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Photocatalysis holds a pivotal position in modern organic synthesis, capable of inducing novel reactivities under mild and environmentally friendly reaction conditions. However, the merger of photocatalysis and transition‐metal‐catalyzed asymmetric C−H activation as an efficient and sustainable method for the construction of chiral molecules remains elusive and challenging. Herein, we develop a cobalt‐catalyzed enantioselective C−H activation reaction enabled by visible‐light photoredox catalysis, providing a synergistic catalytic strategy for the asymmetric dearomatization of indoles with high levels of enantioselectivity (96 % to >99 % ee). Mechanistic studies indicate that the excited photocatalyst was quenched by divalent cobalt species in the presence of Salox ligand, leading to the formation of catalytically active chiral Co(III) complex. Moreover, stoichiometric reactions of cobaltacycle intermediate with indole suggest that the irradiation of visible light also play a critical role in the dearomatization step. [ABSTRACT FROM AUTHOR]

Transition metal‐catalyzed enantioselective C−H carbonylation with carbon monoxide, an essential and easily available C1 feedstock, remains challenging. Here, we disclosed an unprecedented enantioselective C−H carbonylation catalyzed by inexpensive and readily available cobalt(II) salt. The reactions proceed efficiently through desymmetrization, kinetic resolution, and parallel kinetic resolution, affording a broad range of chiral isoindolinones in good yields with excellent enantioselectivities (up to 92 % yield and 99 % ee). The synthetic potential of this method was demonstrated by asymmetric synthesis of biological active compounds, such as (S)‐PD172938 and (S)‐Pazinaclone. The resulting chiral isoindolinones also serve as chiral ligands in cobalt‐catalyzed enantioselective C−H annulation with alkynes to construct phosphorus stereocenter. [ABSTRACT FROM AUTHOR]

Metalla‐electrocatalyzed C−H oxygenation represents one of the most straightforward and sustainable approaches to access valuable oxygenated molecules. Despite the significant advances, the development of enantioselective electrochemical C−H oxygenation reaction is very challenging and remains elusive. Herein, we described the first electrochemical CoII‐catalyzed enantioselective C−H alkoxylation. A broad range of enantioenriched alkoxylated phosphinamides were obtained in good yields with excellent enantioselectivities (up to 98 % yield and >99 % ee). An unusual cobalt(III) alcohol complex was prepared and fully characterized, which was proven to be a key intermediate of this C−H alkoxylation reaction. Mechanistic studies revealed that the oxidation of CoIII to CoIV was facilitated by a base and the whole process proceeded through a cobalt(III/IV/II) catalytic cycle. [ABSTRACT FROM AUTHOR]

In recent years, the merging of electrosynthesis with 3d metal catalyzed C−H activation has emerged as a sustainable and powerful technique in organic synthesis. Despite the impressive advantages, the development of an enantioselective version remains elusive and poses a daunting challenge. Herein, we report the first electrooxidative cobalt‐catalyzed enantio‐ and regioselective C−H/N−H annulation with olefins using an undivided cell at room temperature (up to 99 % ee). tBu‐Salox, a rationally designed Salox ligand bearing a bulky tert‐butyl group at the ortho‐position of phenol, was found to be crucial for this asymmetric annulation reaction. A strong cooperative effect between tBu‐Salox and 3,4,5‐trichloropyridine enabled the highly enantio‐ and regioselective C−H annulation with the more challenging α‐olefins without secondary bond interactions (up to 96 % ee and 97 : 3 rr). Cyclovoltametric studies, and the preparation, characterization, and transformation of cobaltacycle intermediates shed light on the mechanism of this reaction. [ABSTRACT FROM AUTHOR]

The past decade has witnessed a rapid progress in asymmetric C−H activation. However, the enantioselective C−H alkoxylation and amination with alcohols and free amines remains elusive. Herein, we disclose the first enantioselective dehydrogenative C−H alkoxylation and amination enabled by a simple cobalt/salicyloxazoline (Salox) catalysis. The use of cheap and readily available cobalt(II) salts as catalysts and Saloxs as chiral ligands provides an efficient method to access P‐stereogenic compounds in excellent enantioselectivities (up to >99 % ee). The practicality of this protocol is demonstrated by gram‐scale preparation and further derivatizations of the resulting P‐stereogenic phosphinamides, which offering a flexible asymmetric alternative to access P‐stereogenic mono‐ and diphosphine chiral ligands. Preliminary mechanistic studies on the enantioselective C−H alkoxylation reaction suggest that a cobalt(III/IV/II) catalytic cycle might be involved. [ABSTRACT FROM AUTHOR]

Previous methods on CoIII‐catalyzed asymmetric C−H activation rely on the use of tailor‐made cyclopentadienyl‐ligated CoIII complexes, which require lengthy steps for the preparation. Herein, we report an unprecedented enantioselective C−H functionalization enabled by a simple cobalt/salicyloxazoline (Salox) catalysis. The chiral Salox ligands can be easily prepared in one step from salicylonitrile and chiral amino alcohols. A broad range of P‐stereogenic compounds were synthesized in high yields with excellent enantioselectivities (45 examples, up to 99 % yield and >99 % ee). The isolation and characterization of several intermediates provided insights into the generation of active catalytic cobalt species, the action of Salox, and the mode of stereocontrol. [ABSTRACT FROM AUTHOR]