The nickel-catalyzed direct borylation and silylation of phenolic esters has been established. The key to this highly efficient acyl C−O bond borylative and silylative cleavage depends on the appropriate choice of different ligands and additives in the presence of nickel catalyst. Both transformations exhibit good functional group compatibility and can serve as powerful synthetic tools for late-stage functionalization of complex compounds. The elucidation of key mechanistic features of this newly developed acyl C−O bond activation in esters was confirmed by two well-characterized organonickel(II) intermediates.

A copper-catalyzed system has been introduced for the enantioselective defluoroalkylation of linear 1-(trifluoromethyl)alkenes through C-F activation to synthesize various gem-difluoroalkenes as carbonyl mimics. For the first time, arylboronate-activated alkyl Grignard reagents were uncovered in this cross-coupling reaction. Mechanistic studies confirmed that the tetraorganoborate complexes generated in situ were the key reactive species for this transformation.

By developing a mild Ni-catalyzed system, a method for direct borylation of sp(2) and sp(3) C-N bonds has been established. The key to this hightly efficient C-N bond borylative cleavage depends on the appropriate choice of the nickel catalyst Ni(COD)2, ICy·HCl as a ligand, and the use of 2-ethoxyethanol as the cosolvent. This transformation shows good functional group compatibility and can serve as a powerful synthetic tool for gram-scale synthesis and late-stage C-N borylation of complex compounds.

Amide and olefins are important synthetic intermediates with complementary reactivity which play a key role in the construction of natural products, pharmaceuticals and manmade materials. Converting the normally highly stable aliphatic amides into olefins directly is a challenging task. Here we show that a Ni/NHC-catalytic system has been established for decarbonylative elimination of aliphatic amides to generate various olefins via C–N and C–C bond cleavage. This study not only overcomes the acyl C–N bond activation in aliphatic amides, but also encompasses distinct chemical advances on a new type of elimination reaction called retro-hydroamidocarbonylation. This transformation shows good functional group compatibility and can serve as a powerful synthetic tool for late-stage olefination of amide groups in complex compounds.

Nickel-Catalyzed Borylation of Aryl-and Benzyltrimethylammonium Salts via C-N BondCleavage. -The catalytic system is capable of activating aryl and benzyl ammonium bonds for C-N borylation to produce a variety of organoborates. The key to the C-N bond cleavage depends on the appropriate choice of the nickel catalyst, the imidazole-based ligand, as well as the use of ethoxyethanol as the co-solvent. The transformation shows good functional group compatibility, is amenable to gram-scale synthesis and provides a tool for late-stage C-N borylation of complex compounds. -(HU, J.; SUN, H.; CAI, W.; PU, X.; ZHANG, Y.; SHI*, Z.; J. Org. Chem. 81 (2016) 1, 14-24, http://dx.