Hydroalkoxylation of Enamides Catalyzed by N-Heteroarenium Iodides

A facile and novel N-heteroarenium iodide-catalyzed hydroalkoxylation of enamides has been described. The protocol provides easy access to N,O-acetals, which proved to be a versatile synthetic synthon. The hydrosulfonylation, hydroamination, and hydrophosphorylation products of enamide could be indirectly provided from N,O-acetals. The reaction mechanism was further investigated, which indicated that the hydroalkoxylation of enamides was driven by weak coordination between enamide and the contact ion pair of N-heteroarenium iodide.

Tandem Ring-Contraction/Regioselective C-H Iodination Reaction of Pyridinium Salts

A facile route for direct access to the 4-iodopyrrole-2-carbaldehydes from pyridinium salts has been successfully developed, which undergoes cascade pyrrole-2-carbaldehydes construction/selective C4 position iodination process. Using Na₂S₂O₈ as an oxidant and readily available sodium iodide as an iodine source, a variety of 4-iodopyrrole-2-carbaldehydes were obtained in good to excellent yields. Atom- and step-economy, good functional group tolerance, high regioselectivity, as well as mild conditions entail this transformation an alternative strategy for enriching pyrroles library.

Direct C-H Sulfonylimination of Pyridinium Salts

A direct pyridinium C-H sulfonylimination has been developed for the synthesis of sulfonyl iminopyridine derivatives with high efficiency. This transformation features the direct and efficient formation of a C═N bond with a high functional group tolerance under metal-free conditions. The spectroscopic properties potentially enable these sulfonyl iminopyridine compounds to be useful new emitting materials.

Decarboxylative C–H alkylation of heteroarenes by copper catalysis

A copper-catalyzed decarboxylative C–H alkylation of heteroarenes with alkyl carboxylic acids has been realized.