Exploration of a Chiral Cobalt Catalyst for Visible‐Light‐Induced Enantioselective Radical Conjugate Addition

Chiral catalysts tolerating photochemical reactions are in great demand for the vast development of visible‐light‐induced asymmetric synthesis. Now, chiral octahedral complexes based on earth‐abundant metal and chiral N₄ ligands are reported. One well‐defined chiral Co^II‐complex is shown to be an efficient catalyst in the visible‐light‐induced conjugated addition of enones by alkyl and acyl radicals, providing synthetically valued chiral ketones and 1,4‐dicarbonyls in 47–>99 % yields with up to 97:3 e.r.     

Rhodium‐Catalyzed Enantioselective Reductive Arylation: Convenient Access to 3,3‐Disubstituted Oxindoles

A rhodium‐Josiphos(L*) catalyzed enantioselective intramolecular hydroarylation reaction is described. The reductive cyclization of o ‐bromoaniline‐derived acrylamides provides convenient access to 3,3‐disubstituted oxindoles in good yields and with excellent enantioselectivity across a range of substrates. We propose that the key cyclization proceeds via a rhodium(III) intermediate. Overall, this method represents an unusual mode of reactivity for rhodium catalysis and is complementary to palladium(0)‐catalyzed α‐arylation methods.