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。
Ligand-Promoted Alkylation of C(sp<sup>3</sup>)–H and C(sp<sup>2</sup>)–H Bonds
作者:Ru-Yi Zhu、Jian He、Xiao-Chen Wang、Jin-Quan Yu
DOI:10.1021/ja508165a
日期:2014.9.24
9-Methylacridine was identified as a generally effective ligand to promote a Pd(II)-catalyzed C(sp3)–H and C(sp2)–H alkylation of simple amides with various alkyl iodides. This alkylation reaction was applied to the preparation of unnatural amino acids and geometrically controlled tri- and tetrasubstituted acrylic acids.
Tin-free Giese reaction and the related radical carbonylation process proceeded efficiently in the presence of sodium cyanoborohydride and tetrabutylammonium cyanoborohydride. The reaction took place chemoselectively at the carbon-iodine bond but not at the carbon-bromine and carbon-chlorine bonds. The iodine atom transfer followed by hydride reduction of the resulting carbon-iodine bond is proposed
Stereospecific Synthesis of <i>E</i>-Alkenes through Anti-Markovnikov Hydroalkylation of Terminal Alkynes
作者:Avijit Hazra、Jason Chen、Gojko Lalic
DOI:10.1021/jacs.9b04800
日期:2019.8.14
We have developed a method for stereospecificsynthesis of E-alkenes from terminal alkynes and alkyl iodides. The hydroalkylation reaction is enabled by a cooperative action of copper and nickel catalysts and proceeds with excellent anti-Markovnikov selectivity. We demonstrate the broad scope of the reaction, which can be accomplished in the presence of esters, nitriles, aryl bromides, ethers, alkyl