POLYMER-SUPPORTED LEWIS-ACID CATALYSTS .7. POLYSTYRENE-BONDED TI(IV) CHLORIDE CATALYSTS

A polystyrene-bonded Ti (IV) chloride catalyst was synthesized by the reaction of a polystyryl lithium (catalyst I, PS-TiCl2) or a polystyry l magnesium (catalyst II, PS-TiCl3) combined with titanium tetrachlori de. The catalyst produced is a polymeric organometallic compound conta ining 0.479 mmol Ti/g catalyst, 0.986 mmol Cl/g catalyst (catalyst I) and 0.281 mmol Ti/g catalyst, 0.766 mmol Cl/g catalyst (catalyst II), depending on the method of synthesis. Both catalysts showed very good stability and good catalytic activity in such organic reactions as est erification, acetalation, and ketal formation. They can be reused many times without losing its catalytic activity. (C) 1993 John Wiley & So ns, Inc.