Transition‐Metal‐Catalyzed Benzylation of Arenes and Heteroarenes

Abstract

Friedel–Crafts‐type benzylation of various aromatic and heteroaromatic compounds with benzylic acetates, alcohols, and carbonates was promoted under mild reaction conditions by a series of Rh, Ir, Pd, and Pt catalysts (see scheme; R1=H, Me; R2=H, Cl, MeO; R3=H, Ac, CO2Me). The desired products were obtained in high yields and with high selectivities.

Gold‐Catalysed Direct Couplings of Indoles and Pyrroles with 1,3‐Dicarbonyl Compounds

“…[17] Therefore, the development of new direct C À C coupling reactions of arenes/heteroarenes is an important topic in organometallic chemistry and catalysis. [18] In our search for new and improved catalysts for the regioselective electrophilic substitution of indoles and pyrroles we studied their gold-catalysed alkenylation with 1,3-dicarbonyl compounds (Scheme 1). Gold is a soft transition metal showing high electrophilic affinity for alkynes, arenes, and allenes.…”

Neues Zentrum für Angewandte Katalyseforschung: Institute aus Berlin und Rostock fusionieren zum Leibniz‐Institut für Katalyse e. V. an der Universität Rostock

“…Deshalb werden derzeit auch Friedel-Crafts-artige Alkylierungen von elektronenreichen, aber auch elektronenarmen Aromaten und Heteroaromaten unter Verwendung katalytischer Mengen einfacher Übergangsmetallsalze (Pt, Au, aber auch Fe und anderer Nicht-Edelmetalle) bearbeitet [9,10].…”

A Simple Catalyst for the Efficient Benzylation of Arenes by Using Alcohols, Ethers, Styrenes, Aldehydes, or Ketones

“…[1] These conditions, however, afford the concomitant production of hydrogen halides that often induce side reactions and many byproducts. As an alternative, recent reports have proposed the use of alcohols, [2][3][4] ethers, [5,6] styrenes [7,8] or benzylic acetates [9] for which milder reaction conditions are needed and side reactions are avoided.…”