An unprecedented C2-alkylation of quinoline N-oxide derivatives via CÀC bond activation of tert-and sec-alkyl alcohol is described using hypervalent iodine (III) reagent PhI(OAc) 2 (PIDA). This regioselective alkylation using mild hypervalent iodine reagents is more practical, operationally simple and transition metal free. The reaction proceeds efficiently with a broad range of substrates including quinoline, isoquinoline, and pyridine N-oxides using a variety of tert-/secalcohols. From experimental outcome, we also propose a rationalized mechanism, mediated by PIDA.

A room-temperature C–H bond functionalization of benzamides has been developed by merging a photocatalyst with a cobalt catalyst for the synthesis of isoindolone spirosuccinimides. The reaction proceeds in aerobic conditions and does not require any sacrificial external oxidants such as Ag­(I) or Mn­(III) salts. Visible light activates the photocatalyst, and it acts as an electron-transfer reagent and helps in the fundamental organometallic steps by modulating the oxidation state of the cobalt complex. This C–H bond functionalization and spirocyclization showed wide substrate scope and good functional group tolerance. A possible reaction mechanism was proposed from the experimental outcome, showing that C–H bond activation is irreversible and not the rate-determining step.

An efficient photocatalytic method was developed for the remote C5-H bond carboxylation of 8-aminoquinoline amide and sulfonamide derivatives. This methodology uses in situ generated •CBr3 radical as a carboxylation agent with alcohol and is further extended to a variety of arenes and heteroarenes to synthesize the desired carboxylated product in moderate-to-good yields. The reaction proceeding through a single electron transfer pathway was established by a control experiment, and a butylated hydroxytoluene-trapped aryl radical cation intermediate in high-resolution mass spectrometry was identified.

A simple and practical heterogeneous Cu‐MnO catalyzed regioselective halogenation of anilides and quinolines under irradiation with household 40 W incandescent lamp was developed. This method uses a recyclable Cu‐MnO catalyst, acetonitrile as an industrially friendly solvent, and economic N‐halo succinimides as a halogenating source. The reaction is scalable and well tolerated with a broad range of functional groups.