Iron salen-catalysed oxidative coupling of phenol derivatives: formaldehyde-free access to amphiphilic polymers.

The oxidative coupling of 4- tert-butylphenol ( 1), 2,6-di- tert-butyl- p-cresol ( 11) and 4-cyanophenol ( 10) in the presence of iron salen catalysts (salen = N, N′-bis(salicylidine)ethylenediamine) and the influence of amine additives on the conversion of 1 were investigated. Furthermore, the activity of the iron complexes was correlated with the substituents at the 5,5′-positions of the salen ligands. Mechanistically conclusions based on dimer formation in the reaction between 10 and 11 are presented. In the second part of the study the obtained hydrophobic poly(4- tert-butylphenol) was modified with Jeffamine^® M-600, M-1000 or M-2070 to give amphiphilic copolymers (18a-c). The amphiphilic copolymers were characterized via size-exclusion chromatography and dynamic light scattering. The concentration dependence of the cloud point appearance in water of amphiphilic copolymer 18c was analysed via turbidity measurements. © 2016 Society of Chemical Industry [ABSTRACT FROM AUTHOR]