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。
6,6-Dicyanopentafulvenes: Teaching an Old Dog New Tricks
作者:Aaron D. Finke、François Diederich
DOI:10.1002/tcr.201402060
日期:2015.2
DCFs was exploited computationally for the first time. Shortly after the report of the first rational synthesis of DCFs, we discovered that DCFs had a vast and astonishing array of reactivities to form new molecular entities. Simple, catalyst-free reactions between DCF acceptors and electron-rich donors led to the formation of scaffolds of exceptional complexity. Furthermore, our discovery that DCFs are
Formation of Five- and Seven-Membered Rings Enabled by the Triisopropylsilyl Auxiliary Group
作者:Dmitry L. Usanov、Hisashi Yamamoto
DOI:10.1021/ol203209b
日期:2012.1.6
to 2-indanones from aldehydes was established. The introduction of a triisopropylsilyl group greatly facilitated Meinwald rearrangement of the intermediate epoxides and alleviated the necessity of polysubstitution for the clean formation of indenes and cyclopentadienes via cyclodehydration of allylic alcohols; unprecedented freedom with respect to the product structure was thus achieved. The developed
The titanocene(III) chloridemediated opening of silyloxiranes has been examined. Electron transfer from the metal leads to α-silyl radicals with total regiocontrol. The radicals could be trapped by various olefins, and the corresponding adducts were obtained in good yields (Table). Further substitution of the oxirane by alkyl groups proved detrimental to the reactions, but ring opening remained essentially
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.