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This research presents an original method for synthesizing styrylfurans using N-heterocyclic carbenes (NHCs) and Brønsted acid catalysis. By exploiting 2,4-dioxoesters as conjugated 1,3-dicarbonyls, we have developed a technique allowing the efficient formation of highly functionalized styrylfurans with interesting photochemical properties, through a NHC-catalyzed cross-benzoin reaction followed by a Brønsted acid-driven Paal-Knorr-like condensation. This approach permits the integration of various substituents on the furan ring, with preliminary biological studies indicating potential as fluorescent dyes.

A new and unprecedented stereoselective synthetic approach to δ-oxoesters derivatives from readily available starting materials has been developed. This method, catalyzed by N-heterocyclic carbene, involves an annulation-deoxalation reaction of alkynyl aldehydes with 2,4-diketoesters and proceeds via the chiral α,β-unsaturated acylazolium intermediates. The annulation includes the in situ formation of dihydropyranones, which undergo ring-opening methanolysis with Lewis acid activation, followed by deoxalation to afford chiral 1,5-ketoesters in moderate to good yields.

An enantioselective synthesis of functionalized aza -flavanone derivatives using the N -heterocyclic carbene-catalyzed intramolecular Stetter reaction of sulphoamido benzaldehydes has been reported. This procedure presents the first original approach for synthesizing chiral functionalized flavonoids at the 3-position, containing an all-carbon quaternary stereogenic center. This advancement significantly enriches the chemical toolbox for the preparation of complex nitrogen-containing compounds and opens up new avenues for further research and development in synthetic organic chemistry., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

A highly enantioselective intramolecular NHC-catalyzed approach for the synthesis of fluoroalkylated benzopyranones and 3-coumaranones with all-carbon quaternary stereocenters is presented. This reaction is catalyzed by N -heterocyclic carbenes (NHCs) and involves annulation reactions between in situ generated acyl anion intermediates and highly substituted trifluoromethyl-β,β-disubstituted Michael acceptors. The method can also be extended to perfluoroalkyl homologues.

N -Heterocyclic carbenes (NHCs) catalyzing aza-Claisen rearrangement of α,β-unsaturated enals with cyclic vinylogous amides under oxidative conditions generating potentially biologically active dihydropyridinone-fused uracils have been developed. This strategy represents a unique NHC-activation-based path with the use of 6-aminouracils as stable α,β-diEWG cyclic vinylogous amides for the efficient synthesis of bicyclic N -unprotected lactams similar to those in many useful drugs.