Development of New Methods for Carbonylation by Free-Radical Reactions

提出了一种新的基于自由基反应的羰基化方法。由烷基自由基加入一氧化碳中产生的酰基自由基，已被氢化锡有效捕获。通过这一序列，实现了有机卤化物自由基甲酰化成相应醛的过程。当烯烃也存在于反应体系中时，烷基自由基被一氧化碳捕获形成酰基自由基，随后该自由基与烯烃加成，从而有效地生成不对称酮。三甲基硅烷也可用作自由基介质。这个序列代表了一氧化碳双烷基化的一种独特方法。从4-戊基卤化物开始，羰基环化生成环戊酮也会受到影响。所有这些发现表明，自由基羰基化是将一氧化碳引入有机分子的有效方法。

A novel carbonylation method based on free-radical reactions has been developed. Acylradicals, generated by the addition of alkyl free-radicals to carbon monoxide, have been effectively trapped by tin hydride. Through this sequence, the free-radical formylation of organo halides to the corresponding aldehydes was realized. When an alkene was also present in the reaction system, the trapping of the alkyl free-radical by carbon monoxide to form an acyl free-radical and the subsequent addition of that radical to the alkene took place efficiently to give and unsymmetrical ketone. Tris(trimethylsily)silane can also be used for a free-radical mediator. This sequence represents a unique method for the double alkylation of carbon monoxide. Carbonylative cyclizations to give cyclopentanones can also be affected starting with 4-pentenyl halides. All of these findings that free-radical carbonylation is useful method for the introduction of carbon monoxide into organic molecules.