Merck Center for Catalysis at Princeton University, Princeton, New Jersey 08544, United States.
J Am Chem Soc. 2022 Apr 13;144(14):6185-6192. doi: 10.1021/jacs.2c02062. Epub 2022 Mar 30.
Alcohols and carboxylic acids are among the most commercially abundant, synthetically versatile, and operationally convenient functional groups in organic chemistry. Under visible light photoredox catalysis, these native synthetic handles readily undergo radical activation, and the resulting open-shell intermediates can subsequently participate in transition metal catalysis. In this report, we describe the C()-C() cross-coupling of alcohols and carboxylic acids through the dual combination of -heterocyclic carbene (NHC)-mediated deoxygenation and hypervalent iodine-mediated decarboxylation. This mild and practical Ni-catalyzed radical-coupling protocol was employed to prepare a wide array of alkyl-alkyl cross-coupled products, including highly congested quaternary carbon centers from the corresponding tertiary alcohols or tertiary carboxylic acids. We demonstrate the synthetic applications of this methodology to alcohol -alkylation and formal homologation, as well as to the late-stage functionalization of drugs, natural products, and biomolecules.
醇和羧酸是有机化学中最常见、用途最广泛、操作最方便的官能团之一。在可见光光氧化还原催化下,这些天然的合成手性很容易被自由基激活,生成的开壳中间体随后可以参与过渡金属催化。在本报告中,我们描述了通过氮杂环卡宾(NHC)介导的脱氧和高价碘介导的脱羧双重组合,实现醇和羧酸的 C()-C()交叉偶联。该温和实用的镍催化自由基偶联反应方案被用于制备广泛的烷基-烷基交叉偶联产物,包括由相应的叔醇或叔羧酸衍生的高度拥挤的季碳原子中心。我们展示了该方法在醇烷基化和形式同系化以及药物、天然产物和生物分子的后期功能化方面的合成应用。