Phosphine catalyzed reduction of CO2 with boranes

Abstract

Phosphine is shown to catalyse the reaction of CO₂ with 9-BBN to give mixtures of HCO₂(B(C₈H₁₄)) 3, H₂C(OB(C₈H₁₄))₂4 and MeOB(C₈H₁₄) 5; at 0.02 mol% of tBu₃P 5 is obtained in 98% yield at 60 °C with TON of almost 5500 and a TOF of 170. Under stoichiometric conditions the species (R₃PCH₂O)(HC(O)O)B(C₈H₁₄) (R = tBu 1,4-MeC₆H₄2) were isolated and characterized.