The Synthesis Of Se-Br, Si-Zr, Sn-Zr 1, 1-Difunctional Group Reagents And Their Applicat-ions In High Selective Synthesis

This dissertation consists of three parts:Part one: We developed a novel approach to the stereoselective synthesis of (Z,E)-2-phenylselenobutadienes by the cross-coupling reaction of (E)-a-bromovinylselenides and alkenylzirconium complexes in the presence of palladium(0) catalyst. We found that (E)-a-bromovinylselenides underwent cross-coupling reactions with Grignard reagents catalyzed by tetrakis(triphenyl-phosphine)palladium(0) to give stereoselectively (Z)-1,2-disubstituted alkenyl-selenides, which can undergo NiCl2(PPh3)2-catalyzed cross-coupling reaction with Grignard reagents, providing a convenient approach to the stereoselective synthesis of trisubstituted alkenes.Part two: (E)-α-Silylvinylzirconium complexes were prepared by the hydr-ozirconation of alkynylsilanes with Cp2Zr(H)Cl. It was found that (E)-α-silylvinylzirconium complexes reacted with NBS or iodine to afford stereoselectively (E)-α-halovinylsilane, which were reacted with terminal acetylenes in the presence of Cul and Pd(PPh3)4, providing a convenient approach to the stereoselective synthesis of 1,3-enynylsilanes. (E)-α-Silylvinyl tellurides were synthesized stereoselectively via the hydrozirconation of alkynylsilanes, followed by the reaction with aryltellurenyl iodides. (E)-α-Silylvinyltellurides can undergo the cross coupling reaction with Grignard reagents in the presence of Ni(PPh3)2Cl2 catalyst to give (Z)-l,2-disubstituted vinylsilanes .Part three: (E)-α-Aryltellurenylvinylstannanes was synthesized stereo-s electively via the hydrozirconation of alkynylstannanes, followed by the reaction with aryltellurenyl iodides. (E)-α-Aryltellurenylvinylstannanes can react with aryl iodides in the presence of Cul and Pd(PPh3)4 to give (E)-1,2-di-s ubstituted vinyltellurides, which can undergo NiCl2(PPh3)2-catalyzed cross-coupling reaction with Grignard reagents, providing another convenient approach to the stereoselective synthesis of trisubstituted alkenes.