A cobalt-catalyzed decarboxylative Negishi coupling reaction of redox-active aliphatic esters with organozinc reagents was developed. The method enabled efficient alkyl-aryl, alkyl-alkenyl, and alkyl-alkynyl coupling reactions under mild reaction conditions with no external ligand or additive needed. The success of an in situ activation protocol and the facile synthesis of the drug molecule (±)-preclamol highlight the synthetic potential of this method. Mechanistic studies indicated that a radical mechanism is involved.

The copper-catalyzed stereoselective defluorinative borylation and silylation of gem-difluoroalkenes was developed. The protocol led to the exclusive formation of Z type monofluoroalkenyl borons and silanes in generally good efficiency with broad substrate scope. The products formed could be readily transformed to other Fcontaining molecules by taking advantage of the versatile reactivities of CÀB and CÀSi bonds. Experimental and theoretical mechanistic studies were conducted which support an olefin insertion/ syn-planar b-F elimination pathway.

A redox-neutral bimetallic Rh(iii)/Ag(i) relay catalysis allowed the efficient construction of 3-alkylidene isoindolinones and 3-alkylidene isobenzofuranones. The Rh(iii) catalyst was responsible for the C-H monofluoroalkenylation reaction, whereas the Ag(i) salt was an activator for the follow-up cyclization. The methodology developed was applied as a key step in the rapid total synthesis of the natural product aristolactam BII.

A reductive cross-coupling of gem-difluoroalkenes with diverse unactivated and heteroatom substituted olefins through a Fe-catalyzed hydrogen atom transfer (HAT) strategy is reported. Different from the previous HAT-type olefin cross-coupling reactions, the presence of a fluorine atom in the molecule results in a stereoselective β-F cleavage, leading to a C(sp)-C(sp) bond formation. A wide variety of alkylated monofluoroalkenes were obtained in good efficiency with excellent Z selectivity under air- and water-tolerant reaction conditions. A similar defluorinative coupling reaction of monofluoroalkenes was also realized.

A novel synthesis of α-CF3 and α-CF2H amines via the aminofluorination of gem-difluoroalkenes and mono-fluoroalkenes, respectively, is reported. The method employs Selectfluor as an electrophilic fluorine source and acetonitrile as a nitrogen source. Mechanistic studies revealed a single-electron oxidation/fluorine-abstraction/Ritter-type amination pathway. The protocol allowed the synthesis of a broad range of fluorinated amines including those bearing quaternary carbon centers with good efficiency and functional group tolerance.