Nickel-Catalyzed Decarbonylative Alkylation of Aroyl Fluorides Assisted by Lewis-Acidic Organoboranes

Herein, nickel-catalyzed decarbonylative C-F bond alkylation of aroyl fluorides with organoboron reagents is reported. Aroyl fluorides are more chemically stable than the corresponding aroyl chlorides and can be readily synthesized from the corresponding carboxylic acids. The fluoronickel intermediate formed via oxidative addition interacts with Lewis-acidic trialkylboranes, and the subsequent decarbonylative alkylation proceeds. This new synthetic methodology allows 1,2-bifunctionalization of aromatic carboxylic acids via palladium-catalyzed ortho-C-H arylation. In addition, an unprecedented 1,4-nickel migration on ortho-arylated aroyl fluorides was observed. As a demonstration of the synthetic utility of the present reaction, the sequential 1-alkyl-2-arylation of 3-hydroxy-2-naphthoic acid was accomplished via chemoselective alkylation at a fluorocarbonyl moiety and the subsequent C-O bond arylation at an acetoxy group.

P–C reductive elimination in Ru(ii) complexes to convert triarylphosphine ligands into five- or six-membered phosphacycles

η⁴-Phosphacycle complexes were obtained from PPh₂Ar (Ar = Ph, 1-Naph) via cyclometallation, alkyne insertion and P–C reductive elimination at a Ru centre.

Evidence for a zwitterionic transition state in double bond rotations within tungsten-vinyl complexes

The trianionic pincer supported tungsten-vinyl complex [CF3-ONO]W(O){(CH3)3CC[double bond, length as m-dash]C(CH3)2} (3syn) undergoes facile double bond rotation at ambient temperature. The degenerate methyl exchange rates were measured via selective inversion-recovery experiments. DFT computations in conjunction with experimentally determined rate constants support a double bond rotation that proceeds via a Zwiterionic transition state.