title: Reduction of strained polycycles: how much strain can a pyrene anion take?
abstract: The reduction of a series of [n](2,7)pyrenophanes (n = 7-10) with lithium or potassium metal shows that the strain in the system, controlled by the length of the tether, determines the nature of the reduction products. The reduction of [7](2,7)pyrenophane (2) and [2]metacyclo[2](2,7)pyrenophane (3) leads to reductive dimerization followed by novel intramolecular sigma-bond formation as a means of escaping strained anti-aromaticity. [8](2,7)Pyrenophane (4) affords only reductive dimerization, and no two-electron reduction is observed. The reduction of [9](2,7) pyrenophane (5) and [10](2,7)pyrenophane (6) leads to reductive dimerization, followed by the formation of a dianionic anti-aromatic species, which eventually cleaves the solvent, THF-d(8). The similarity between the reduction of the latter systems and the reduction of pyrene (1) is discussed.
authors.affiliation: Department of Organic Chemistry, The Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Ivan
authors.initials: I
authors.lastname: Aprahamian
authors.forename: Graham J
authors.initials: GJ
authors.lastname: Bodwell
authors.forename: Jim J
authors.initials: JJ
authors.lastname: Fleming
authors.forename: Greg P
authors.initials: GP
authors.lastname: Manning
authors.forename: Michael R
authors.initials: MR
authors.lastname: Mannion
authors.forename: Brad L
authors.initials: BL
authors.lastname: Merner
authors.forename: Tuvia
authors.initials: T
authors.lastname: Sheradsky
authors.forename: Rudolf J
authors.initials: RJ
authors.lastname: Vermeij
authors.forename: Mordecai
authors.initials: M
authors.lastname: Rabinovitz