N-TOSYLATED POLYAZA[N](1,4)NAPHTHALENOPHANES - SYNTHESIS AND CONFORMATIONAL STUDIES

Citation
Mi. Burguete et al., N-TOSYLATED POLYAZA[N](1,4)NAPHTHALENOPHANES - SYNTHESIS AND CONFORMATIONAL STUDIES, Journal of organic chemistry, 59(5), 1994, pp. 1067-1071
Citations number
40
Categorie Soggetti
Chemistry Inorganic & Nuclear
ISSN journal
00223263
Volume
59
Issue
5
Year of publication
1994
Pages
1067 - 1071
Database
ISI
SICI code
0022-3263(1994)59:5<1067:NP-SAC>2.0.ZU;2-J
Abstract
N-Tosylated polyaza[n](1,4)naphthalenophanes containing from 3 to 6 ni trogen atoms and from 9 to 18 atoms in the saturated bridge can be pre pared in high yields from 1,4-bis(bromomethyl)naphthalene and the appr opriate N-tosylated polyamine chains. NMR data and molecular mechanics calculations suggest the prevalence of conformations in which the pol yamine bridge is located above the aromatic ring. Variable-temperature NMR experiments show that internal rotation of the aromatic ring is n ot allowed, on the NMR time scale, even at 180 degrees C for naphthale nophanes having chain lengths of 12 or less. For naphthalenophanes wit h chain lengths of 14 or 15 atoms, the rotational barrier is on the or der of 12 kcal mol(-1) as calculated from VT-NMR data.