Syntheses and properties of novel polyphosphines containing various combinations of primary, secondary, and tertiary phosphorus atoms

Abstract

Novel polyphosphines can be prepared by the base-catalysed addition of R₂P–H across the carbon–carbon double bonds of vinylphosphonate esters, followed by reduction with lithium aluminium hydride. Thus a tertiary-primary diphosphine, a tertiary-diprimary triphosphine, a tertiary-triprimary tripod tetraphosphine, and a ditertiary-diprimary linear tetraphosphine have been prepared. Similarly, the tertiary-secondary diphosphine Ph₂P·CH₂·CH₂·PHPh can be prepared by base-catalysed addition of diphenylphosphine to isopropyl phenylvinyl-phosphinate followed by reduction. The secondary-primary diphosphine PhPH·CH₂·CH₂·PH₂ can be prepared by the Arbusov reaction of di-isopropoxy(phenyl)phosphine with di-isopropyl 2-bromoethylphosphonate followed by reduction. The i.r., ¹H n.m.r., ³¹P n.m.r., and mass spectra of the new compounds are discussed.