Organoaluminum-mediated polymerization of diazoketones

Abstract

Polymerization of diazoketones mediated by organoaluminum compounds was investigated. Trialkylaluminum R3Al (R = iBu, Et, Me) and diisobutylaluminum hydride (DIBAL) polymerized (E)-1-diazo-3-nonen-2-one (1) to give polymers with Mn = 2000-3500, which contained nearly 33 mol% of azo group (-N=N-) along with the dominant acylmethylene unit in the main chain. On the other hand, when (E)-1-diazo-4-phenyl-3-buten-2-one (2) was used as a monomer for the organoaluminum-mediated polymerization, the resulting polymers had ethylidene (-CH[CH3]-) units in the main chain along with acylmethylene and azo group, as a result of reductive cleavage of the acyl group during the polymerization. © 2007 Wiley Periodicals, Inc.