Ruthenium Catalyzed C-H Selenylation And Thiolation Of Aryl(Alkyl) Amide(Ester)

Benzamides,arylacetamides and aryl acetate compounds are very important chemical intermediates which could be widely applicated in organic synthesis.Furthermore,they also displayed multitude of bioactivities in natural products and drugs.For example,the penicillin G,anthranilic acid and arylacetic acid derivatives are valuable antibacterial agents and NSAIDs(nonsteroidal anti-inflammatory drugs)which are widely used in clinical medicine.There fore,the development of novel synthetic methods for the site-selective modification of aryl(alkanoic)acid derivatives has attracted considerable interest.This dissertation focuses on cost-effective ruthenium(II)-catalyzed ortho-chalcogenations of aryl(alkyl)amide(ester)with readily available diaryl diselenides and diaryl disulfides via C-H bond activation process.After a series of catalyst,solvent and additive screen,we developed a new chalcogenation method.These methods feather mild reactions,atom-and step economic fashion along with widely functional groups tolerance.Furthermore,on the basis of the preliminary mechanistic studies,a plausible reaction mechanism for the ruthenium(II)-catalyzed C–H chalcogenations of arylamides and arylacetic amides was il ustrated.Chapter 1.Ruthenium-catalyzed C-H selenylations of benzamides.A wide range of differently substituted arylamides and diaryl diselenides was efficiently converted under this robust ruthenium catalysis manifold,providing mono-selenylated products in good to excellent yields.Notably,the amide group could be further transformed into synthetcially useful aldehyde,carboxylate acid,tetrazole and phosphite derivatives in a step-economical fashion under mild reaction conditions.Chapter 2.Ruthenium catalyzed C–H selenylations of aryl acetic amides and esters.An efficient ruthenium-catalyzed direct C-H selenylations of aryl acetic amides and esters have been achieved via distal weakly coordination.These reactions were characterized with good functional group tolerance,scalable and high regioselectivity,delivering a series of unsymmetrical diaryl selenides and diaryl sulfides in good yields,thus provided an economical,convenient and green synthetic route for the structural modification of aryl acid derivatives.