Rhodium-Catalyzed MCRs via Onium Ylide Intermediates

1 Rhodium-Catalyzed MCRs via Onium Ylide Intermediates 

SCHEME 3.56 Synthesis of benzothiazoles via Cu-catalyzed coupling of 2-iodoanilines, carbon disulfide, and secondary amines. 

40 examples, 33-91% SCHEME 3.57 Au(I)-catalyzed oxidative oxyarylation of alkenes. 

SCHEME 3.58 Rh-catalyzed insertion of carbene species into X—H bonds. 

1 Rhodium-Catalyzed Reactions of Oxonium YUde Intermediates Hu et al. [158] reported the preparation of a,p-dihydroxyl and a-aUcoxy-p-aUcylamino acid derivatives through a rhodium-catalyzed three-component reaction starting from a diazo compound 108, an alcohol 109, and different electrophiles such as aldehydes 110 or imines 111. The reaction proceeds through formation of a Rh-oxonium ylide species, generated from the diazo compound 108 and the alcohol 109, which is subsequently trapped by the electrophile. Employing different Rh(II) catalysts, erythro/threo mixtures of a,p-dihydroxyl and a-alkoxy-p-alkylamino esters 

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