A novel ruthenium catalyst is introduced which contains solely achiral ligands and acquires its chirality entirely from octahedral centrochirality. The configurationally stable catalyst is demonstrated to catalyze the alkynylation of trifluoromethyl ketones with very high enantioselectivity (up to >99% ee) at low catalyst loadings (down to 0.2 mol%).

A new class of chiral ruthenium catalysts is introduced in which ruthenium is cyclometalated by two 7methyl-1,7-phenanthrolinium heterocycles, resulting in chelating pyridylidene remote N-heterocyclic carbene ligands (rNHCs). The overall chirality results from a stereogenic metal center featuring either a Λ or Δ absolute configuration. This work features the importance of the relative metal-centered stereochemistry. Only the non-C 2 -symmetric chiral-at-ruthenium complexes display unprecedented catalytic activity for the intramolecular C(sp 3 )−H amidation of 1,4,2-dioxazol-5-ones to provide chiral γ-lactams with up to 99:1 er and catalyst loadings down to 0.005 mol % (up to 11 200 TON), while the C 2 -symmetric diastereomer favors an undesired Curtiustype rearrangement. DFT calculations elucidate the origins of the superior C−H amidation reactivity displayed by the non-C 2 -symmetric catalysts compared to related C 2 -symmetric counterparts.

This study demonstrates for the first time that easily accessible transition-metal acylnitrenoids can be used for controlled direct C(sp 3)-H oxygenations. Specifically, a ruthenium catalyst activates N-benzoyloxycarbamates as nitrene precursors towards regioselective intramolecular C À H oxygenations to provide cyclic carbonates, hydroxylated carbamates, or 1,2-diols. The method can be applied to the chemoselective CÀH oxygenation of benzylic, allylic, and propargylic C(sp 3)ÀH bonds. The reaction can be performed in an enantioselective fashion and switched in a catalyst-controlled fashion between C À H oxygenation and C À H amination. This work provides a new reaction mode for the regiocontrolled and stereocontrolled conversion of C(sp 3)-H into C(sp 3) À O bonds.

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A sustainable C-C bond formation is merged with the catalytic asymmetric generation of one or two stereocenters. The introduced catalytic asymmetric cross-coupling of two C(sp3)-H groups with molecular oxygen as the oxidant profits from the oxidative robustness of a chiral-at-metal rhodium(III) catalyst and exploits an autoxidation mechanism or visible-light photosensitized oxidation. In the latter case, the catalyst serves a dual function, namely as a chiral Lewis acid for catalyzing enantioselective enolate chemistry and at the same time as a visible-light-driven photoredox catalyst.