An efficient Ru(II)-catalyzed hydroarylation of maleimides with ready-stock aryl carboxylic acids has been developed based on weak carboxylate-directed ortho-C-H alkylation and concomitant decarboxylation processes, fabricating 3-aryl succinimides, a recurrent scaffold in drug molecules, in high yields (up to 97%). The protocol features operational simplicity, avoids the need for precious metal additives/oxidants, and offers broad substrate scope with formal meta- and para-selectivities. It represents the first example of Ru(II)-catalyzed direct arylation of maleimides with unbiased benzoic acids.

A visible light-induced (blue LED) radical cascade has been devised to effect selenylative spirocyclization of N-aryl alkynamides at room temperature under oxygen atmosphere and without the aid of external photocatalyst. The protocol is operationally simple, scalable, and offers clean synthesis of 3-selenospiro[4,5]trienones in high yields (up to 92%). A novel spiro-ring-opening strategy has also been accomplished to access fully substituted acryl amides.

An efficient copper-catalyzed/-mediated and 8-aminoquinoline-assisted arylselenylation of inert C-H bonds of (hetero)arenes with readily available diselenides has been reported. The reaction is scalable and tolerates a wide spectrum of functional groups to deliver diarylselenides in very high yields (up to 98%). Application of this methodology to the facile synthesis of thiophene-fused selenochromone was demonstrated.

A general protocol for direct chalcogenation of inert C-H bonds of (hetero)aromatic carboxylic acids is developed with a ruthenium(II) catalyst using readily available starting materials, offering densely substituted ortho-chalcogenyl aromatic acids in high yields (up to 96%). The strategy avoids the installation of an external directing group, use of metallic oxidants, and features operational simplicity with ample substrate scope. Synthetic application en route to biologically important chalcogenoxanthones is also demonstrated. This work represents the first example of ruthenium(II)-catalyzed direct C-H chalcogenation of benzoic acids.

The unconventional nucleophilic reactivity of maleimides, innate electrophiles, has been realized under Ru(II)-catalysis such that exposure to electrophiles delivered products of C-H chalcogenation and amidation in good yields (up to 94%). This protocol features mild conditions and operational simplicity with broad substrate scope, uses an inexpensive and air-stable catalyst, and also represents the first example of Ru(II) catalyzed C-H selenylation of alkenes.