Synthesis of new azido porphyrins and their reactivity in copper(I)-catalyzed Huisgen 1,3-dipolar cycloaddition reaction with alkynes

We report herein the preparation of two novel porphyrins substituted with an azido group born either on the para-position of one phenyl meso-susbtituent of a tetraaryl zinc porphyrin (1) or directly on the meso-position of a trisaryl nickel porphyrin (2). We studied the scope and the limitation the Huisgen cycloaddition reaction of these two porphyrins using different catalytic conditions. We observed that the carbene (SlMes)CuBr in THF/H2O 3:1 at 45 degrees C for 60 h gives almost quantitative yields for the reaction between I and different alkynes, but significantly lower yields with 2 probably due to its thermal instability. (c) 2007 Elsevier Ltd. All rights reserved.