Aziridination of Conjugated Dienes

The achiral aziridination with the racemic nitrido complex 15 was successfully applied to a wide range of 1,3-dienes (Table 6.6). Cyclic conjugated dienes were smoothly aziridinated under mild conditions with no [4+1] adducts. Among these, cyclohexadiene and cycloheptadiene reacted with the complex in good yields. When the unsymmetrical dienes were employed in the reaction, the aziridi-nations of isoprene and trans-1,3-hexadiene proceeded, giving two regioisomers in 70 30 and 94 6, respectively. The major isomers in both reactions were formed by the aziridination of the less substituted olefins of the 1,3-dienes. 

Alkenyl aziridines are useful synthetic building blocks and can be converted to allylamines by conjugate addition of organocuprates [29], to pyrroline derivatives by rearrangement [30] and to P-lactams by Pd-catalyzed carbonylation [31]. 

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Scheme 2.5) was recently reported by Komatsu, Minakata, and coworkers [12]. The reaction with the (i ,i )-complex 12 provided the first reagent-controlled asymmetric aziridination of conjugated dienes, although enantioselectivities were only low to moderate (20-40% ee). 

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