Mn-Catalyzed Electrooxidative Undirected C–H/P–H Cross-Coupling between Aromatics and Diphenyl Phosphine Oxides

Abstract

C–P bonds are widely found in a great many bioactive compounds and functional molecules. Transition-metal-catalyzed dehydrogenative C–H/P–H cross-coupling plays a crucial part in C–P bond formation since it requires no pretreatment of substrates. Herein, we reported a Mn-catalyzed electrochemical intermolecular dehydrogenative cross-coupling between aryl C–H and diphenyl phosphine oxides. In undivided cells, a series of phosphorylation or diphosphorylation products could be obtained separately by adjusting the proportion of substrates. A catalytic amount of inexpensive Mn­(II) salt was used, and no external chemical oxidants were needed in this process. A kinetic isotope effect experiment suggested that the C–H activation was not the rate-determining step.

Electrochemical C–H phosphorylation of arenes in continuous flow suitable for late-stage functionalization

“…Trialkyl phosphites bearing primary alkyl chains of different lengths reacted smoothly to give the corresponding phosphonate products (31)(32)(33)(34)(35)(36). The electrochemical method was also suitable for late-stage functionalization of relatively complex natural products and bioactive compounds (37)(38)(39)(40)(41)(42)(43)(44)(45)(46). Compounds that contained multiple aryl rings reacted at the most electron-rich one (38, 40, 41, and 46).…”

“…Organic electrochemistry has been shown to be an enabling technology in addressing the challenges in sustainable synthesis [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] . In this context, electrochemical C-H phosphorylation of electron-rich heteroaromatics 38,39 and arenes bearing directing groups 40,41 have been reported. Reactions of electrondeficient arenes require metal catalysts and impractical threeelectrode configuration in divided cells [42][43][44][45][46][47] .…”

Electrochemically driven regioselective C−H phosphorylation of group 8 metallocenes

“…Although compound 2a exhibited no apparent peak from 0 to 1.6 V (Supplementary Fig. 1 , curve V, Supporting Information) 50 , 63 , 69 , 2a showed an oxidative potential at 1.25 V in the presence of the base NaOMe (Supplementary Fig. 1 , curve VI, Supporting Information).…”

Copper-Catalyzed Phosphorylation of 2,3-Allenoic Acids and Phosphine Oxide: Access to Phosphorylated Butenolides

“…Phosphorus-containing heterocycles are an important class of organophosphorus compounds, applied widely in synthetic and medicinal chemistry, as well as material science and universal ligands, drawing considerable attention for both industrial and medicinal applications. Generally, the traditional synthesis of phosphorus-substituted heterocycles is based on direct phosphorylation of the parent heterocycles . Various effective C–P bond reactions involving the addition of P-centered radicals to initiate the formation of the heterocycle have recently been developed .…”