Electrophilic Functionalization of Non-Activated Olefins Catalyzed by Lewis Superacids

Abstract

The use of metallic triflates and triflimidates as efficient catalysts in recent cycloisomerizations, hydroalkoxylations, hydrocarboxylations, hydrothiolations, Friedel-Crafts reactions, a-amidoalkylation and other C-C, C-O and C-S coupling reactions is reviewed.

Bis(μ-oxo)–Dititanium(IV)–Chiral Binaphthyldisulfonate Complexes for Highly Enantioselective Intramolecular Hydroalkoxylation of Nonactivated Alkenes

“…The asymmetric hydroalkoxylation of alkenes is an attractive method to construct chiral ethers, as it is simple and intrinsically atom-economical . Strong Lewis and Brønsted acids enable a very efficient hydroalkoxylation of alkenes, − but an enantioselective hydroalkoxylation catalyzed by chiral Lewis acids has suffered from harsh reaction conditions and hampered enantioselectivity in comparison to that by chiral Brønsted acids (Scheme a–d). − An intriguing question would be whether the activity of strong Lewis acids and a high selectivity of chiral ligands can be combined in a single catalyst. The prevalence of triflate Lewis acids suggests that chiral binaphthyldisulfonic acids would be suitable candidates that preserve the Lewis acidity of the central metals.…”