tert-Butyl-Substituted Tripyrranes: Insights into the Steric and Conformational Factors that Influence Porphyrinoid Ring Formation in the “3+ 1” Methodology

W Jiao, TD Lash

Index: Jiao, Wenhua; Lash, Timothy D. Journal of Organic Chemistry, 2003 , vol. 68, # 10 p. 3896 - 3901

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Citation Number: 26

Abstract

The MacDonald “3+ 1” route for porphyrinoid synthesis involves the acid-catalyzed condensation of tripyrranes with monocyclic dialdehydes, followed by an oxidation step. In the present study, yields were found to be greatly diminished when tert-butyl substituents were introduced on to the tripyrrane unit. Analysis of the proton NMR spectra for the tripyrranes indicates that the preferred conformation in solution has been radically altered ...