Innovative Catalytic Protocols for the Ring‐Closing Friedel–Crafts‐Type Alkylation and Alkenylation of Arenes

Abstract

Abstract Over the past years an astonishing number of highly chemo‐ and regioselective intramolecular Friedel–Crafts (IMFC)‐type alkylations of aromatic compounds have been described in the literature that allow remarkable synthetic shortcuts for the preparation of challenging aromatic compounds. In particular, both transition metal and conventional and unusual Lewis acids (LAs) have been described to promote ring‐closing reactions even in the presence of polyfunctionalized cyclization precursors. Finally, the emerging field of catalytic enantioselective FC alkylations has recently concerned also intramolecular transformations both in the presence of chiral organic and organometallic promoters. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)