A radical cyclization strategy for the concise total synthesis of (±)-geissoschizine
摘要:
A short synthetic route to (+/-)-geissoschizine (1) was developed that features the construction of a Corynanthe-skeleton via radical cyclization of vinyl iodide, which was easily prepared by assembly of three fragments. New pentacyclic molecules formed by the radical cyclization were also reported. (C) 1997 Elsevier Science Ltd.
为了合成excelsinidines和mavacurans生物碱,研究了由KHMDS / I 2介导的(+)-geissochizine及其类似物的生物启发性氧化环化作用。应用于Geissoschizine时,N4-C16键的形成导致了Excelsinidines的核心。脂族氮的季铵化是进入马六甲聚糖核心(N1-C16键)所必需的。或者,通过α-氯内酰胺的分子内亲核取代合成17-或excelsinidine。
Bioinspired Oxidative Cyclization of the Geissoschizine Skeleton for the Total Synthesis of (−)-17-nor-Excelsinidine
作者:Maxime Jarret、Aurélien Tap、Cyrille Kouklovsky、Erwan Poupon、Laurent Evanno、Guillaume Vincent
DOI:10.1002/anie.201802610
日期:2018.9.17
report the first totalsynthesis of (−)‐17‐nor‐excelsinidine, a zwitterionic monoterpene indole alkaloid that displays an unusual N4−C16 connection. Inspired by the postulated biosynthesis, we explored an oxidative coupling approach from the geissoschizine framework to forge the key ammonium–acetate connection. Two strategies allowed us to achieve this goal, namely an intramolecular nucleophilic substitution
Collective Total Synthesis of Mavacuran Alkaloids through Intermolecular 1,4‐Addition of an Organolithium Reagent.
作者:Audrey Mauger、Maxime Jarret、Aurélien Tap、Rémi Perrin、Régis Guillot、Cyrille Kouklovsky、Vincent Gandon、Guillaume Vincent
DOI:10.1002/anie.202302461
日期:——
Intermolecular 1,4-addition of a functionalized vinyl lithium reagent to a readily accessible Michael acceptor enabled the synthesis of six mavacuran alkaloids with a highly strained pentacyclic cagelike framework. The chemo- and diastereoselectivity of the reaction were rationalized by DFT calculations. Dihydroxylation and pinacol rearrangement of the indole nucleus completed the first total syntheses
Organocatalytic Enantioselective Total Synthesis of (−)-Arboricine
作者:Martin J. Wanner、Rowan N. A. Boots、Bram Eradus、René de Gelder、Jan H. van Maarseveen、Henk Hiemstra
DOI:10.1021/ol900888e
日期:2009.6.18
The tetracyclic indole alkaloid (-)-arboricine has been prepared using an asymmetric organocatalytic Pictet-Spengler reaction as the key step followed by a diastereoselective Pd-catalyzed iodoalkene/enolate cyclization. The absolute stereochemistry was unequivocally proven by X-ray crystallographic analysis and appeared to be opposite to the published structure in the original paper.