P4-t-Bu is one of the strongest neutral nitrogenous bases with an extrapolated pKa value of 42.1 in acetonitrile and is compared to the strong base DBU with a pKa value of 24.3 by 18 orders of magnitude more basic [REF].
P4-t-Bu is an extremely hygroscopic solid which is thermally stable up to 120 °C and chemically stable to (dry) oxygen and bases [REF].