日期:1998.1
α-Bromovinylic chalcogenides undergo direct coupling reaction with terminal alkynes in the presence of palladium(0) in pyrrolidine at room temperature to give chalogenoenynes in good yields.
Stereoselective synthesis of (Z,E)-2-phenylselenobutadienes by palladium-catalyzed cross-coupling reaction
作者:Ming-Zhong Cai、Jia-Di Huang、Chun-Yun Peng
DOI:10.1016/s0022-328x(03)00583-7
日期:2003.9
Hydrozirconation of 1-alkynes gives (E)-alkenylzirconium complexes 3, which are cross-coupled with (E)-α-phenylselenovinyl bromides (4) in the presence of tetrakis (triphenylphosphine) palladium catalyst to afford (Z,E)-2-phenylselenobutadienes (5) in good yields.
Addition of hydrogen halides to acetylenic selenides. Synthesis of 1-halo-1-selenoalkenes
作者:João V. Comasseto、Paulo H. Menezes、Helio A. Stefani、Gilson Zeni、Antônio L. Braga
DOI:10.1016/0040-4020(96)00505-4
日期:1996.7
Acetylenic selenides react with HX (X=Cl, Br, I) at room temperature to give 1-halo-1-selenoalkenes in good yields. The 1-iodo-1-selenoalkenes were transformed into the corresponding vinylic organometallics (M=Zn, Cu, Cr).