Acrylonitrile dimerisation using phosphinite or phosphonite catalyst - and protonic solvent, yielding mainly 1,4-di:cyano-butene

摘要

Acrylonitrile (I) is dimerised into 6C linear dimers by contacting (I) with a trivalent organic P cpd. (II), (I) being dissolved in a protonic solvent which is inert to (I) and (II) under dimerisation conditions and (I) and (II) being dry. (II) is of formula X-Ar-P(Ar)-OR, (X-Ar)2-P-OR or X-Ar-P-(OR)2 (where Ar is an aromatic group; each X is an electron donor substituent in p- or m-position giving rise to negative Hammet constant 6; and R is (cyclo)alkyl). Pref. (one) X is in p-position; Ar is phenyl; and X is alkoxy or alkylamino. Pref. (II) is isopropyl bis(p-methyl-phenyl)phosphinite. Use of (II) increases the speed of the reaction. Selectivity is >90%.