Ambient temperature ruthenium‐catalyzed C−H arylations were accomplished by visible light without additional photocatalysts. The robustness of the ruthenium‐catalyzed C−H functionalization protocol was reflected by a broad range of sensitive functional groups and synthetically useful pyrazoles, triazoles and sensitive nucleosides and nucleotides, as well as multifold C−H functionalizations. Biscyclometalated ruthenium complexes were identified as the key intermediates in the photoredox ruthenium catalysis by detailed computational and experimental mechanistic analysis. Calculations suggested that the in situ formed photoactive ruthenium species preferably underwent an inner‐sphere electron transfer.

Distal C(sp 2 )À H and C(sp 3 )À H functionalizations have recently emerged as step-economical tools for molecular synthesis. However, while the C(sp 2 )À C(sp 3 ) construction is of fundamental importance, its formation through double remote C(sp 2 )À H/C(sp 3 )À H activation has proven elusive. By merging the ruthenium-catalyzed meta-C(sp 2 )À H functionalization with an aliphatic hydrogen atom transfer (HAT) process, we, herein, describe the catalyzed twofold remote C(sp 2 )À H/C-(sp 3 )À H functionalizations via photo-induced ruthenium-mediated radical relay. Thus, meta-C(sp 2 )À H arene bonds and remote C(sp 3 )À H alkane bonds were activated by a single catalyst in a single operation. This process was accomplished at room temperature by visible light-notably without exogenous photocatalysts. Experimental and computational theory studies uncovered a manifold comprising ortho-CÀ H activation, single-electron-transfer (SET), 1,n-HAT (n = 5-7) and σactivation by means of a single ruthenium(II) catalyst.

Precise structural modifications of amino acids are of importance to tune biological properties or modify therapeutical capabilities relevant to drug discovery. Herein, we report a ruthenium-catalyzed meta-C–H deaminative alkylation with...

The ruthenium‐catalyzed synthesis of diarylmethane compounds was realized under exceedingly mild photoredox conditions without the use of exogenous photocatalysts. The versatility and robustness of the ruthenium‐catalyzed C−H benzylation was reflected by an ample scope, including multifold C−H functionalizations, as well as transformable pyrazoles, imidates and sensitive nucleosides. Mechanistic studies were indicative of a photoactive cyclometalated ruthenium complex, which also enabled versatile C−H allylations.