ChemInform Abstract: INSERTION OF CARBON DIOXIDE INTO THE RHODIUM‐CARBON BOND, THE STRUCTURE OF TRIS(TRIPHENYLPHOSPHINE)RHODIUM BENZOATE

Rhodium(I)-Catalyzed Aryl C–H Carboxylation of 2-Arylanilines with CO2

“…Simultaneously, the Yu group also reported efficient methods of Pd-catalyzed aryl C–H carboxylation of benzylic alcohols and benzamides . However, direct carboxylation of aryl C–H bonds of amine derivatives via catalytic fixation of CO 2 with a transition-metal catalyst has not yet been resolved. , Moreover, although Rh­(I) catalysts have been extensively utilized in C–H activation reactions, ,,,, their use in catalytic C–H carboxylation using CO 2 is very scarce, even though the insertion of CO 2 into the rhodium–carbon bond of a rhodium complex had been studied more than four decades ago …”

“…Based on Iwasawa’s pioneering studies and our recent work on Rh­(II)-catalyzed C–H carboxylation of 2-arylphenols with CO 2 , , we envisioned that Rh-catalyzed C–H carboxylation of 2-arylanilines might proceed with a broader substrate scope in a general manner. Another important aspect of the Rh-catalyzed process is that it may constitute a fundamental step in the fixation of CO 2 , which involves the insertion of CO 2 into a carbon–metal bond and may provide more hints for mechanistic studies of related transition-metal-catalyzed C–C bond formation reactions using CO 2 . Herein, we report a ligand-promoted, Rh­(I)-catalyzed direct C–H carboxylation of 2-(hetero)­arylanilines under redox-neutral conditions and atmospheric pressure of CO 2 , which was assisted by the chelation of the amino group, leading to the production of phenanthridinones (Scheme d)…”

Rhodium(I)-Catalysed Aryl C–H Carboxylation of 2-Arylanilines with CO2

“…1b). [60][61][62][63][64] Phenanthridinone is an important moiety found in natural products and biologically active molecules. 65 Consequently, several methods have been developed for the synthesis of phenanthridinone derivatives.…”

“…Another important aspect of the Rh-catalysed process is that it may constitute a fundamental step in the fixation of CO2, which involves the insertion of CO2 into a carbon-metal bond and may provide more hints for mechanistic studies of related transition metal-catalysed C-C bond formation reactions using CO2. [62][63][64] Herein, we report a phosphine ligand-promoted, Rh(I)-catalysed C-H carboxylation of 2-(hetero)arylanilines under atmospheric pressure of CO2 and redox-neutral conditions, which was assisted by the chelation of the amino group, leading to the production of phenanthridinones (Fig. 1).…”