Mono-Alkyl-Substituted Phosphinoboranes (HRP–BH2–NMe3) as Precursors for Poly(alkylphosphinoborane)s: Improved Synthesis and Comparative Study

A new synthetic pathway to various mono-alkyl-substituted phosphinoboranes HRP–BH2–NMe3 has been developed. The route starting from alkyl halides and NaPH2 followed by metalation salt metathesis is performed in a one-pot procedure leads higher yields purity of the resulting phosphinoboranes, as compared previously reported routes. Additionally, scope accessible compounds could be expanded short-chained linear substituents longer-chained well secondary or functionalized substituents. examples include primary alkyl-substituted RHP-BH2-NMe3 (R = n-butyl, n-pentyl, n-hexyl; 1a–c), derivatives iPrPH-BH2-NMe3 (2), 4-bromo-butyl-phosphinoborane (BrC4H8)PH-BH2-NMe3 (3). Compounds 1a, 1c, 2 were additionally used for preliminary polymerization reactions via thermal transition metal-catalyzed pathway, revealing formation high-molecular-weight polymers under certain conditions. Detailed investigations on influence temperature, concentration, reaction time respective performed.