Regioselective hydroarylation and arylation of maleimides with indazoles via a Rh(iii)-catalyzed C–H activation

Abstract

Switchable Rh(iii)-catalyzed highly regioselective hydroarylation and oxidative arylation of maleimides with 2-arylindazoles via C–H activation have been demonstrated.

Solvent-Switched Manganese(I)-Catalyzed Regiodivergent Distal vs Proximal C–H Alkylation of Imidazopyridine with Maleimide

“…As a consequence, a growing repertoire of C–H bond activation involving maleimides have been reported lately, including 1,4-conjugate addition, [1,1] spiro-annulation, [3 + 2], [4 + 2] cyclization, and Heck-type reactions with various substituted heteroaromatics . The reported metal-catalyzed alkylation of maleimides in various other scaffolds uses 4d and 5d transition metals in the presence of other metal co-oxidants, including expensive Ag salt . Thus, a sustainable regioselective ( ortho C–H vs C-3–H) alkylation in 2-arylimidazopyridine using 3d metal without silver and oxidant is highly appreciable.…”

Recent advances in rhodium-catalysed cross-dehydrogenative-coupling between two C(sp2)–H bonds

“…Later, Hajra and co-workers employed the same Rh complex for the alkenylation (Scheme 36b). 54 Interestingly, by employing a different oxidant, base and solvent, a totally different CDC reaction resulted with only one C–C single bond formation. In addition to maleimides, the oxidative regioselective alkenylation of 2-arylindazoles with methyl acrylate was also presented to provide the desired ortho -alkenylated product in moderate-to-good yields (Scheme 36c).…”

Maleimides in Directing‐Group‐Controlled Transition‐Metal‐Catalyzed Selective C−H Alkylation

“…Inspired by Fan and Zhang's work, Hajra subsequently developed the Rh(III)‐catalyzed switchable regioselective hydroarylation and oxidative arylation of maleimides with 2‐arylindazoles, affording various 3‐(2‐(2 H ‐indazol‐2‐yl) phenyl)succinimide and 3‐(2‐(2 H ‐indazol‐2‐yl)phenyl)maleimide derivatives in moderate to high yields (Scheme 17). [25b] These catalytic systems avoided intramolecular cyclization processes by taking AgSbF 6 as activator, AgOAc as oxidant instead of Cu(OAc) 2 , and 1,2‐DCE as solvent.…”