Insights into the mechanistic and synthetic aspects of the Mo/P-catalyzed oxidation of N-heterocycles
作者:Oleg V. Larionov、David Stephens、Adelphe M. Mfuh、Hadi D. Arman、Anastasia S. Naumova、Gabriel Chavez、Behije Skenderi
DOI:10.1039/c4ob00115j
日期:——
Mechanistic and synthetic studies of the Mo/P-catalyzed N-oxidation of N-heterocycles with hydrogen peroxide shed light on the role and nature of the catalytically active species.
anes are formed from imidazole or thiazole N-oxide, 1,1-difluorostyrene, and an alcohol, amine, or water in a three-component reaction, which probably occurs via 1,3-dipolar cycloaddition. The whole process is a novel method for functionalization of a heterocyclic ring in a position originally occupied by hydrogen. Preliminary experiments show that it occurs for 6-membered N-oxides as well.
A novel metal-free synthesis of thiazole-substituted α-hydroxy carbonyl compounds and 2-alkenylthiazoles from thiazole N-oxides and olefins
作者:Hui Li、Juan Zhang、Yanqiu Zhang、Jiayi Wang、Gonghua Song
DOI:10.1016/j.tetlet.2019.05.053
日期:2019.12
A metal-free and highly atom-economic synthesis of thiazole-substituted α-hydroxy carbonyl compounds has been developed. Catalyzed by 5 mol% of p-toluenesulfonic acid (TsOH), a variety of thiazole-substituted α-hydroxy carbonyl compounds were obtained in moderate to good yields via 1,3-dipolar cycloaddition of thiazole N-oxides with olefins, followed by a ring-opening reaction. Furthermore, the corresponding
Synthesis of 2-Sulfonylthiazoles via Heteroaryl C–H Sulfonylation of Thiazole N-Oxides
作者:Hyun-Suk Um、Woong Sik Shin、Kyu Jin Son、Chulbom Lee
DOI:10.1055/a-2059-3168
日期:——
Described here is an efficient method for the modular synthesis of 2-sulfonylthiazole derivatives via heteroaryl C–H sulfonylation. The protocol is composed of two stages involving O-activation of thiazole N-oxides and nucleophilic addition of a sulfinate, which induces N(3)-deoxygenation and C(2)-sulfonylation. The vicarious substitution is performed most effectively by using 4-methoxybenzoyl chloride