59452-83-4Relevant academic research and scientific papers
Hydrolysis of Diarylphosphinic Amides in Acidic Solution: Steric Inhibition and Mechanism
Harger, Martin J. P.
, p. 154 - 160 (2007/10/02)
The pseudo-first-order rate constants for the hydrolysis of diphenylphosphinic amide Ph2P(O)NH2 and its di-p-tolyl, di-o-tolyl, and dimesityl analogues (106kψ 3 630, 2 340, 81.0, and 3.27 s-1 respectively with H(1+) 0.0662M and T 30.2 deg C) in water-dioxan (9:1 v/v) containing perchloric acid show that reaction is sterically hindered by ortho-methyl substituents in the P-aryl groups.Steric inhibition is as great, or greater, in the hydrolysis of the corresponding (N-phenyl)diarylphosphinic amides (106kψ 5 440, 4 470, 54.9 and 0.88 s-1 respectively with H(1+) 1.36M and T 39.9 deg C) and (N-p-nitrophenyldiarylphosphinic amides (106kψ 724, 702, 6.57, and 0.098 s-1 respectively with H(1+) 2.58M and T 39.9 deg C) even though the departing amine is less nucleophilic.Such sensitivity to steric hindrance is consistent with associative (A2) mechanism for the hydrolysis of all the substrates.
