A fluorescence probe based on cinnamyl pyrazoline was developed and synthesized.

No abstract

The asymmetric unit of the title compound, C10H7F3O4, contains two independent molecules. In one of the molecules, the F atoms of the rifluoromethyl group are disordered over two positions with site occupation factors 0.231 (11)/0.769 (11). The intramolecular C—H...O hydrogen bond results in the formation of a planar five‐membered ring, which is oriented at a dihedral angle of 4.24 (3)° with respect to the six‐membered ring. In the crystal structure, C—H...F and O—H...O hydrogen bonds link the molecules.

A novel organocatalytic [3+2] annulation/oxidative aromatization reaction of enals with 2-halophenols or β-naphthols is reported. This process enables chemo- and regioselective access to 2-arylbenzofuran-3-carbaldehydes without the use of transition metals or strong oxidants. Preliminary mechanistic studies reveal that an unprecedented, organocatalytic, direct α-arylation pathway is involved.