Stereoselective nitrilimine cycloadditions to the C=N bond of enantiopure N-(1-phenylethyl)-1-arylmethanimines

Diastereoselective 1,3-dipolar cycloadditions between C-methoxycarbonyl-N-arylnitrilimines 2 and the C=N bond of enantiopure N-(1-phenylethyl)-1-arylmethanimines 3 gave diastereoisomeric 5-aryl-4,5-dihydro- 1,2,4-triazolines 4 and 5. A computational description of the E --> Z isomerisation of the C=N bond of unsubstituted 3a is given