The intramolecular addition of an aryl radical to a pyridine provides a short entry to toddaquinoline
作者:David C. Harrowven、Michael I.T. Nunn
DOI:10.1016/s0040-4039(98)01187-3
日期:1998.8
The paper describes a synthetic approach to toddaquinoline, an unusual alkaloid from the root bark of FormosanToddaliaasiatica. Key steps are a cis-selective Wittig coupling and a trialkyltin mediated, intramolecular cyclisation of an aryl radical to C-6 of a pyridine.
A total synthesis of toddaquinoline exposes a dual role for cobalt in radical additions to pyridines
作者:David C Harrowven、Michael I.T Nunn、Nigel J Blumire、David R Fenwick
DOI:10.1016/s0040-4039(00)01119-9
日期:2000.8
This paper describes the first total synthesis of toddaquinoline, an alkaloid from the root bark of FormosanToddaliaasiatica. Importantly, the synthesis has exposed a dichotomy in radical reactions mediated by tin and cobalt(I) that involve additions to pyridines. Our observations suggest that cobalt plays a dual role in such reactions: firstly initiating homolysis of the carbon to halogen bond,
The first total synthesis of toddaquinoline, an alkaloid from Toddalia asiatica
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 mediatedradical cyclisation