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The structures of coordination complexes of methylmagnesium chloride with 1‐halogen‐3‐methoxy‐1‐propynes have been studied by means of ab initio methods (RHF/3‐21G*, RHF/6‐31G* and RHF/6‐31G**), taking into account the electron correlation by Møller‐Plesset perturbation theory (MP2). Two pathways of the nucleophilic halogen substitution reaction between the reagents have been considered. The calculations predict the addition–elimination mechanism as advantageous for the reaction. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2005 [ABSTRACT FROM AUTHOR]

The threecomponent reactions of 1azabicyclo1.1.0butanes 1, dicyanofumarates E5, and MeOH or morpholine yielded azetidine enamines 8and 9with the cisorientation of the ester groups at the CC bond Econfiguration; Schemes3and 4. The structures of 8aand 9dwere confirmed by Xray crystallography. The formation of the products is explained viathe nucleophilic addition of 1onto E5, leading to a zwitterion of type 7Scheme2, which is subsequently trapped by MeOH or morpholine 10a, followed by elimination of HCN. Similarly, twocomponent reactions between secondary amines 10a–10cand E5gave products 12with an Eenamine structure and Zoriented ester groups. On the other hand, twocomponent reactions involving primary amines 10d–10for NH3led to the formation of the corresponding Zenamines, in which the Eorientation of ester groups was established. [ABSTRACT FROM AUTHOR]