210303-87-0Relevant articles and documents
Polyaza[n](1,4)naphthalenophanes and polyaza[n](9,10)anthracenophanes
Burguete, M.Isabel,Escuder, Beatriu,García-Espa?a, Enrique,Luis, Santiago V,Miravet, Juan F
, p. 2839 - 2846 (2007/10/03)
A series of polyaza[n](1,4)naphthalenophanes and polyaza[n](9,10)anthracenophanes have been prepared by using the Fukuyama's protecting group (2- or 4-nitrophenyl sulfonyl) in a one-pot cyclization-deprotection reaction. Global yields for the purified products are comparable with those obtained for other polyazacyclophanes using the tosyl group as the amine protecting group. Their structural study has been carried-out by NMR showing a high rigidity for the smaller cycles and a more dynamic behaviour for the largest member of the series. The free energy barrier for the rotational equilibrium for compound 25 is about 3kcal/mol lower than that calculated for analogous N-tosylated macrocycles.