Lithiation and functionalization of 1-alkynylimidazoles at the 2-position
摘要:
Functionalization reactions of 1-alkynylimidazoles involving the formation of their 2-lithio derivatives followed by addition of various electrophiles are presented. This allows access to previously unreported 1,2-dialkynylimidazoles via 1-alkynyl-2-iodoimidazoles. The use of an aldehyde or sulfonimine electrophiles allows the direct formation of bicyclic ring systems. (C) 2009 Elsevier Ltd. All rights reserved.
Electrophilic Cyclization of<i>N</i>-Alkynyl-2-(organochalcogen)imidazoles: An Alternative Access to Imidazo[2,1-<i>b</i>]chalcogenazoles
作者:Tamíris B. Grimaldi、Benhur Godoi、Juliano A. Roehrs、Adriane Sperança、Gilson Zeni
DOI:10.1002/ejoc.201201692
日期:2013.5
multifunctional imidazo[2,1-b]chalcogenazoles through electrophiliccyclization of N-alkynyl-2-(organochalcogen)imidazoles. The cyclization reaction proceeded cleanly and smoothly under mild reaction conditions in the presence of air. The methodology was highly regioselective: In a competition between the chalcogen and oxygen atoms, only S-, and Se-heterocycles were obtained. The resulting imidazo[2,1-b]chalcogenazoles
Three-Step One-Pot Synthesis of Imidazo[2,1-b]chalcogenazoles via Intramolecular Cyclization of N-Alkynylimidazoles
作者:Juliano Alex Roehrs、Renan P. Pistoia、Davi F. Back、Gilson Zeni
DOI:10.1002/adsc.201200075
日期:2012.6.18
Imidazo‐chalcogenazoles are easily accessible from the corresponding N‐alkynylimidazoles by a three‐step, one‐pot chalcogenation reaction. The generality of this reaction has been established with various substituted N‐alkynylimidazoles as well as elemental chalcogens. By accessing the key intermediate 2‐chalcogenolate‐N‐alkynylimidazole it was also possible to prepare dichalcogenide derivatives.
Preparation of (<i>Z</i>)-α,β-Disubstituted Enamides via Palladium-Catalyzed Addition of Boronic Acids to Ynamides
作者:Yuanfa Yang、Lina Wang、Fang Zhang、Gangguo Zhu
DOI:10.1021/jo501894j
日期:2014.10.3
Pd-catalyzed, highly regio- and stereoselective addition of boronic acids to ynamides has been realized. This protocol generates (Z)-α,β-disubstituted enamides in high yields with excellent regio- and stereoselectivity under the mild reaction conditions, thereby providing a good complementary method for the diverse synthesis of multifunctional enamides. A wide collection of functional groups are found
Phenylethynyl and styryl derivatives of imidazole and fused ring heterocycles
申请人:——
公开号:US20020128263A1
公开(公告)日:2002-09-12
This invention relates to a compound and the use of the compound of the formula
1
wherein R
1
, R
2
, R
3
, R
4
and R
5
are as defined in the description, A signifies —CH═CH— or —C≡C—; and B signifies
2
wherein R
6
to R
26
, X and Y are as defined in the specification or a pharmaceutically acceptable salt thereof, for use in pharmaceutical compositions for the treatment or prevention of mGluR5 receptor mediated disorders.
The couplingreaction of imidazoles and pyrazoles with bromoacetylenes has efficiently been carried out under ligand-free conditions in the presence of copper(II) oxide as the catalyst using potassium hydroxide in 1,4-dioxane at 80 ˚C. The method is a simpler access to N-alk-1-ynyl- and/or N-(2-bromovinyl)-substituted heteroarenes. couplingreaction - ligand-free conditions - copper(II) oxide - N-alkynylheteroarene