Electrolytic C–H Oxygenation via Oxidatively Induced Reductive Elimination in Rh Catalysis

Abstract

Herein, we describe the development of a Rh-catalyzed C−H acyloxylation under mild electrolytic conditions. Anodic oxidation of a key rhodacyclic carboxylate intermediate was found to enable the product-releasing C−O bond-forming reductive elimination process. An accumulation of carboxylate near the electrode surface was rationalized to further induce the desired C−O bond formation, allowing an ambient catalytic C−H oxygenation using stoichiometric amounts of readily accessible carboxylic acid coupling partners.

Oxidatively induced reactivity in Rh(iii)-catalyzed 7-azaindole synthesis: insights into the role of the silver additive

“…Considering that there were two types of Ag(I) additives employed in the 7-azaindole synthesis (Scheme 1b), it is easy to rationalize how the [Cp*RhCl 2 ] 2 precatalysts could transform into its active form 1. As the dehalogenation of [Cp*RhCl 2 ] 2 by the soluble Ag(I) additive has been demonstrated in related Rhcatalysis, 18,19 we presume an identical fate of the pre-catalyst given the similarities in the experimental conditions. Thus, the reaction between [Cp*RhCl 2 ] 2 and four equivalents of AgSbF 6 additive will form AgCl that will eventually precipitate out of the solution, leaving two equivalents of dicationic Cp*Rh(III) complex and four equivalents of [SbF 6 ]counter anions.…”

Selective oxidation of C (sp3)—H bonds enabled by ruthenium clusters containing pyridine‐alkoxide ligands

“…The present conditions worked well for the ethylbenzenes with electrondonating or electron-withdrawing substitutes at different positions (Entries 5-11). Those with an electron-donating group such as methoxy and methyl (Entries 6-8) gave 2) 48.28 (10), O(1) Ru( 2) Ru (1) 48.28 (10), N(1) Ru( 2) Ru(3) 166.33 (15), N(1) Ru( 2) Ru (1) 106.17 (15). higher yields than those with an electron-withdrawing group such as bromo and chloro (Entries 7-11).…”

“…The organic layer was separated, washed with brine and dried over anhydrous MgSO 4 for several hours. After removal 3) Ru( 2) 60.360 (19), Ru( 1) O( 1) Ru (2) 83.76 (15), O(1) Ru( 1) Ru( 2) 48.48 (12), O(1) Ru( 2) Ru (1) 47.76 (11), N(1) Ru( 1) Ru(3) 163.98 (15), N(1) Ru( 1) Ru (2) 103.67 (14). 3) Ru( 2) 60.416 (13), Ru( 1) O( 10) Ru (2) 84.41 (10), O( 10) Ru( 1) Ru( 2) 48.11 (7), O( 10) Ru( 2) Ru (1) 47.48 (7), N(1) Ru( 1) Ru(3) 163.34 (9), N(1) Ru( 1…”

“…[1][2][3][4][5][6][7][8][9] As C H bonds are ubiquitous in organic molecules, transforming them directly to desired functional groups is a valuable synthetic strategy. [10][11][12][13][14][15][16][17] Transition metal complexes that can mediate the transformations of sp 3 C H bonds via hydrogen atom abstraction, C H insertion, and C H oxidation or via the formation of organometallic intermediates provide the basis of this research field. [10,[18][19][20] C H functionalization remains a highly significant research field, as evidenced by the constant output of new strategies to improve the selectivity and efficiency and widen the substrate scope.…”

Electrochemical ruthenium-catalysed C–H activation in water through heterogenization of a molecular catalyst

“…1–9 As C–H bonds are ubiquitous in organic molecules, transforming them directly into desired functional groups is a highly efficient and valuable synthetic strategy. 10–17 Transition metal complexes that can mediate transformations of sp 2 and sp 3 carbon–hydrogen bonds via hydrogen atom abstraction, C–H insertions and C–H oxidations or via the formation of organometallic intermediates provide the basis of this research field. 10,18–20 C–H functionalisation remains a highly significant research field as evidenced by the constant output of new strategies to improve selectivity and efficiency and to increase the substrate scope.…”