Energy Transfer (EnT)-Mediated Stereoselective Aryl-Heterofunctionalization of Unactivated Alkynes via Radical Rearrangement.

In this study, we present a novel catalyst-free energy transfer mediated radical rearrangement strategy for the aryl-heterofunctionalization of unactivated alkynes, leading to the synthesis of polyfunctional olefins with exceptional stereoselectivity. This innovative approach, driven by visible light, exemplifies green chemistry principles by eliminating the reliance on transition metals, external oxidants, and photocatalysts. The broad applicability of our method is demonstrated through the successful synthesis of a diverse array of compounds, including vinyl sulfones, vinyl selenides, and vinyl sulfides.

N-(2,4-Difluoro-phen-yl)-5-methyl-1,2-oxazole-4-carboxamide hemihydrate.

In the title compound, C(11)H(8)F(2)N(2)O(2)·0.5H(2)O, the dihedral angle between the benzene and isoxazole rings is 8.08 (3)°.

5-Methyl-N-[2-(trifluoro-meth-yl)phen-yl]isoxazole-4-carboxamide.

In the title compound, C(12)H(9)F(3)N(2)O(2), the benzene ring is nearly perpendicular to the isoxazole ring, making a dihedral angle of 82.97 (2)°. In the crystal, mol-ecules are linked by N-H⋯O hydrogen bonds into a supra-molecular chain running along the c axis.