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Two unprecedented reactions using alkynyl 1,2-diketones and 1,3-dicarbonyls under phosphine catalysis have been achieved, furnishing a range of acyloxy allylidene malonates and γ-alkylidenebutenolides in good yields with high stereoselectivities.

We describe in this paper that using secondary OH as the kinetic resolution auxiliary group, a series of previously unavailable fluorinated fully-substituted carbon molecules can be obtained with excellent level of enantioselectivities.

Developing innovative dynamic kinetic resolution (DKR) modes and achieving the highly regio- and enantioselective semihydrogenation of unsymmetrical α-diketones are two formidable challenges in the field of contemporary asymmetric (transfer) hydrogenation. In this work, we report the highly regio- and stereoselective asymmetric semi-transfer hydrogenation of unsymmetrical α-diketones through a unique DKR mode, which features the reduction of the carbonyl group distal from the labile stereocenter, while the proximal carbonyl remains untouched. Moreover, the protocol affords a variety of enantioenriched acyclic ketones with α-hydroxy-α′-C(sp2)-functional groups, which represent a new product class that has not been furnished in known arts. The utilities of the products have been demonstrated in a series of further transformations including the rapid synthesis of drug molecules. Density functional theory calculations and plenty of control experiments have also been conducted to gain more mechanistic insights into the highly selective semihydrogenation. Nasl. z nasl. zaslona. Opis vira z dne 4. 1. 2023. Bibliografija: str. 596-598. Abstract. National Natural Science Foundation of China National Natural Science Foundation of China National Natural Science Foundation of China Research Program of the Chinese Academy of Sciences Fujian Natural Science Foundation ARRS ARRS

A unique deoxygenative cyclodimerization of alkynyl 1,2-diketones facilitated by Ti(O

An efficient carbene organocatalyzed route to enantioenriched chromenones, bearing one tri- or difluoromethylated stereogenic center in the β position of the carbonyl group, from o-allyloxybenzaldehydes is described. The one-pot transition-metal-free transformation exhibits a broad substrate scope and excellent enantioselectivity.