Palladium-Catalyzed Cross-Coupling of gem-Difluorocyclopropanes with gem-Diborylalkanes for the Synthesis of Boryl-Substituted Fluorinated Alkenes.

This study presents a novel method for the regioselective coupling of gem-difluorinated cyclopropanes with gem-diborylmethane, utilizing a Pd-catalyst system. This innovative approach enables the synthesis of 2-fluoroalkenyl monoboronate scaffolds with high Z-selectivity. The resulting products undergo further transformations, including oxidation, Suzuki cross-coupling, and trifluoroborylation, all of which are achieved with good yields. This work introduces a valuable synthetic pathway to access important fluorinated compounds for various applications in organic chemistry.

Three-component reaction of gem-difluorinated cyclopropanes with alkenes and B2pin2 for the synthesis of monofluoroalkenes.

Borylative difunctionalization of alkenes has emerged as a powerful approach for synthesizing highly functionalized molecules. Herein, dual Cu/Pd-catalysed borylfluoroallylation of alkenes was smoothly achieved by using gem-difluorinated cyclopropanes and B2pin2, providing the corresponding monofluoroalkene scaffolds in moderate to high yields with excellent stereoselectivity. Moreover, an array of synthetic building blocks can be obtained by downstream transformations.

Cu/Pd-Catalyzed cis-Borylfluoroallylation of Alkynes for the Synthesis of Boryl-Substituted Monofluoroalkenes.

Monofluoroalkenes normally act as metabolically stable bioisosteres for amide groups (-NH-CO-) and have widespread applications in drug discovery. Additionally, they are widely used as building blocks in organic synthesis. In this study, the Cu/Pd-catalyzed cis-borylfluoroallylation of alkynes was achieved, providing a modular and general tactic for the preparation of monofluorinated alkene scaffolds with high regioselectivity and stereoselectivity. Moreover, an array of synthetic building blocks can be generated by downstream transformations.

Asymmetric Construction of α-Substituted ß-Hydroxy Lactones via Ni Catalyzed Decarboxylative Addition Reaction.

We described a Ni-bidentate oxazoline catalyzed highly enantio- and diastereoselective decarboxylative aldol reaction of 2-oxotetrahydrofuran-3-carboxylic acid/2-oxochromane-3-carboxylic acid derivatives with different kinds of carbonyls. Under optimal reaction conditions, α-substituted ß-hydroxy butyrolactones and dihydrocoumarins with an all-carbon quaternary stereocenter have been generated with high levels of functional-group compatibility. Furthermore, proficient transformations of products were also described, in which an aliphatic tertiary alcohol and a multi-substituted 1,4-diol were smoothly constructed through hydrogenation and ring-opening reaction, respectively.

Access to Divergent Fluorinated Enynes and Arenes via Palladium-Catalyzed Ring-Opening Alkynylation of gem-Difluorinated Cyclopropanes.

Herein, we describe a palladium-catalyzed alkynylation of gem-difluorinated cyclopropanes via C-C bond activation/C-F bond cleavage, followed by C-C(sp) coupling. The new approach proceeds with broad substrate scope under mild reaction conditions, whereas both 1,1-disubstituted and complex-molecule-modified gem-difluorinated cyclopropanes react smoothly with high stereoselectivity. The developed method provides efficient and convenient ways access to diversity of important fluorinated enynes and arenes by slightly modification of the reaction conditions.

Palladium-Catalyzed Stereoselective Defluorination Arylation/Alkenylation/Alkylation of gem-Difluorinated Cyclopropanes.

A palladium-catalyzed cross-coupling of gem-difluorinated cyclopropanes with boronic acids, providing the corresponding arylated/alkenylated/alkylated 2-fluoroallylic scaffolds, is generated. This new approach has good functional group compatibility for both gem-difluorinated cyclopropanes and boronic acids; thus, an array of synthetic building blocks of monofluoroalkene scaffolds including conjugated fluorodiene and skipped fluorodiene gave good yields with high Z-selectivity. Moreover, proficient application was described for monofluoroalkene, whereas the corresponding alkyl fluoride was constructed through hydrogenation.

Copper-catalyzed/mediated borylation reactions of epoxides with diboron reagents: access to ß-hydroxyl boronic esters.

We report the first copper-catalyzed/mediated borylative ring opening reaction of epoxides. This process represents a direct borylative C(sp3)-O bond cleavage of terminal epoxide substrates with commercially available diboron reagents. A wide range of epoxides with different functional groups are involved, and were subsequently converted to the corresponding ß-hydroxyl boronic esters smoothly. Moreover, the ring opening product ß-pinacol boronate alcohol provided a more beneficial approach for the formation of C-C and C-N bonds.