Synthesis of substituted β-carbolines via gold(III)-catalyzed cycloisomerization of N-propargylamides
作者:Guido Verniest、Dylan England、Norbert De Kimpe、Albert Padwa
DOI:10.1016/j.tet.2009.10.033
日期:2010.2
Indole-substituted N-propargylamides undergo a gold(III)-catalyzed cyclization to give oxazoles or beta-carbolinones, depending on the Substitution pattern at the amide nitrogen. Secondary amides furnished oxazoles via a 5-exo-dig cyclization, while tertiary indole-2-carboxamides cycloisomerized to give 2,9-dihydro-beta-carbolin-1-ones upon treatment with catalytic amounts of gold(III) chloride. An optimized procedure was developed to prepare several new N-benzyl-beta-carbolinones as well as the corresponding beta-carbolines, which are of interest as core structures found in various natural products such as the harman, ervolanine, and lavendamycin class of alkaloids. (C) 2009 Elsevier Ltd. All rights reserved.
Heteroaryl Cross-Coupling as an Entry toward the Synthesis of Lavendamycin Analogues: A Model Study
作者:Guido Verniest、Xingpo Wang、Norbert De Kimpe、Albert Padwa
DOI:10.1021/jo902287t
日期:2010.1.15
prepared via the palladium(0)-catalyzed cross-coupling reaction of various 2-haloheteroaromatics with 2-stannylated pyridines and quinolines. Using the Stillereaction, 2-bromo substituted quinolines and 1-bromoisoquinolines were found to undergo efficient coupling with 2-pyridinylstannanes to provide unsymmetrical heterobiaryl derivatives. While the Stillereaction using the reverse coupling partners