Synthesis of Trifluoromethyl Pyrroles and Their Benzo Analogues

Approaches towards trifluoromethylpyrroles and their benzo analoguesare reviewed. 1 Introduction 2 Synthesis of Trifluoromethylpyrroles 2.1 Direct Trifluoromethylation 2.1.1 Radical Trifluoromethylation 2.1.2 Electrophilic Trifluoromethylation 2.1.3 Nucleophilic Trifluoromethylation 2.2 Synthesis by Cycloaddition Reactions 2.2.1 [3+2] Cycloaddition 2.2.2 [4+2] Cycloaddition and Cycloreversion 2.3 Synthesis Based on Carbonyl Compounds 2.4 Synthesis Based on α,β-Unsaturated Trifluoromethyl Ketones 2.5 Synthesis Based on Toluenesulfonylmethyl Isocyanide and Isocyanoacetate 2.6 Miscellaneous Approaches 3 Synthesis of Trifluoromethylindoles 3.1 Direct Trifluoromethylation 3.2 Formation of the C3-C4 Bond 3.3 Formation of the C2-C3 Bond 3.4 Formation of the C2-N Bond 4 Synthesis of Trifluoromethylindolizines 5 Conclusions