Beilstein J. Org. Chem.2009,5, No. 74, doi:10.3762/bjoc.5.74
Institut de Chimie des Substances Naturelles, C.N.R.S., 91190 Gif-sur-Yvette, France 10.3762/bjoc.5.74 Abstract The synthesis of [3.3]dithia-bridgedcyclophanes 7, 9 and 11 incorporating a fused heterocycle, thieno[2,3-b]thiophene is described. The structures are established by 1H NMR analysis and, in the
]dithia-bridgedcyclophanes; dynamic NMR analysis; thieno[2,3-b]thiophene; X-ray crystal structure; Introduction
The synthesis, molecular structures and conformational dynamics of short-bridged cyclophanes continue to engage interest in supramolecular chemistry [1][2][3][4]. The study of the
. Although, the computed energy difference between the most stable conformation anti-11 and the next higher energy conformation syn-anti-11 is only 2.98 kJ/mol, it is intriguing that 11 does not exhibit thia-bridge inversion even at elevated temperatures.
Keywords: conformational energy minimization; [3.3