作者:David C Harrowven、Michael I.T Nunn、Nigel J Blumire、David R Fenwick
DOI:10.1016/s0040-4020(01)00336-2
日期:2001.5
cobalt(I) mediated radial cyclisation to a pyridine. Cobalt appears to play a dual role in the reaction, firstly initialising homolysis of the carbon to halogen bond then acting as a Lewis acid to promote cyclisation to C-6. Other approaches examined are also outlined. These include a photocyclisation of an azastilbene; a cyclisation induced by halogen to metal exchange and a tin mediated radical cyclisation
该论文描述了首次从头皮中提取的生物碱-托达喹啉(toddaquinoline)。关键步骤是钴(I)介导的向吡啶的径向环化。钴似乎在反应中起双重作用,首先是启动碳与卤素键的均裂,然后充当路易斯酸以促进环化成C-6。还概述了其他检查的方法。这些包括氮杂环丁烯的光环化;卤素与金属的交换以及锡介导的自由基环化引起的环化。