ChemInform Abstract: Synthesis of Multiply Arylated Heteroarenes, Including Bioactive Derivatives, via Palladium-Catalyzed Direct C-H Arylation of Heteroarenes with (Pseudo)Aryl Halides or Aryliodonium Salts

This review with 387 references covers the literature until the end of November 2013 on the synthesis of multiply arylated heteroarenes via highly selective palladium-catalyzed direct C–H arylation reactions of heteroarene derivatives with aryl halides or pseudohalides or aryliodonium salts. Particular attention has been made to describe the synthesis of biologically active compounds and substances that are privileged structural motifs in organic materials. The practicality, versatility, and limitations of the various developed arylation protocols are discussed. 1 Introduction 2 Synthesis of Multiply Arylated Five-Membered Hetero­arenes with One Heteroatom 2.1 Multiply Arylated Furan and Benzo[b]furan Derivatives 2.2 Multiply Arylated Thiophenes and Benzo[b]thiophene Derivatives 2.3 Multiply Arylated Pyrrole and Indole Derivatives 3 Synthesis of Multiply Arylated Five-Membered Hetero­arenes with Two or More Heteroatoms 3.1 Multiply Arylated Pyrazole and 2H-Indazole Derivatives 3.2 Multiply Arylated Isoxazole Derivatives 3.3 Multiply Arylated Oxazole Derivatives 3.4 Multiply Arylated Thiazole and Thiazole N-Oxide Derivatives 3.5 Multiply Arylated Imidazole and Imidazole N-Oxide Derivatives­ 3.6 Multiply Arylated 1,2,3-Triazole and 1,2,3-Triazole N-Oxide Derivatives 3.7 Diarylated 1,2,4-Triazole and 1,3,4-Thiadiazole Derivatives 3.8 Diarylated Sydnone, 2,1,3-Benzothiadiazole, and Tetrazole Derivatives 4 Synthesis of Multiply Arylated Six-Membered Hetero­arenes 4.1 Diarylated Pyridines, Pyridine N-Oxides, and Pyrazine N-Oxides 5 Synthesis of Multiply Arylated Compounds Formed by Five-Membered Heteroarenes Fused to Five-Membered Heteroarenes 5.1 Diarylated Thieno[2,3-b]thiophenes, Imidazo[1,2-b]pyrazoles, and Thiazolo[3,2-b]-1,2,4-triazoles 6 Synthesis of Multiply Arylated Compounds Formed by Six-Membered Heteroarenes Fused to Five-Membered Hetero­arenes 6.1 Diarylated Indolizines, Pyrimido[5,4-b]indolizines, Pyrrolo[2,3-b]pyridines, Pyrazolo[1,5-a]pyrimidines, Imidazo[1,2-a]pyridines, Imidazo[1,5-a]pyridines, Xanthines, Imidazo[1,2-b]tetrazines, Imidazo[1,2-a]pyrazines, and ­Furo[3,2-b]pyridines 7 Conclusions