SUPPORTED CHIRAL AMINO-ALCOHOLS AND DIOLS FUNCTIONALIZED WITH ALUMINUM AND TITANIUM AS CATALYSTS OF DIELS-ALDER REACTION

Several chiral amino alcohols are supported on chloromethylated polyst yrene-divinylbenzene and treated with AlEtCl(2). The supported catalys ts are far more active than the corresponding homogeneous which is exp lained by site isolation. The catalyst derived from (S)-prolinol leads to a 14% e.e. Tartaric acid supported on polystyrene-divinylbenzene b y means of two ester linkages is treated with aluminium and titanium d erivatives. The aluminium catalyst yields a 13% e.e. and the titanium one can be recovered and reused. The different behaviour of homogeneou s and heterogeneous systems is discussed. Copyright (C) 1996 Elsevier Science Ltd