Highly chemo- and regioselective allylic substitution with tautomerizable heteroarenes
Tautomerizable heteroarenes, bearing multiple interconvertible nucleophilic centers exhibit high chemo- and regioselective allylation irrespective of allylating agents used under Pd-catalysis. The achieved selectivity may be attributed to the dominant lactam form of heteroarenes and Pd-catalyzed intramolecular allylic substitution. A generalized green protocol for chemo- and regioselective allylation of biologically relevant heteroarenes with allyl alcohols in dimethyl carbonate (DMC) as solvent was developed. Excellent selectivity was observed during intermolecular competition study demonstrating the differential nucleophilicity of tautomerizable heteroarenes and differential allyl palladium forming ability of a variety of allyl alcohols.