One-Pot Transformation of Hypervalent Iodines into Diversified Phenoxazine Analogues as Promising Photocatalysts.

A facile and efficient quinoline-fused 4-benzo[][1,4]oxazine has been successfully fabricated through an oxidative -arylation, Pd-catalyzed double -arylation of 4-hydroxyquinoline derivatives and trivalent aryl iodides. Diversified fused heterocycles could be easily constructed in overall high isolated yields with great substrate scope. The afforded heteroatom-"doped" phenoxazine demonstrated high molar absorptivities and excellent stability and redox reversibility.

Copper-Catalyzed Aerobic 6-Endo-Trig Cyclization of β,γ-Unsaturated Hydrazones for the Divergent Synthesis of Dihydropyridazines and Pyridazines.

A divergent synthetic strategy to 1,6-dihydropyridazines and pyridazines through Cu(II)-catalyzed controllable aerobic 6-endo-trig cyclization was developed. The selectivity can be rationally tuned via the judicious choice of reaction solvent. It was found that the 1,6-dihydropyridazines were obtained in moderate to high yields with CHCN as the reaction solvent, whereas employment of AcOH directly afforded pyridazines in up to 92% yields, probably arising from the oxidation of the in situ generated 1,6-dihydropyridazines.

N-Heterocyclic Carbene (NHC) Organocatalytic One-Pot Reaction for the Enantioselective Synthesis of Fluoromethylated Chromenones.

An efficient carbene organocatalyzed route to enantioenriched chromenones, bearing one tri- or difluoromethylated stereogenic center in the β position of the carbonyl group, from o-allyloxybenzaldehydes is described. The one-pot transition-metal-free transformation exhibits a broad substrate scope and excellent enantioselectivity.