Photocatalytic [3 + 2]-annulation sodium tetraarylborate: a fundamental approach for synthesizing 1,4,2-diazaborole analogs.

Substantial advancements have been achieved in the field of photocatalytic borylation utilizing 4c-7e Lewis base-boryl radicals. However, the utilization of 3c-5e neutral boryl radicals for C-B bond formation remains relatively underexplored due to their inherent instability. In this study, we successfully demonstrated the direct construction of C-B bonds using sodium tetraarylborate as a key reagent.

Photocatalytic Borylation of Imines and Alkenes via Decarboxylation of Trimethylamine Carboxyborane: A New Approach for Generating Boryl Radicals.

In this study, we investigated the photocatalytic decarboxylation of trimethylamine carboxyborane under mild conditions, successfully generating boryl radicals for subsequent borylation reactions with imines and various alkenes. This method exhibited broad substrate compatibility, including the functionalization of biologically relevant molecules. Our findings expand the utility of trimethylamine carboxyborane beyond its role as a carbon-monoxide- and drug-releasing agent, highlighting its potential in radical chemistry through decarboxylation.

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 NiBr 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 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.