Suvajit Koley

Palladium catalyzed oxidative coupling of α-enolic dithioesters: a new entry to 3,4,5-trisubstituted 1,2-dithioles via a double activation strategy.

An operationally simple, facile, and convenient one-pot straightforward method for the construction of 3,4,5-trisubstituted 1,2-dithioles has been explored and developed via palladium catalyzed self-coupling of α-enolic dithioesters for the first time. Pd(0) efficiently catalyzes the activation and cleavage of S-H and C-S bonds to achieve cascade coupling, which results in the concomitant formation of new S-S and C-C bonds. Optimization data, substrate scope, and mechanistic insights are discussed.

CuSO4–D-glucose, an inexpensive and eco-efficient catalytic system: direct access to diverse quinolines through modified Friedländer approach involving SNAr/reduction/annulation cascade in one pot

A highly efficient and scalable multicomponent domino reaction for the synthesis of functionalized/annulated quinolines is devised directly from 2-bromoaromatic aldehydes/ketones in H2O–EtOH mixture for the first time. The key to this reaction is the use of an air-stable, eco-efficient and inexpensive CuSO4–D-glucose catalyst system, which is able to catalyze multiple transformations in one pot. The approach is carbon-economic and relies on sequential SNAr/reduction/Friedlander annulation steps, forming C–C and C–N bonds by cleavage of the Csp2–Br bond in a single synthetic operation. The reaction has a broad substrate scope and affords products in good to excellent yields.

Cross-Dehydrogenating Coupling of Aldehydes with Amines/R-OTBS Ethers by Visible-Light Photoredox Catalysis: Synthesis of Amides, Esters, and Ureas

A straightforward synthesis of amides, ureas, and esters is reported by visible-light cross-dehydrogenating coupling (CDC) of aldehydes (or amine carbaldehydes) and amines/R-OTBS ethers by photoredox catalysis. The reaction is found to be general and high yielding. A plausible mechanistic pathway has been proposed for these transformations and is supported by appropriate controlled experiments.