Copper-catalyzed aerobic oxidative esterification of acetophenones with alcohols using molecular oxygen has been developed to form a broad range of α-ketoesters in good yields. In addition to reporting scope and limitations of our new method, mechanism studies are reported that reveal that the carbonyl oxygen in the ester mainly originated from dioxygen.

Fe-catalyzed aerobic oxidative esterifications of arylacetonitriles with alcohols, tri alkoxsilanes, silicate esters, or borate esters have been developed. The acyl groups which were in situ generated via chemoselective C(CO)-CN bond cleavage were directly used as electrophiles, leading to corresponding aryl esters in good to excellent yields under molecular oxygen when attacked by alcohols or alcohol surrogates. Dioxygen serves as both oxidant and reactant in this protocol. The reaction has a very broad substrate scope. Cheap starting materials as well as environmentally benign and inexpensive iron catalyst and ideal oxidant O2 feature this transformation and make it a practical and sustainable protocol to afford esters.

An iron-catalyzed aerobic oxidative amidation of aryl acetonitriles to afford amides is achieved using urea as a convenient nitrogen source.

Cu-Catalyzed Aerobic Oxidative Esterification of Acetophenones with Alcohols to -Ketoesters. -The reaction of various aryl and hetarylmethylketones with aliphatic and benzylic alcohols as well as arylethyl alcohol derivatives or even cholesterol to -ketoesters is described. -(XU, X.; DING, W.; LIN, Y.; SONG*, Q.; Org. Lett. 17 (2015) 3, 516-519, http://dx.