General Method for Preparation of Allenic Zinc Reagents by Three-Carbon Homologation of Triorganozincates: Convergent Three-Component Coupling of Propargylic Substrates, Triorganozincates, and Electrophilic Reagents
作者:Toshiro Harada、Takeshi Katsuhira、Atsushi Osada、Katsuhiro Iwazaki、Keiji Maejima、Akira Oku
DOI:10.1021/ja962136w
日期:1996.1.1
Allenic zinc reagents (R1R2CCC(R3)ZnL) are efficiently prepared by the reaction of propargylic substrates (R1R2C(X)C⋮CH, X = MeSO2O, Cl, R2NCO2) with a variety of triorganozincates ((R3)3ZnM; R3 = alkyl, alkenyl, aryl, M = Li, MgCl). Treatment of the allenic zinc reagents with D2O gives the corresponding deuteroallenes with high deuterium incorporation. The allenic zinc reagents thus prepared undergo
通过炔丙基底物 (R1R2C(X)C⋮CH, X = MeSO2O, Cl, R2NCO2) 与多种三有机锌酸盐 ((R3)3ZnM; R3 = 烷基,烯基,芳基,M = Li,MgCl)。用 D2O 处理丙二烯锌试剂会得到相应的具有高氘掺入量的氘丙二烯。如此制备的丙二烯锌试剂与多种亲电试剂(醛、酰氯、I2、NCS 和氯硅烷)在 γ 位发生区域选择性偶联反应,得到相应的炔丙基衍生物(R1R2C(El)C⋮CR3,El = RCH(OH), RCO, I, Cl, R3Si) 以高收率。含硅的丙二烯锌试剂 R1CHCC(CH2SiMe3)ZnL 和 R1CHCC(SiPhMe2)ZnL 很容易通过炔丙氨基甲酸酯 (R1CH(OCONPh2)C⋮CH) 与 (TMSCH2)3ZnLi 的反应以及溴炔丙甲磺酸酯 R1CH(OSO2Me) 的反应制备分别为 C⋮CBr 和 (PhMe2Si)3ZnLi。用亲电试剂连续处理这些试剂可提供