Synthesis and Conformational Studies of 2,11-Dithia[3]Metacyclo-[3](1,3)Pyrenophanes: The Ring Current Interactions Derived from Pyrene Ring

Abstract

A series of 2,11-dithia[3]metacyclo[3H1,3)pyrenophanes are obtained by the coupling reaction of the corresponding 1,3-bis(bromomethyl)pyrene and bis(sulfanylmethyl)benzenes in ethanol under the high dilution conditions. The conformational studies of dithia[3]metacyclo[3H1,3)pyrenophanes as well as the ring current interactions derived from pyrene ring are described.

Synthesis of 8-methyl[2.2]metacyclophanes and their charge-transfer complexes with tetracyanoethylene

“…In the 1 H NMR spectra of 5a-f, the signals of the internal aromatic protons at 16 position and the methyl protons at 8-position are shifted to higher magnetic field by 3.10-3.58 ppm (d 2-ArH 7.00 ppm for 1,3-dimethyl-5-tertbutylbenzene) and 1.19-1.80 ppm (d 5-Me 2.28 ppm for 1,2,3,5tetramethylbenzene), respectively. 22 We have evaluated the substutuents effect of the 13-substituents by the chemical shift differences Dd 16-H and Dd 8-Me in comparison of the internal aromatic protons at 16 position and the methyl protons at 8-position of 5b-f with those of 5a. The introduction of the electron-donating group such as methyl, tert-butyl and methoxy group, caused the increase of the ring-current shielding of the internal aromatic protons at 16-position by Dd 8-Me + 0.23-0.41 ppm attributable to the increased pelectrons density of the opposing benzene ring by the throughspace electronic interaction.…”

Synthesis and conformational studies of 9-substituted [3.3]metacyclophane-2,11-diones and conversion to the corresponding [3.3]metacyclophanes

“…All melting points are uncorrected. 1 H NMR spectra were recorded at 300 MHz on a Nippon Denshi JEOL FT-300 NMR spectrometer in deuteriochloroform with Me 4 Si as an internal reference. IR spectra were measured as KBr pellets on a Nippon Denshi JIR-AQ2OM spectrometer.…”

“…Key compounds that have been prepared before should be given the appropriate reference and the relevant literature physical data, such as the melting point, should be quoted for comparison. 1 H NMR shifts should be quoted to two decimal places. The multiplicity, relative integrals, and J values should be quoted and assignments given where possible.…”

“…The synthesis and stereochemical aspects of conformationally mobile [3.3]MCPs (MCP = metacyclophane) have been of interest for the past decade, with particular attention [1][2][3] paid to dithia[3.3]MCPs, which possess an anti-stepped conformation. The pioneering work of the conformational investigation of 2,11-dithia[3.3]MCPs was reported by Vögtle et al 4 Shinmyozu and his co-workers 5 preparation and conformational behaviour in the carbocyclic [3.3]MCPs and their analogues.…”

“…-to-syn ratios in TosMIC cyclisation of 2 with 3 a Isolated yields. b anti-to-syn ratios determined by1 H NMR spectroscopy at 20°C…”