摘要：SummaryOrtho-selective aromatic C-H functionalization is frequently used in organic synthesis and chemical/pharmaceutical industries. However, this reaction relies heavily on the use of directing groups suffering from limited substrate scope and extra steps to put on and remove the directing/protecting groups. Herein we present the previously neglected concept that enables good to nearly complete selectiveorthoposition. Proton transfer was utilized to tune the electron density on the aryl ring and determine the positional selectivity of electrophilic substitution. Consistently with deuteration experiments and DFT studies, this work demonstrates that acid-promoted proton transfer directs acceleratedortho-selective halogenation of NH/OH contained aromatic amines/phenols with excellent selectivity (>40 examples; up to 98:2ortho/paraselectivity). The application potential of this Fe-catalyzed method is demonstrated by the convenient synthesis of three alkaloids and tizanidine. This report raises the possibility that proton transfer could serve as the basis of developing new selective C-H functionalization reactions.Graphical AbstractDisplay OmittedHighlights•Highlyortho-selective halogenations of anilines and carbazoles•Lewis acids being able to accelerate EAS reactions•Proton shift found to be crucial for the regioselectivity•Practical iron sulfonate catalysis being scaled up to 100 gCatalysis; Organic Chemistry; Organic Synthesis
