Substituent effect of (triphenylphosphinemethylene)boranes on latent catalytic activity for polyaddition of bisphenol a diglycidyl ether with bisphenol A: Model system of epoxy-novolac resin

The substituent effect of (triphenylphosphinemethylene)boranes, Ph3P-CH(R')-BR3 [(triphenylphosphinemethylene)borane I-H), (triphenylphosphineformylmethylene)trifluoroborane (IIF), (triphenylphosphineacetylmethylene)trifluoroborane (IIIF), (triphenylphosphineacetylmethylene)triphenylborane (IIIPh), and (triphenylphosphinacetylmethylene)borane (IIIH)], as thermally latent catalysts was examined in the polyaddition of bisphenol A diglycidyl ether with bisphenol A. Introduction of an acyl group on the ylide moiety was effective to enhance the catalytic activity. Thermal latency of the (triphenylphosphinemethylene)boranes was discussed from the viewpoint of the catalytic mechanism with the substituent effect on both ylide and borane.