Asymmetric Heck cyclization route to indolizidine and azaazulene alkaloids: synthesis of (+)-5-epiindolizidine 167B and indolizidine 223AB
摘要:
Asymmetric intramolecular Heck cyclization of endocyclic enamides occurs at room temperature to give indoloizidine and azaazulene ring systems in up to 86% enantiomeric excess. A synthesis of (+)-epiindolizidine 167B and formal synthesis of 5E,9Z-indolizidine 223AB is described. (C) 2001 Elsevier Science Ltd. All rights reserved.
Regiocontrolled synthesis of (hetero)aryl and alkenyl dehydropyrrolidines, dehydropiperidines and azepenes by Ru-catalyzed, heteroatom-directed α-C–H activation/cross-coupling of cyclic enamides with boronic acids
作者:Timothy K. Beng、Spencer Langevin、Hannah Braunstein、Monique Khim
DOI:10.1039/c5ob02263k
日期:——
The synthesis of α-aryl and alkenyl pyrrolidine-, piperidine-, and azepane derivatives, through the intermediacy of cyclic enamides is described. The desired outcome is achieved through ruthenium-catalyzed, site-selective sp2 C–H activation/cross-coupling with aryl and alkenylboronicacids. The regioselectivity (α-sp2vs. α-sp3vs. β-sp2 C–H functionalization) is governed by the rate differences between
Iridium-catalyzed α-alkynylation of cyclic nonaromatic eneformamides: application to the synthesis of azapolycyclic architectures
作者:Timothy K. Beng、Francine Wanjiku
DOI:10.1039/c9nj00003h
日期:——
A regioselective and chelation-assisted dehydrogenative alkynylation of cyclic nonaromatic eneformamides with terminal alkynes, under iridium catalysis, is described.