A regioselective synthesis of novel oxo-thioxo[3.3.3]propellanes

Propellane is a special kind of fused tricyclic system containing three non-zero bridges and one zero bridge between a pair of bridgehead carbon atoms [1]. This skeleton has received much attention in synthetic organic chemistry due to their fascinating topology, significant chemical and physical properties and their presence in several natural products and bioactive compounds [2]. In recent years, various protocols for the synthesis of propellanes have been described [3]. Herein, we report a new method for the synthesis of novel oxo-thioxo[3.3.3]propellanes 3 by a one pot three-component reaction involving aliphatic and aromatic amines 2, carbon disulfide, and the Knoevenagelcondensation product of ninhydrin and malononitrile 1 in CH2Cl2, in the presence of Et3N, at room temperature (Fig. 1). The structures of products were characterized by their IR, 1H NMR, 13C NMR and mass spectral data. Various advantages of these transformations will be presented and discussed