Polymer-Supported (Salen)Al Catalysts

Significance

A highly active polymer-supported (salen)Al catalyst for the enantioselective addition of cyanide to α,β-unsaturated imides was developed. Thus, the salen ligand 2 was prepared from the optically active diamine monohydrochloride 1 in three steps. After the complexation of 2 with Et₂AlCl, the resulting (salen)Al complex 3 was subjected to the ring-opening-metathesis polymerization to give the polymer-supported (salen)Al complex 4. The reaction of α,β-unsaturated imides 5 with TMSCN was conducted in toluene in the presence of 4 to give the corresponding adducts 6 in 88-96% yield with 98-99% ee.