Aryne chemistry. Part V. Some addition reactions of tetrafluorobenzyne

Abstract

The addition of tetrafluorobenzyne to benzene and mono-, di-, tri-, tetra-, and hexa-alkyl benzenes is described together with the additions to tetralins, naphthalenes and anthracene. In all these reactions only 1,4-addition products are isolated. The pyrolyses of some of the compounds isolated are reported. The proton magnetic resonance spectra of the products and the mass spectra of certain compounds are discussed.

Severe Energy Costs of Double Steric Interactions: Towards a Molecular Clamp

“…Another way to break the threefold symmetry of a triptycene involves the functionalisation of one, or more, of the blades. Although the Diels–Alder addition of tetrafluorobenzyne to anthracene to form 1,2,3,4‐tetrafluorotriptycene ( 11 ) was first reported in 1968,16 we are unaware of any structural characterisation of the parent compound, nor of any 9‐substituted derivatives. The X‐ray crystal structure of 1,2,3,4‐tetrafluorotriptycene is shown in Figure 10, and the geometry deviates only slightly from ideality: the interplanar angle between the two benzo rings (123.1°) is somewhat larger that those between the tetrafluorobenzo ring and its neighbours (120.5° and 116.4°).…”

“…Elemental analyses were carried out by the Microanalytical Laboratory at University College Dublin. Compounds 1a – c ,8 2a ,8a 2b ,8b 10 ,25 11 16 16 ,18 17 ,19 18 and 19 21 were prepared as described elsewhere.…”

Competition between hydrogen bonding and arene–perfluoroarene stacking. X-Ray diffraction and molecular simulation on 5,6,7,8-tetrafluoro-2-naphthoic acid and 5,6,7,8-tetrafluoro-2-naphthamide crystals

“…5,6,7,8-Tetrafluoro-2-naphthoic acid and 5,6,7,8-tetrafluoro-2-naphthamide were prepared according to the reaction sequence reported in Scheme 1. 5,6,7,8-Tetrafluoro-2-methyl-naphthalene 20 was exhaustively brominated with an excess of N-bromosuccinimide in refluxing CCl 4 in the presence of benzoylperoxide to afford the corresponding tribromomethyl derivative in 47% isolated yield. Treatment of this compound with potassium acetate in refluxing acetic acid, followed by hydrolysis with 10% aqueous hydrochloric acid 21 gave 5,6,7,8-tetrafluoro-2-naphthoic acid in 35% yield.…”

(η4-Tetrafluorobenzobarrelene)-η1-((tri-4-fluorophenyl)phosphine)-η1-(2-phenylphenyl)rhodium(I): A Catalyst for the Living Polymerization of Phenylacetylenes

“…The target compound was prepared via a modified approach of previously reported syntheses. 34,35 To a round-bottom flask equipped with a Teflon-coated magnetic stir bar, bromopentafluorobenzene (5 g, 0.02 mol) was added to benzene (63.0 mL, 0.7 mmol) and was stirred for 10 min under a dry nitrogen atmosphere at 0 °C. To this was added n-BuLi (12.5 mL, 0.02 mol) to produce a ethereal light orange solution, which was stirred at 0 °C for 2 h. Subsequently, the solvent was removed via rotary evaporation, yielding an orange residue, which was extracted with hexane and filtered through a column containing neutral activated alumina 90 (80 g, activity I).…”