Catalytic asymmetric heterogeneous aziridination of styrene derivatives using bis(oxazoline)-modified Cu2+-exchanged zeolite Y.

The copper-catalysed aziridination of styrene derivatives using either Cu(OTf)2 as a homogeneous catalyst or copper-exchanged zeolite Y modified as a heterogeneous catalyst with bis(oxazoline) using [N-(p-nitrophenylsulfonyl)imino]phenyliodinane (PhI=NNs) as nitrene donor is described and discussed. For the homogeneously catalysed reaction virtually all the substituted derivatives gave lower yields of the aziridine with lower ee when compared with styrene, although 4-chlorostyrene did give enhanced ee. For the heterogeneous catalysed reaction the styrene derivatives often gave enhanced yield, particularly when the substituent was in the 4-position.

Observation of the enhancement in enantioselectivity with conversion for the aziridination of styrene using copper bis(oxazoline) complexes.

During the aziridination of styrene using copper bis(oxazoline) complexes the ee increases with conversion due to further reactions of the product.