Cyanoborohydrides are efficient reagents in the reductive addition reactions of alkyl iodides and electron-deficient olefins. In contrast to using tinreagents, the reaction took place chemoselectively at the carbon–iodine bond but not at the carbon–bromine or carbon–chlorine bond. The reaction system was successfully applied to three-component reactions, including radical carbonylation. The rate constant
氰基硼氢化物是烷基碘化物和缺电子烯烃的还原加成反应中的有效试剂。与使用锡试剂相反,该反应在碳碘键上发生化学选择,而在碳溴或碳氯键上没有发生。该反应体系已成功应用于三组分反应,包括自由基羰基化。通过动力学竞争法,在25°C下从氰基硼氢化四丁基铵中伯烷基脱氢的速率常数估计为<1×10 4 M –1 s –1。该值比氢化三丁基锡的值小3个数量级。
A New Coupling Reaction of Alkyl Iodides with Electron Deficient Alkenes Using Nickel Boride (cat.)−Borohydride Exchange Resin in Methanol
作者:Tae Bo Sim、Jaesung Choi、Meyoung Ju Joung、Nung Min Yoon
DOI:10.1021/jo961751f
日期:1997.4.1
addition reaction of alkyliodides with alpha,beta-unsaturated esters, nitriles, and ketones proceeds in moderate to excellent yields (50-95%) using Ni(OAc)(2) (0.05-0.2 equiv)-BER (3-5 equiv) in methanol in 1-9 h at room temperature or at 65 degrees C. Nickel boride on borohydride exchange resin (BER) is a good alternative reagent to tributyltin hydride for the coupling of alkyliodides with the electron
A new coupling reaction of alkyl iodides with α,β-unsaturated esters using Ni2B(cat.)-BER in methanol
作者:Tae Bo Sim、Jaesung Choi、Nung Min Yoon
DOI:10.1016/0040-4039(96)00510-2
日期:1996.4
Alkyliodides can be coupled with α,β-unsaturatedestersusingNi2B(0.05–0.2 eq)-BER(3 eq) in methanol at room temperature. Products (68–95%) are conveniently isolated, simply filtering the resin and evaporating the excess enoates and methanol.