title: Hydrogenation of
abstract: The course of the hydrogenation of [5]- and [6]metacyclophane (1b and 1c) and their thermochemistry is described. Both compounds are hydrogenated rapidly (within 10 s) to furnish the bridgehead olefins 13b and 12c. The accompanying hydrogenation enthalpies are -220 and -141 kJmol(-1), respectively. Strain energies (SE) and olefinic strains (OS) of a number of bridgehead olefins have been evaluated by DFT calculations; it was concluded that 13b belongs to the class of hyperstable olefins which correlates nicely with its reluctance to undergo hydrogenation. By combining experimental hydrogenation enthalpies and DFT calculations, SE of 187 and 121 kJmol(-1) were derived for 1b and 1c.
authors.affiliation: Scheikundig Laboratorium, Vrije Universiteit, Amsterdam, The Netherlands.
authors.lastname: van Eis MJ
authors.initials: GW
authors.lastname: Wijsman
authors.lastname: de Wolf WH
authors.initials: F
authors.lastname: Bickelhaupt
authors.initials: DW
authors.lastname: Rogers
authors.initials: H
authors.lastname: Kooijman
authors.initials: AL
authors.lastname: Spek