One-pot borylation/arylation of 4-chloroquinolines and its application for the synthesis of various quinoline-based pharmacophores

Herein, we describe a new protocol for one-pot borylation/arylation of 4-chloroqunolines. The reaction proceeds through a palladium catalyzed one-pot two step process. In the first step borylation of differently substituted 4-chloroquinolines take place with bis(pinacolato)diboron (B₂pin₂) or bis(neopentylglycolato)diboron (B₂neo₂) with Pd(PPh₃)₂Cl₂ and KOAc and in the second step arylation with aryl halides in the presence of PPh₃, K₃PO₄ and H₂O furnish synthesis of C-4 arylated quinolines. This method gives access to various structurally interesting and pharmaceutically relevant C-4 arylated quinolines through C–C bond formation under simple and efficient condition. Additionally, it offers a new synthetic protocol for future functionalization of quinolines at C-4 position which has been encountered in various quinoline based drugs and biologically important scaffolds.