Rhodium(I)-catalyzed one-pot synthesis of dialkyl ketones from methanol and alkenes through directed sp~3 C-H bond activation of N-methylamine

摘要

The hydroacylation of methanol with alkenes was developed using a catalytic system consisting of Rh(I), 2-amino-4-picoline and benzoic acid; the reaction is speculated to occur by the initial iV-methylation of 2-amino-4-picoline with methanol, and the subsequent dehydrogenation of the resulting N-methylamine, followed by double chelation-assisted hydroimination of alkene with the inline to give dialkyl ketones after hydrolysis.rnThe activation of C-H bonds by transition metal complexes is a current interest in organic synthesis. In particular, hydroacylation of alkenes or alkynes with aldehydes to produce ketones is quite interesting in terms of atom economy. We have successfully developed a Rh(I)-catalyzed chelation-assisted hydroacylation with a co-catalyst system consisting of rhodium(I) complex and 2-amino-3-picoline as an organic catalyst. This protocol was further applied to the synthesis of ketones from Primary alcohols instead of aldehvdes.