Batchwise and Continuous Organophilic Nanofiltration of Grubbs-Type Olefin Metathesis Catalysts

摘要

A mass-tagged N-mesityl imidazolinium salt with four additional -CH2NCy2 substituents was synthesized,leading to a molecular mass of nearly 1100 gmol1 in the corresponding carbene ligand. This mass-tagged ligand was used to generate the respective Grubbs II and GrubbsCHoveyda type complexes. The catalytic activity of the latter complex was tested in several olefin metathesis reactions and found to be slightly superior to that of the related N-mesityl based complex. In batchwise solvent resistant nanofiltration experiments the ruthenium complex dissolved in toluene and following a metathesis reactions was efficiently retained (>99.8%) by a single nanofiltration; the permeate contained less than 4 ppm of Ru. Equally efficient catalyst retention was observed in a membrane reactor utilized for the continuous synthesis of a RCM product.