Stereoselective Synthesis Of Functionalized 1, 3-Dienes Containing Silicon

This dissertation consists of two parts:Part one: (E)-α-Silylvinylzirconium complexes react with NBS or iodine to give (E)-α-halovinylsilanes, which can undergo palladium-catalyzed cross-coupling reactions with (E)-alkenylzirconium, providing a new and convenient approach to the stereoselective synthesis of (Z,E)-2-silyl-substituted 1,3-dienes.Part two: (E)-α-halovinylsilanes undergo a direct coupling reaction with (trimethylsilyl)acetylene in the presence of [Pd(PPh₃)₄] and Cul catalysts in pyrrolidine to give (Z)-2,4-bis(trimethylsilyl)-1-buten-3-ynes, which can undergo a desilylation reaction in the presence of potassium fluoride to provide a practical route to the stereoselective synthesis of (Z)-2-trimethylsilyl-1-buten-3-ynes. The Hydro-zirconation of (Z)-2-trimethylsilyl-1-buten-3-ynes with Cp₂Zr(H)Cl, followed by reacting with NBS or iodine, gave stereoselectively difunctionalized (E,Z)-1-halo-3-trimethylsilyl-1,3-dienes containing silicon and halogen. The Hydro-zirconation of (Z)-2-trimethylsilyl-l-buten-3-ynes with Cp₂Zr(H)Cl, followed by reacting with arylselenenyl bromrdes in THF, gave stereoselectively difunctionalized (E,Z)-1-arylselanyl-3-trimethylsilyl-1,3-dienes containing silion and selenium.