Low temperature dehydrations of non-activated alcohols via halide catalysis. Issue 6 (14th April 2016)

• Record Type: Journal Article
• Authors: Zhang, X.; Desrochers, S. J.; Carl, A. D.; Geagea, N.; Zielinski, K.; Emmert, M. H.
• Is Part Of: Organic chemistry frontiers. Volume 3:Issue 6(2016:Jun.)
• Page Start: 701
• Page End: 708
• Publication Date: 2016-04-14
• Subjects: Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1039/c6qo00069j
• Languages: English
• ISSNs: 2052-4110

Abstract

Abstract : Through concurrent halide and acid catalysis, olefin-forming dehydrations and non-rearranging Friedel–Crafts alkylations under mild conditions are established. Abstract : Activating kinetically inert C–O bonds such as in primary alcohols is an important challenge for the transformation of biomass-derived feedstocks. The herein described methodology addresses this issue through a combination of halide and acid catalysis. The novel mechanistic pathway proposed based on detailed experimental studies enables selective olefin formation from alcohols – as opposed to ether formation – at relatively low temperatures. Suitable substrates are tertiary, secondary, and even primary alcohols. Furthermore, the observed selectivity for the Hoffman elimination product and the realization of a non-rearranging Friedel–Crafts alkylation suggest that the reaction medium with high concentrations of halide (NBu4 Br) enables reaction outcomes that cannot be obtained through carbocation intermediates.