Electrochemically enabled rhodium-catalyzed [4 + 2] annulations of arenes with alkynes

Abstract

Herein, the electrochemically driven, Rh(III)-catalyzed regioselective annulations of arenes with alkynes have been established. The strategy combined by rhodium catalyst with electricity not only avoids the need for stoichiometric amount...

Electrochemical Syntheses of Polycyclic Aromatic Hydrocarbons (PAHs)

“…In this context, the rhodium‐catalyzed electrochemical regioselective annulations of 6‐phenylpurines and 6‐phenyl‐7‐deazapurines with alkynes was developed by the Zhang and Ling groups, independently ( Figure ). [ 147,148 ] As in the previous Ackermann studies, electricity was elegantly employed to regenerate the active rhodium‐based catalyst, promoting the evolution of H 2 to overall also reducing the reaction temperature. This electrochemical approach featured a broad substrate scope, affording a series of polycyclic purinium and 7‐deazapurinium salts in high yields.…”

An electrochemical method for direct sulfonylation of BODIPYs under green conditions

“…6 Among them, electrochemical oxidation and sulfonation reactions have been able to construct various sulfonated aromatic hydrocarbons well. 7 Based on our continuous interest in developing electrochemical transformations, 8 we speculated that it may be feasible to functionalize BODIPYs under mild electrochemical conditions based on radical–radical cross-coupling reactions, although such reactions have been rarely explored. Moreover, the green protocol including the utility of a cheap NaCl electrolyte and aqueous solution provided a practical alternative to traditional methods (Scheme 1b).…”

Electrochemical oxidative intramolecular annulation of aryl phosphine compounds: an efficient approach for synthesizing π-conjugated phosphonium salts

“…As an efficient, mild, eco-friendly method, organic electrochemical synthesis offers a directed oxidative route for organic substrates under oxidant-free conditions and has received continuous attention. Organic electrochemical synthesis has been utilized to achieve the C-H activation/annulation, [22][23][24][25] the construction of polycyclic aza-fused arenes [26][27][28][29] and polycyclic S-containing arenes, 30 and the electrochemical transformation of phosphorus compounds have also been reported. [31][32][33] With our continuous interests in electrochemistry [34][35][36][37][38][39] and multiple C-H activations and annulation 19,40 , herein, we report a versatile electrochemical oxidative method under oxidant-free conditions to produce fused polycyclic phosphonium salts via the C-H activation/annulation of aryl phosphine compounds (Scheme 1d), and metals and oxidants could be readily avoided in this strategy.…”