Rhodium(iii)-catalyzed regioselective distal ortho C–H alkenylation of N-benzyl/furanylmethylpyrazoles directed by N-coordinating heterocycles

Abstract

C–H activation of challenging N-benzylpyrazoles was accomplished by employing rhodium(III) catalysis. This C–H activation reaction proceeds via a six-membered rhodacycle intermediate and enables distal regioselective alkenyl-functionalization on the aromatic ring of N-benzylpyrazoles without the formation of bis-adducts. High functional group tolerance, low catalyst loading, and superior reactivity of olefin moieties towards N-benzylpyrazoles are some of the attractive features of this protocol. This protocol offers a broad scope for the regioselective functionalization of indazoles, benzo[d][1,2,3]triazoles, and 1-(furan-3-ylmethyl)-1H-pyrazole in good yields.