New Process for the Sulfonation of Phosphane Ligands for Catalysts

摘要

Two-phase procedures have opened a new perspective for organometallic homogeneous catalysis as exemplified in hydro-formylation. Sulfonated phosphane ligands have proved themselves in the Ruhrchemie/Rhone-Poulenc process| and suggest that a large potential may be anticipated for other C-C coupling reactions, too. Fuming sulfuric acid (oleum), often the only effective sulfonating agent for arylphosphanes is not always satisfactory as a reagent for synthesis: parallel to the sulfonation of the aryl groups it also causes the formation of undesirable phosphane oxides, which, according to our present understanding, are useless for catalytic purposes and, in addition, are laborious to separate.