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,
Deaminative ring contraction for the synthesis of polycyclic heteroaromatics: a concise total synthesis of toddaquinoline
作者:Emily K. Kirkeby、Zachary T. Schwartz、Myles A. Lovasz、Andrew G. Roberts
DOI:10.1039/d3sc03936f
日期:——
A concise strategy to prepare polycyclic heteroaromatics involving a deaminative contraction cascade is detailed. The efficient deaminative ring contraction involves the in situ methylation of a biaryl-linked dihydroazepine to form a cyclic ammonium cation that undergoes a base-induced [1,2]-Stevens rearrangement/dehydroamination sequence. The presence of pseudosymmetry guides the retrosynthetic analysis