Late-stage diversification by rutheniumelectro-catalyzed C–H mono- and di-acyloxylation

Recent Applications of Homogeneous Catalysis in Electrochemical Organic Synthesis

“…52 In 2020, Zhong and co-workers achieved rutheniumelectro-catalyzed mono-and diacyloxylation of aryl C-H bonds (Figure 6g). 53 That same year, the Ackermann group reported alkyne annulation reactions that involve alkenylic C-H and N-H bonds and proceed via a key azaruthena(II)-bicyclo[3.2.0]heptadiene intermediate (Figure 6h). 54 These investigators proposed a Ru 2+ /Ru 3+ /Ru + pathway in which anodic oxidation not only regenerates the catalyst but also induces reductive elimination.…”

Synthesis of P-stereogenic cyclicphosphinic amidesviaelectrochemically enabled cobalt-catalyzed enantioselective C–H annulation

“…In alignment with our continued interest in the pursuit of new chiral phosphorous ligands and catalysts for asymmetrical transformations, 17 Co-catalyzed C–H activations 18 and electrochemical C–H functionalizations, 19 we envisioned that the in situ generated chiral Co III from Co II salt with a Salox ligand via anode oxidation might enable enantioselective C–H activation, thus giving a great chance for accessing P-stereogenic compounds (Scheme 1c). The main challenges in this cobalt catalyzed asymmetric electrocatalysis include (1) lower reactivities of cobalt catalysts as well as their easy deactivation by a cathodic reduction in an undivided cell; (2) the unsuspected stability of Salox ligands in electrochemical conditions; and (3) infaust coactions of the electrolyte, which may destroy the enantio-determining transition state.…”

Rh(iii)-catalyzed [4 + 1] cyclization of aryl substituted pyrazoles with cyclopropanols via C–H activation

“…11 However, further development of efficient strategies in Rh( iii )-catalyzed tandem cyclization reactions with cyclopropanols through sequential functionalization of C–H and N–H bonds is still significant for synthetic chemistry. Inspired by these achievements and as a continuation of our interest in transition-metal-catalyzed C–H activation, 12 herein we wish to report an efficient rhodium-catalyzed formal [4 + 1]-cyclization reaction of aryl substituted pyrazoles with cyclopropanols through C–H bond activation/cyclization processes to selectively construct a series of carbonyl functionalized pyrazolo[5,1- a ]isoindoles (Scheme 1d).…”