Rhodaelectro-catalyzed chemo-divergent C–H activations with alkylidenecyclopropanes for selective cyclopropylations

Abstract

Transition metal-catalyzed C–H activation has been recognized as a viable strategy in molecular sciences. In contrast, organometallic C–C activation remains relatively scarce. Herein, we report on the control of selectivity...

Recent Developments of Palladium- and Rhodium-Catalyzed β-Carbon Elimination Strategies

“…In 2021, the Ackermann group published a Rh(III)-catalyzed C-H activation reaction with ACPs and pyrimidyl-indoles as the substrate (Scheme 42). 63 Similar to the other reports discussed in this section, reaction with the pyrimidyl-indole and the ACP resulted in the dienylated products, though a variation of the methodology where the cyclopropane ring remained intact was also reported. Of note, the authors were able to isolate the cyclometalated rhodacycle resulting from the C-H activation and demonstrate its competency as a potential reaction intermediate (Scheme 42).…”

Recent Advances in Rhodium‐Catalyzed Electrochemical C−H Activation

“…Interestingly, when alkylidenecyclopropane switches from 14 to 16, the reaction afforded diversely substituted cyclopropanes 17 (Scheme 9). [78] The authors proposed a plausible catalytic cycle for the rhodaelectro-CÀ H-cyclopropylation (Figure 3). [78] Here, in situ generated active catalyst 3-I readily undergoes chelationassisted C2 selective CÀ H cyclometallation.…”

“…[78] The authors proposed a plausible catalytic cycle for the rhodaelectro-CÀ H-cyclopropylation (Figure 3). [78] Here, in situ generated active catalyst 3-I readily undergoes chelationassisted C2 selective CÀ H cyclometallation. Then, alkene migratory insertion followed by β-hydride elimination release the desired product 17 a and rhodium(I) species 3-IV.…”

Rh(iii)-Catalyzed dienylation and cyclopropylation of indoles at the C4 position with alkylidenecyclopropanes

“…15 Recently, Ackermann's group discovered that 1,3-dienes or cyclopropanes could be selectively introduced into the C-2 site of indoles with diverse ACPs via rhodaelectro catalysis (Scheme 1b). 16 However, poor stereoselectivity was observed for the 1,3-diene product.…”