Nickel-Catalyzed Decarboxylative Coupling of Redox-Active Esters with Aliphatic Aldehydes
Nickel-Catalyzed Decarboxylative Coupling of Redox-Active Esters with Aliphatic Aldehydes
复制标题
镍催化氧化还原活性酯与脂肪醛的脱羧偶联
DOI：
10.1021/jacs.1c11170
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发表时间：
2021
影响因子：
15
通讯作者：
Montgomery, John
中科院分区：
文献类型：
--
作者：
Xiao, Jichao;Li, Zhenning;Montgomery, John
将烷基片段加到脂肪醛中是一种非常理想的片段偶联转化方法，但现有方法面临着与常用亲核试剂的碱性和不稳定性有关的操作挑战。在这里，我们报道了使用易于获得的双恶唑啉(BIOX)配体的镍催化可以催化氧化还原活性的酯与脂肪醛的还原偶联，使用金属锌作为还原剂来提供硅基保护的仲醇。该方案操作简单，在温和的条件下进行，并能容忍各种官能团。最初的机制研究表明，这是一条自由基链途径。此外，烷基对甲苯磺酸盐和环氧化物是这种转化的合适的烷基前体，为脂肪醛的官能化提供了一套广泛的催化反应。
The addition of alkyl fragments to aliphatic aldehydes is a highly desirable transformation for fragment couplings, yet existing methods come with operational challenges related to the basicity and instability of the nucleophilic reagents commonly employed. We report herein that nickel catalysis using a readily available bioxazoline (BiOx) ligand can catalyze the reductive coupling of redox-active esters with aliphatic aldehydes using zinc metal as the reducing agent to deliver silyl-protected secondary alcohols. This protocol is operationally simple, proceeds under mild conditions, and tolerates a variety of functional groups. Initial mechanistic studies suggest a radical chain pathway. Additionally, alkyl tosylates and epoxides are suitable alkyl precursors to this transformation providing a versatile suite of catalytic reactions for the functionalization of aliphatic aldehydes.