A Highly Efficient Pd(PPh3)4-Catalyzed Suzuki Cross-Coupling Method for the Preparation of 2-Nitrobiphenyls from 1-Chloro-2-nitrobenzenes and Phenylboronic Acids

A simple and efficient method for Suzuki cross-coupling of highly substituted and congested 1-chloro-2-nitrobenzene with phenylboronic acid was developed, investigated, and optimized. The reaction conditions comprises a mixture of MeOH and water (4:1) as the reaction medium, readily available and cheap Pd(PPh3)(4) as catalyst, sodium carbonate as base, and microwave heating, which affords a fast reaction rate with good outcomes. The procedure was proven to have high functional group tolerance with phenylboronic acid and for 1-chloro-2-nitrobenzene and thus is a general method for the synthesis of 2-nitrobiphenyl. The target scaffold, 2-nitrobiphenyls, was produced in excellent yields with excellent selectivities in all cases.