e.g. Filippa Pettersson or Cancer Res. 75(6) , 1102-12, (2015) or 10.1002/anie.201600521
The Journal of organic chemistry
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
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 ...