Light-Promoted Nickel-Catalyzed C-O/C-N Coupling of Aryl Halides with Carboxylic Acids and Sulfonamides.

A general strategy for the construction of dual-functional carbon-heteroatom bonds has been developed via a light-promoted nickel catalytic system. Employing a simple NiBr2 as the catalyst without any exogeneous ligands and photosensitizers, a variety of esters and sulfonamide N-arylation derivatives, including celecoxib- and glimepiride-derived sulfonamides, were readily accessed with high functional group tolerance and high efficiency. Moreover, the UV-vis absorption spectrum and free radical trapping experiments aimed at revealing the mechanism of the reaction are also presented.

Photoredox/nickel dual catalyzed stereospecific synthesis of distal alkenyl ketones.

The selective C-C bond deconstruction/refunctionalization via a photoredox/nickel dual-catalyzed hydroalkylation of alkynes is developed under mild reaction conditions. In this protocol, a broad range of alkyl- and aryl-alkynes could react smoothly with cycloalkanols, affording the corresponding distal and site-specific vinyl-substituted ketones with high yields and excellent regioselectivities. Moreover, DFT calculations verified that the electron-rich behavior of aromatics and weak Brønsted bases have a common effect on the photocatalytic oxidant ring-opening of cyclobutanols.