Nickel(0)-catalyzed disilylative and silastannylative cyclizations of 1,3-diene and tethered aldehyde
作者:Nozomi Saito、Miwako Mori、Yoshihiro Sato
DOI:10.1016/j.jorganchem.2006.03.047
日期:2007.1
Nickel(0)-catalyzed bismetallative cyclization of 1,3-diene and a tethered aldehyde in the presence of PhF2SiSiMe3 or Me3SiSnBu3 gave the corresponding cyclized product having an allylsilyl or an allylstannyl unit in the side chain in good yields. The cyclized product obtained from the reaction in the presence of Me3SiSnBu3 had reactivity as an allylstannane derivative, and the coupling reaction with
A New Reactive System for Catalytic Bis-Silylation of Acetylenes and Olefins
作者:Fumiyuki Ozawa、Mitsuru Sugawara、Tamio Hayashi
DOI:10.1021/om00020a042
日期:1994.8
Reaction of diphenylacetylene (1a) with Me3SiSiF2Ph (1 equiv) in toluene in the presence of a palladium catalyst (1 mol %) generated in situ by mixing [Pd(eta3-allyl)CI]2 and PMe2Ph (2.2 equiv/Pd) was completed in 1.4 h at room temperature to give the bis-silylation product (Z)-1-(difluorophenylsilyl)-1,2-diphenyl-2-(trimethylsilyl)ethene (2a) in 95% yield. In similar catalytic systems, a variety of acetylenes and olefins, including 3-hexyne, 1-phenyl-1-propyne, phenylacetylene, 1-octyne, norbornene, styrene, and 1-octene, were bis-silylated in 64-96% yields. The highly reactive nature of the present catalytic system was studied in stoichiometric systems. The presumed intermediates trans-Pd(SiMe3)(SiF2Ph)L2 (L = PMe3 (4a), PMe2Ph (4b)) were prepared by oxidative addition of Me3SiSiF2Ph toward Pd(styrene)L2 complexes (L = PMe3 (3a), PMe2Ph (3b)). Complex 4b reacted with diphenylacetylene (3 equiv) in toluene-ds at -20-degrees-C to give the bis-silylation product (Z)-2a in 82% yield together with Pd(PhC=Ph)(PMe2Ph)2 (93%). Treatment of 4a with dimethyl acetylenedicarboxylate (1 equiv) in toluene at -20-degrees-C instantly formed a palladium(0) complex coordinated with bis-silylated olefin, Pd(X)-(MeO2C)(Me3Si)C=C(SiF2Ph)(CO2Me)}(PMe3)2 (6). The structure of 6 was determined by an X-ray diffraction study. Crystal data for 6 THF : C21H38O4P2F2-Si2Pd.C4H8O, a = 15.585(2) angstrom, b = 12.438(2) angstrom, c = 17.652(2), beta = 93.86(1)-degrees, V = 3413.9(8) angstrom3, monoclinic P2(1)/n, Z = 4.
UHLIG, WOLFRAM;TZSCHACH, ALFRED, Z. CHEM., 30,(1990) N, C. 254