%0 Journal Article
%T Isotopic Labeling Study of the Formation of Calix[5]pyrroles Catalyzed by Bi(NO3)3
%A Luis Chac¨®n-Garc¨ªa
%A Claudia A. Contreras-Celed¨®n
%A Melissa Tapia-Ju¨¢rez
%J Catalysts
%D 2013
%I MDPI AG
%R 10.3390/catal3030588
%X One of the more elusive classes of macrocycles includes the calix[5]pyrroles, which can be obtained from pyrrole and acetone in the presence of low concentrations of Bi(NO 3) 3-5H 2O. An isotopic labeling experiment aided the proposal of a mechanism to explain the formation of calix[5]pyrrole at low acid concentrations and the exclusive formation of calix[4]pyrrole at high acid concentrations. We assume that the mechanism involves HNO 3, which is released from the Bi salt.
%K calixpyrrole
%K calix[5]pyrrole
%K bismuth nitrate
%K anion-guest
%U http://www.mdpi.com/2073-4344/3/3/588