Cross-metathesis reactions of α,β-unsaturated sulfones and sulfoxides in the presence of molybdenum and ruthenium pre-catalysts were tested. A selective metahesis reaction was achieved between functionalized terminalolefins and vinyl sulfones by using the ‘second generation’ ruthenium catalysts 1c–h while the highly active Schrock catalyst 1b was found to be functional group incompatible with vinyl
A base-controlled regioselective synthesis of allyl and vinyl phenyl sulfones
作者:Dibyendu Dana、Anibal R. Davalos、Gopal Subramaniam、Nisar Afzal、William H. Hersh、Sanjai Kumar
DOI:10.1016/j.tetlet.2013.03.056
日期:2013.5
2-arylacetaldehydes in the presence of a catalytic excess of sodium hydride (1.1 equiv) yields allylphenylsulfones in excellent yield under mild reaction conditions. In contrast, when less than 1 equiv of sodium hydride (0.90 equiv) is used, the corresponding vinyl phenylsulfones are obtained exclusively. The vinyl phenylsulfones can be completely converted to allylphenylsulfones with only 0.2 equiv
Nickel-Catalyzed Direct Sulfonylation of Styrenes and Unactivated Aliphatic Alkenes with Sulfonyl Chlorides
作者:Wei-Hao Rao、Ying-Ge Li、Li−Li Jiang、Chang Gao、Yi-Zhuo Wang、Jia-Fan Liu、Fu-Yu Zhou、Guo-Dong Zou、Xinhua Cao
DOI:10.1021/acs.joc.4c00094
日期:2024.7.19
with sulfonylchlorides has been developed using 1,10-phenanthroline-5,6-dione as the ligand. Unactivated alkenes and styrenes including 1,1-, 1,2-disubstituted alkenes can be subjected to the protocol, and a wide range of vinyl sulfones was obtained in high to excellent yields with good functional group compatibility. Notably, the process did not allow the desulfonylation of sulfonylchloride or chlorosulfonylation
The design, synthesis, stability, and catalytic activity of nitro-substituted Hoveyda-Grubbs metathesis catalysts are described. The highly active and stable meta- and para-substituted complexes are attractive from a practical point of view. These catalysts operate in very mild conditions and can be successfully applied in various types of metathesis [ring-closing metathesis, cross-metathesis (CM), and enyne metathesis]. Although the presence of a NO2 group leads to catalysts that are dramatically more active than both the second-generation Grubbs's catalyst and the phosphine-free Hoveyda's carbene, enhancement of reactivity is somewhat lower than that observed for a sterically activated Hoveyda-Grubbs catalyst. Attempts to combine two modes of activation, steric and electronic, result in severely decreasing a catalyst's stability. The present findings illustrate that different Ru catalysts turned out to be optimal for different applications. Whereas phosphine-free carbenes are catalysts of choice for CM of various electron-deficient substrates, they exhibit lower reactivity in the formation of tetrasubstituted double bonds. This demonstrates that no single catalyst outperforms all others in all possible applications.
Chloro-substituted Hoveyda–Grubbs ruthenium carbene: Investigation of electronic effects
作者:Roberta Ettari、Nicola Micale
DOI:10.1016/j.jorganchem.2007.04.017
日期:2007.7
A series of applications of cross and ring-closing metathesis has been made to investigate the application profile of the chloro-substituted Hoveyda-Grubbs ruthenium carbene in order to evaluate electronic effects resulting from the introduction of a chlorine atom to the isopropoxy moiety of its parent catalyst. (c) 2007 Elsevier B.V.. All rights reserved.