Reaction of Trialkyl(dibromomethyl)silanes or 1,2-Bis(dibromomethyl)benzene with Triorganomanganates. A Facile and Selective Synthesis of Alkenylsilanes and 1,2-Diaryl-1,2-dihydrobenzocyclobutenes
stereoselectivity in good yields. The reaction of trialkyl(dibromomethyl)silanes with alkylmagnesium halides proceeded in the presence of a catalytic amount of manganese(II) chloride. Treatment of 1,2-bis(dibromomethyl)benzene with triphenylmanganate gave 1,2-diphenyl-1,2-dihydrobenzocyclobutene.
用衍生自氯化锰 (II) 和三摩尔量的格氏试剂或烷基锂的三烷基锰酸盐处理三烷基(二溴甲基)硅烷,以良好的收率提供具有高立体选择性的(E)-1-三烷基甲硅烷基-1-烯烃。三烷基(二溴甲基)硅烷与烷基卤化镁的反应在催化量的氯化锰(II)存在下进行。用三苯基锰酸盐处理 1,2-双(二溴甲基)苯得到 1,2-二苯基-1,2-二氢苯并环丁烯。
tert-Butyldimethylsilyldihalomethyllithium as a dihalomethylene dianion synthon. 1,3-Rearrangement and 1,4-rearrangement of silyl group from carbon to oxide
One-pot synthesis of R1CH(OSiMe2-t-Bu)CX2CH(OH)R2 (X=Cl, Br) successive addition of two different aldehydes (R1CHO and R2CHO) has been achieved starting from tert-butyldimethylsilyldihalomethyllithium. Treatment of a THF solution of the title carbanion (X=Cl) with p-MeOC6H4CHO or n-BuCHO followed by an addition of HMPA and benzaldehyde gave the corresponding 1,3-diol monosilyl ether in 83% or 45% yield
Preparation of alkenesvia a manganate-induced alkylation–elimination sequence was investigated. The reaction of 2-alkoxy-1,1-dibromoalkanes with trialkylmanganates afforded disubstituted or trisubstitutedalkenes. Treatment of 2-alkoxy-1,1,1-tribromoalkanes with trialkylmanganates provided trisubstituted or tetrasubstituted alkenes through bromine–metal exchange, transfer of two alkyl groups from
Treatment of dibromomethyltrialkylsilanes with butylmagnesium bromide in the presence of a catalytic amount of manganese(II) chloride provided (E)-1-trialkylsilyl-1-pentenes with high stereoselectivity in good yields.
light-induced palladium-catalyzed homologative three-component synthesis of allylic amines has been developed. This protocol proceeds via a unique mechanism involving two distinct cycles enabled by the same Pd(0) catalyst: a visible light-induced hybrid radical alkyl Heck reaction between 1,1-dielectrophile and styrene, followed by the “in dark” classical Tsuji–Trost-type allylic substitution reaction. This