| 摘要 |
Chiral Schiff bases according to the general formula: <IMAGE> and transition metal complexes thereof, wherein C* is an asymmetric carbon atom, R1 and R2, which may be the same or different are alkyl, aralkyl, aryl or alkaryl, R3 is hydrogen, alkyl, aralkyl, aryl or alkaryl, R4 and R5, which may be the same or different, are hydrogen or lower alkyl or, where n is 1, may with the cyclic ring to which CR4R5 is attached form a fused system, J is a chain of 3 or 4 atoms which may all be carbon atoms or may be a mixture of carbon atoms and one or more hetero atoms which may be the same or different, which chain with the group C K forms an aromatic system, K is nitrogen, <IMAGE> or -NH-, L, each of which may be the same or different, represents a substituent attached to a carbon atom in the chain J and is hydrogen, alkyl, aralkyl, alkaryl, aryl or a substituent containing a hetero-atom; or two L's together with the cyclic ring to which they are attached form a fused system, n is 0, 1 or 2, m is the number of carbon atoms in the chain J. The transition metal is for example copper (II), chromium (II), manganese (II), iron (II), cobalt (II) nickel (II) or palladium (II). The aforesaid complexes may be used as catalysts in the cyclopropanation of olefins by diazoacetates to form insecticide or insecticide precursors.
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