Jm. Fraile et al., SUPPORTED CHIRAL AMINO-ALCOHOLS AND DIOLS FUNCTIONALIZED WITH ALUMINUM AND TITANIUM AS CATALYSTS OF DIELS-ALDER REACTION, Tetrahedron, 52(29), 1996, pp. 9853-9862
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