Base-Promoted β-C(sp3)–H Functionalization of Enaminones: An Approach to Polysubstituted Pyridines
摘要:
A convenient "one-pot" base-promoted synthesis of polysubstituted pyridines from 1-arylethylamines and ynones through the direct beta-C(sp(3))-H functionalization of enaminones under metal-free conditions has been developed. An intermolecular Michael addition reaction and an intramolecular condensation were involved in this procedure, which features high regioselectivity; high efficiency, and environmental friendliness. Various polysubstituted pyridines were provided in up to 92% yield for 34 examples.
Silylated azolium salts and their applications in the synthesis of azolines and β-enaminoketones bearing allyl-, vinyl-, and acylsilane or α-silylketone units
作者:Ana M. González-Nogal、Mariola Calle
DOI:10.1016/j.tet.2009.01.114
日期:2009.7
Differently silylated 3- or 4-isoxazolines and 3-pyrazolines, bearing versatile vinyl- or allylsilane moieties in various positions of the heterocyclic system, have been synthesized starting from new silylazolium salts by reduction with metal complex hydrides or alkylation with organolithium reagents. On the other hand, the reductive ring-opening of silylated isoxazolium salts with lithium dimethylcuprate