Synthesis of 1,4-Benzothiazepin-5-ones from N-Tosyl Aziridines and 2-Iodothiophenols

Significance

Based on a precedent (G. Chouhan, H. Alper Org. Lett. 2010, 12, 192), a one-pot ring-opening-carboxamidation reaction sequence of N-tosyl aziridines 1 and 4 with o-iodophenols 2 and 5, leading to 1,4-benzothiazepin-5-ones 3 and 6, is reported. After optimization studies (nature of ligands and inorganic bases, pressure of CO), the scope of the reaction was examined by treatment of o-halothiophenols bearing EDGs and EWGs (X = I or Br) with various saturated or unsaturated cyclic (five-, six-, seven-, and eight-membered ring) and acyclic N-tosyl aziridines. The trans stereochemistry of these products was determined by ^¹H NMR spectroscopy and NOESY experiments.