Regio- and Stereoselective 1,3-Dipolar Cycloaddition of Cyclic Azomethine Imines to Platinum(IV)-Bound Nitriles Giving Delta super(2)-1,2,4-Triazoline Species

The complex trans[ PtCl[sub 4](EtCN)[sub 2]] (14) reacts smoothly at 25 [degrees]C with the stable cyclic azomethine imines (ProQuest: Formulae and/or non-USASCII text omitted) and the reaction proceeds as stereo-selective 1, 3-dipolar cycloaddition to one of the EtCN ligands accomplishing the monocycloadducts trans. Inspection of the obtained and literature data indicate that the cycloaddition of the azomethine imines to the C [congruence] N bonds of HCN and of Pt[supIV]-bound EtCN has different regio-selectivity leading to [Delta [sup 2]] 1, 2, 3-triazolines and [Delta [sup 2]] 1, 2, 4-triazolines, respectively. Theoretical density functional theory calculations were carried out for the investigation of the reaction mechanism, interpretation of the reactivity of Pt-bound and free nitriles toward azomethine imines and analysis of the regio- and stereo-selectivity origin.