Exploration of a Chiral Cobalt Catalyst for Visible‐Light‐Induced Enantioselective Radical Conjugate Addition. Issue 38 (7th August 2019) - Zhang, Kai
Abstract: 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. Abstract : Chiral octahedral complexes were prepared from earth‐abundant cobalt and chiral N4 ligands. One structurally well‐defined cobalt complex was an efficient chiral catalyst in visible‐light‐induced radical conjugated additions. Synthetically valued chiral ketones and 1, 4‐dicarbonyls were afforded in 47–>99 % yields (46 examples) with up to 97:3 e.r.