Innovative catalytic protocols for the ring-closing Friedel-Crafts-type alkylation and alkenylation of arenes

Over the past years an astonishing number of highly chemo-and regioselective intramolecular Friedel-Crafts (lMFC)type alkylabons 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-clos- ing reactions even in the presence of polyfunctionalized cyclization precursors. Finally, the emerging field of catalytic enantios elective FC alkylations has recently concerned also intramolecular transformations both in the presence of chiral organic and organometallic promoters. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006.