In the absence of ligand, Cs 2 CO 3 -promoted cross-coupling reaction of arenes with cyano-/nitro-substituted aryl halides in DMSO affording biaryls is reported. The cyano/nitro group in biaryls is useful and convenient for further transformation. The formation of dibenzofurans resulting from the reactions between arenes and 1-bromo-2-iodobenzene is also reported. On the basis of control experiments and theoretical studies, a radical mechanism is proposed for the formation of biaryls.

A transition-metal-free synthesis of quinazolin-4-ones by Cs 2 CO 3 -promoted S N Ar reaction of ortho -fluorobenzamides with amides followed by cyclization in dimethyl sulfoxide has been developed. The present procedure can provide efficient synthetic methods for the formation of both 2-substituted and 2,3-disubstituted quinazolin-4-one rings depending on the use of easily available starting materials and an efficient, one-pot protocol for the synthesis of the marketed drug product of methaqualone.

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KOH/DMSO-promoted C-N bond formation via nucleophilic aromatic substitution (SNAr) between chloroarenes or fluoroarenes with indoles and carbazole under transition metal-free conditions affording the corresponding N-arylated indoles and carbazoles has been developed.