Synthesis of 2-Aryl-4H-thiochromen-4-one Derivatives via a Cross-Coupling Reaction

A concise and efficient cross-coupling synthetic strategy has been developed to construct 2-aryl-4H-thiochromen-4-one derivatives from 2-sulfinyl-thiochromones and arylboronic acids. This reaction proceeds via a catalyst system of Lewis acid and palladium(II) combined with XPhos as an optimal ligand in moderate to good yields. Besides, this flexible methodology provides a wide scope for the synthesis of different functionally substituted thiochromone scaffolds and can be further exploited to construct diverse thioflavone libraries for pharmaceutical research.

Synthesis of Substituted 4 H-Thiochromen-4-imines via Copper-Catalyzed Cyclization Cascades of o-Bromobenzothioamides with Terminal Alkynes

A series of ( E)- N-aryl-4 H-thiochromen-4-imines has been conveniently obtained through a cascade reaction between o-bromobenzothioamides and terminal alkynes. This novel approach probably involved an initial generation of benzothietane-2-imine intermidates via an intramolecular Ullmann reaction under CuI/L-proline cocatalysis and alkaline conditions followed by imine alkynylation, ring opening, and cyclization sequences to provide the unexpected 4 H-thiochromen-4-imines rather than isothiochromans.

Synthetic quinolone signal analogues inhibiting the virulence factor elastase of Pseudomonas aeruginosa

We explore the chemical space of Pseudomonas quinolone signal analogs as privileged structures and report the discovery of a thioquinolone as a potent inhibitor of the important virulence factor elastase of the human pathogen Pseudomonas aeruginosa. We provide evidence that the derivative binds to the active site zinc of elastase and additionally acts as a fluorescent zinc sensor.