Selective dimerisation of 1-butene in biphasic mode using buffered chloroaluminate ionic liquid solvents - design and application of a continuous loop reactor

The dimerisation of 1-butene using (cod)Ni(hfacac)(1) under bar as catalyst has been investigated in different chloroaluminate ionic liquids. Systems prepared by buffering an acidic ionic liquid with weak organic bases proved to be very suitable solvents for the reaction. The reaction takes place in biphasic reaction mode with facile catalyst separation and catalyst recycl ing. The high intrinsic dimer linearity of catalyst (1) under bar is mainta ined, but with significant enhancement of catalyst activity and of the sele ctivity to the dimer product over that observed in toluene solvent. For fur ther investigation, a continuous reactor was designed. Our results in conti nuous mode show the general technical applicability of the selective Ni-cat alysed dimerisation in chloroaluminate ionic liquids using a loop reactor c oncept. (C) 2001 Elsevier Science B.V. All rights reserved.