An efficient synthetic route for the preparation of louisianins C and D was developed starting with the commercially available 4-cyanopyridine. Louisianins C and D were synthesized in seven steps and with overall yields 22% and 20%, respectively, following a novel cyclization-decarboxylation sequence involving 4-bromo-6,7-dihydrocyclopenta[c]pyridin-5-one as the key intermediate. (C) 2008 Elsevier Ltd. All rights reserved.
A Pyridine–Pyridine Cross‐Coupling Reaction via Dearomatized Radical Intermediates
作者:J. Luke Koniarczyk、Jacob W. Greenwood、Juan V. Alegre‐Requena、Robert S. Paton、Andrew McNally
DOI:10.1002/anie.201906267
日期:2019.10.14
and cyanopyridines using B2 pin2 as an electron-transfer reagent. Complete regio- and cross-selectivity are observed when forming a range of valuable 2,4'-bipyridines. Phosphonium salts were found to be the only viable radical precursors in this process, and mechanistic studies indicate that the process does not proceed through a Minisci-type coupling involving a pyridyl radical. Instead, a radical-radical