Calixpyrroles II

This review article is the second in a series covering advances in the synthetic and molecular recognition chemistry of calixpyrrole macrocycles (meso-octasubstituted porphyrinogens). Significant progress has been made in the last three years in the use of calix[4]pyrroles as redox-active or optical sensors for anions. This period has also been marked by a number of preparative advances, including the synthesis of N-confused calix[4]pyrroles, the synthesis of extended cavity calix[4]pyrroles, and the synthesis of 'higher order' or 'expanded' calix[n]pyrroles (n > 4). (C) 2001 Elsevier Science B.V. All rights reserved.