Department of Chemistry, New York University , 100 Washington Square East New York, New York 10003, United States.
J Org Chem. 2017 Jul 7;82(13):6895-6903. doi: 10.1021/acs.joc.7b01034. Epub 2017 Jun 21.
Carboxylate groups are ubiquitous in bioactive molecules. The syntheses of carboxylates from petroleum feedstock require a series of oxidation reactions. CO represents a cheap and sustainable, preoxidized C1 source. Herein, we describe a simple, selective, and mild procedure for the construction of (hetero)cyclic α,β-unsaturated carboxylic acids from 1,6- and 1,7-enyes and CO. Terminal 1,7-enynes and sterically hindered alkenes experience a change in regioselectivity and form unconjugated carboxylic acids. Mechanistic studies of the reductive cyclization suggest a hydride insertion pathway, explaining the change in regioselectivity caused by steric effects and distinguishing this work from previous reactions involving CO.
羧基在生物活性分子中普遍存在。从石油原料合成羧酸需要一系列氧化反应。CO 代表了一种廉价且可持续的预氧化 C1 源。在此，我们描述了一种从 1,6-和 1,7-烯和 CO 构建（杂）环α，β-不饱和羧酸的简单、选择性和温和的方法。末端 1,7-烯炔和位阻烯烃经历了区域选择性的变化，形成了非共轭羧酸。还原环化的机理研究表明了氢化物插入途径，解释了空间位阻引起的区域选择性变化，并将这项工作与以前涉及 CO 的反应区分开来。
