Iron catalyzed oxidative assembly of N-heteroaryl and aryl metal reagents using oxygen as an oxidant
作者:Kun Ming Liu、Lian Yan Liao、Xin Fang Duan
DOI:10.1039/c4cc08494b
日期:——
An equivalent amount of N-heteroaryl and aryl Grignard or lithium reagents, after mediation by an equivalent of titanate, was facilely coupled to furnish N-heteroaryl-aryl compounds under the catalysis of FeCl3/TMEDA at ambient temperature usingoxygen as an oxidant. Most of the common N-heteroaryls were all good candidates, and thus provided a general, green and pratical protocol for the flexible
Scope of regioselective Suzuki reactions in the synthesis of arylpyridines and benzylpyridines and subsequent intramolecular cyclizations to azafluorenes and azafluorenones
作者:Joydev K. Laha、Ketul V. Patel、Saima Saima、Surabhi Pandey、Ganesh Solanke、Vanya Vashisht
DOI:10.1039/c8nj02734j
日期:——
current investigation on regioselective Suzuki reactions of 2,3-dihalopyridines and 2-halo-3-halomethylpyridines yielded the unexplored synthesis of arylpyridines and benzylpyridines bearing synthetic handles for further functionalization. Indeed, the scope of intramolecularcyclizations of arylpyridines and benzylpyridines prepared in this study for the synthesis of azafluorenes and azafluorenones has been
arylmagnesium halides (phenylmagnesium chloride, mesitylmagnesium bromide, 4-(methoxycarbonyl)phenylmagnesium chloride and 4-cyanophenylmagnesium chloride) and halopyridines allowed the synthesis of substituted pyridines. Owing to the remarkably mild conditions used (often below 0°C), the reaction could be extended to the use of functionalized halopyridines, haloquinolines and halodiazines.
A simple metal-free, step-economic and selective access to pyridines from readily available substrates is reported, involving a flexible 4 A molecular sieves promoted Michael addition initiated domino three-component reaction between a 1,3-dicarbonyl, a Michael acceptor and a synthetic equivalent of ammonia.
Metal-Free Michael-Addition-Initiated Three-Component Reaction for the Regioselective Synthesis of Highly Functionalized Pyridines: Scope, Mechanistic Investigations and Applications
and completely regioselective three-componentsynthesis of highly functionalizedpyridines from 1,3-dicarbonyl derivatives and Michael acceptors has been achieved. Activated Michael acceptors, that is, β,γ-unsaturated α-oxo carbonyl derivatives, were utilized, allowing substitution at the 4-position and remarkable functional diversity at the 2-position of the pyridine ring. The scope and limitations