Cycloalkylation of C(sp3)-H Bond with Neighboring Carboxylic Acid as Traceless Activating Group.

Selective functionalization of inert C(sp3)-H bond is one of cutting-edge challenges in chemical synthesis. A novel strategy for selective C(sp3)-H bond cycloalkylation is developed with neighboring carboxylic acid as a traceless activating group. Primary and secondary alkyl carboxylic acids undergo decarboxylation/α-C(sp3)-H cleavage/cycloalkylation to give the five-membered cyclization products, while tertiary acids undergo decarboxylation/β-C(sp3)-H cleavage/cycloalkylation to generate the six-membered cyclization products.