Stereoselective Synthesis of Imidazolines

When the cyclization reaction was performed in the presence of Pd(OAc)2 using a phenyl suhbnimine (2, Q = Ph) substrate, the imidazoline product (4, Ar= Ph) was formed with poor regioselectivity (Table 4.1). However, use of the PCP complex la led to excellent regioselectivity with a syn/anti ratio of 10 1. This indicates that pincer complexes are more efficient catalysts for the cyclization reactions than simple palladium salt, as both the selectivity and the yield could be improved using la. 

The reaction had a broad synthetic scope, as imines substrates with aromatic (4a-d), heteroaromatic (4e), and vinyl (4f) substituents gave high yield. Using the 

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