Scheme 3. Proposal for the Observed Solvent-Dependent Chemoselectivity of Pyridyl Radicalsa.
aThe competition experiments were performed with [Ir(ppy)2(dtbbpy)]PF6 (1 mol %), Hantzsch ester (1.3 equiv), 2-bromo-6-methylpyridine (1 equiv), dimethylethylidene malonate (3 equiv), and isopropenyl acetate (3 equiv) in 2,2,2-trifluoroethanol (0.1 M) at 23 °C for 16 h.