Diastereoselective Photoreaction of Ir(III) Amine Complexes for Generation of New Multidentate Ligands in situ via a Postcoordinated Interligand-Coupling Strategy

The diastereoselective photoreactions of Ir(III)-amine and Ir(III)-diamine complexes are observed in the presence of O2.TheɅ-[Ir(pq)_(2)(R-mapy)](PF_(6))(pq is 2-phenylquinoline and mapy is 2-(1-aminoethyl)pyridine)diastereomer is dehydrogenatively oxidized into imine complexɅ-[Ir(pq)_(2)(mapy-2H)](PF_(6))at room temperature,while theɅ-[Ir(pq)_(2)(S-mapy)](PF_(6))diastereomer occurs interligand C—N cross-coupling reaction at 60℃,affording a new tetradentate complexɅ-[Ir(pq)(S-pqpe)](PF_(6))(pqpe is 2-phenyl-N-(1-pyridin-2-yl)ethyl-quinolin-8-amine).The identical cases are also observed in diamine complexesɅ-[Ir(pq)_(2)(R,R-chda)](PF_(6))(chda is 1,2-diaminocyclohexane),Ʌ-[Ir(pq)_(2)(R,S-chda)](PF_(6)),andɅ-[Ir(pq)_(2)(S,S-chda)](PF_(6)),where the R configuration ligand is dehydrogenatively oxidized into imine,while the S configuration is retentive and the bound nitrogen atom is coupling to the C8 of pq ligand,affordingɅ-[Ir(pq)_(2)(chdi)](PF_(6))(chdi is 1,2-diiminocyclohexane),Ʌ-[Ir(pq)(S-pqchim)](PF_(6))(pqchim is N-(2-iminocyclohexyl)-2-phenyl-quinolin-8-amine),andɅ-[Ir(S,S-pqchda)](PF_(6))(pqchda is N',N”-bis(2-phenylquinolin-8-yl)cyclohexane-1,2-diamine),respectively.These provide a new and useful protocol for the synthesis of multidentate ligands in situ via the postcoordinated interligand-coupling strategy under mild conditions.