在此,从容易获得的邻甲酰基(或邻酰基)肉桂酸酯和吲哚描述了一种直接的布朗斯台德酸促进的多米诺骨牌途径来构建取代的苯并[ b ]咔唑。值得注意的是,该方案适合保护无基团的吲哚。值得注意的是,该方法基于在温和且无金属的反应条件下单锅区域选择性构建两个新的 C-C 键和芳构化序列。机理研究表明,通过在邻甲酰基(或邻酰基)肉桂酸酯的羰基碳上用两个吲哚分子进行双重芳族取代,最初形成双吲哚取代中间体,然后进行分子内环化和芳构化,排除第二个吲哚分子。此外,还通过放大和衍生反应(包括光物理性质研究)说明了该方法的有效性。
在此,从容易获得的邻甲酰基(或邻酰基)肉桂酸酯和吲哚描述了一种直接的布朗斯台德酸促进的多米诺骨牌途径来构建取代的苯并[ b ]咔唑。值得注意的是,该方案适合保护无基团的吲哚。值得注意的是,该方法基于在温和且无金属的反应条件下单锅区域选择性构建两个新的 C-C 键和芳构化序列。机理研究表明,通过在邻甲酰基(或邻酰基)肉桂酸酯的羰基碳上用两个吲哚分子进行双重芳族取代,最初形成双吲哚取代中间体,然后进行分子内环化和芳构化,排除第二个吲哚分子。此外,还通过放大和衍生反应(包括光物理性质研究)说明了该方法的有效性。
An unusual doubly substituted product from the phase-transfer-catalyzed Heck reactions of o-bromobenzaldehydes with methyl acrylate
作者:Sanath K. Meegalla、Nicholas J. Taylor、Russell Rodrigo
DOI:10.1021/jo00034a041
日期:1992.4
The reactions of o-bromobenzaldehydes with methyl acrylate under Heck conditions and with phase-transfer catalysis to yield significant amounts of doubly substituted deformylated products 1A-E in addition to the expected o-formyl cinnamates 2A-E are reported. X-ray crystallography of one such product (4) established that the bromine was replaced by a propionate and the formyl group by an acrylate residue. Employment of deuterium-labeled substrates showed that the hydrogen atom of the formyl group of the substrate was transferred intramolecularly and regiospecifically to the benzylic carbon of the propionate substituent of the product. A tentative hypothesis is advanced to explain these and other experimental findings.