Metal-Free Ring-Opening Metathesis Polymerization with Hydrazonium Initiators

Phong K Quach; Jesse H Hsu; Ivan Keresztes; Brett P Fors; Tristan H Lambert

doi:10.1002/anie.202203344

Metal-Free Ring-Opening Metathesis Polymerization with Hydrazonium Initiators

Angew Chem Int Ed Engl. 2022 Jun 13;61(24):e202203344. doi: 10.1002/anie.202203344. Epub 2022 Apr 13.

Authors

Phong K Quach¹, Jesse H Hsu¹, Ivan Keresztes¹, Brett P Fors¹, Tristan H Lambert¹

Affiliation

¹ Department of Chemistry and Chemical Biology, Cornell University, 122 Baker Laboratory, Ithaca, NY 14853, USA.

Abstract

The ring-opening metathesis polymerization (ROMP) of cyclopropenes using hydrazonium initiators is described. The initiators, which are formed by the condensation of 2,3-diazabicyclo[2.2.2]octane and an aldehyde, polymerize cyclopropene monomers by a sequence of [3+2] cycloaddition and cycloreversion reactions. This process generates short chain polyolefins (M_n ≤9.4 kg mol^-1 ) with relatively low dispersities (Đ≤1.4). The optimized conditions showed efficiency comparable to that achieved with Grubbs' 2^nd generation catalyst for the polymerization of 3-methyl-3-phenylcyclopropene. A positive correlation between monomer to initiator ratio and degree of polymerization was revealed through NMR spectroscopy.

Keywords: Carbonyl-Olefin Metathesis; Cyclopropene; Polymerization; ROMP; Ring-Opening Metathesis Polymerization.

Abstract

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