Cyclo-oligomerization of isocyanates with Na(PH₂) or Na(OCP) as "P^-" anion sources.

ABSTRACT: We show that the 2-phosphaethynolate anion, OCP^-, is a simple and efficient catalyst for the cyclotrimerization of isocyanates. This process proceeds step-wise and involves five-membered heterocycles, namely 1,4,2-diazaphospholidine-3,5-dionide anions and spiro-phosphoranides as detectable intermediates, both of which were also found to be involved in the catalytic conversion. These species can be considered as adducts of a phosphide anion with two and four isocyanate molecules, respectively, demonstrating that the OCP^- anion acts as a formal "P^-" source. The interconversion between these anionic species was found to be reversible, allowing them to serve as reservoirs for unique phosphorus-based living-catalysts for isocyanate trimerization.

SUBMITTER: Heift D 

PROVIDER: S-EPMC5497264 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature