An N,N′‐dioxide/scandium(III) complex catalyzed, highly efficient conjugate addition of malonic esters to enynes is described. A range of trisubstituted 1,2‐allenyl ketones were obtained in high yields (up to 99 %) with good d.r. (up to 95/5) and excellent ee values (97 %–99 %). Moreover, the products could be easily transformed into chiral furan and 5‐hydroxypyrazoline derivatives, both of which are important skeletons of many biologically active compounds and pharmacologicals.

A highly efficient asymmetric ring-opening/cyclization/retro-Mannich reaction of cyclopropyl ketones with aryl 1,2-diamines has been realized using a chiral N,N'-dioxide/Sc(III) catalyst. Benzimidazoles containing chiral side chains were generated under mild reaction conditions in excellent outcomes (up to 99 % yield and 97 % ee). This method also provides efficient access to chiral benzimidazole-substituted amide and cycloheptene derivatives.

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In the present work, a novel series of trifluoromethyl-substituted tetrahydropyran derivatives were rationally designed and synthesized as potent DPP-4 inhibitors with significantly improved duration time of action over current commercially available DPP-4 inhibitors. The incorporation of the trifluoromethyl group on the 6-position of the tetrahydropyran ring of omarigliptin with the configuration of (2R,3S,5R,6S) not only significantly improves the overall pharmacokinetic profiles in mice but also maintains comparable DPP-4 inhibition activities. Further preclinical development of compound 2 exhibited its extraordinary efficacy in vivo and good safety profile. Clinical studies of compound 2 (Haisco HSK7653) are now ongoing in China, which revealed that inhibitor 2 could serve as an efficient candidate with a once-biweekly therapeutic regimen.

A highly enantioselective hydroxylative dearomatization of 2-naphthols with oxaziridines has been accomplished using an N,N′-dioxide–scandium(iii) complex catalyst. This methodology could be applied in the synthesis of bioactive lacinilenes in a gram-scale reaction.