Multiple Aromatic Amination Mediated by a Diiron Complex

Abstract

Stop‐frame amination: A very efficient amine transfer reaction is mediated by a biomimetic diiron complex, giving both single and double insertions of a tosylamine group into a pendant benzyl group of the ligand (see structure). The monoinsertion product has been shown by X‐ray crystallography and other physical methods to be a tosylanilinato diiron(III) complex.

A Useful Route to Metal Complexes of Poorly Coordinating Sulfonamides

“…The structure of Pd(L Ts ) 2 shows a quasi-square-planar complex, in which the palladium ion practically acts as an inversion centre; therefore, the complex presents a trans configuration of the donor atoms, whereas both tosyl groups display an anti disposition with an opposite orientation with respect to the coordination plane. This spatial arrangement means that both N sulfonamide atoms display opposite configurations, R and S. Hence, the inversion of these N atoms would entail the consequent change in the disposition of the corresponding tosyl groups.…”

“…This packing scheme is in clear contrast with the typical H-bonded dimers formed by both enantiomers in achiral crystals. [22] Crystal Structure of trans-Pd(L Ts ) 2 Pd(L Ts ) 2 , which is represented as an ORTEP diagram with the corresponding labelling scheme in Figure 4, crystallises in the centrosymmetric space group P1. The asymmetric unit contains a whole molecule of the neutral complex, and both ligands are monoanionic after deprotonation of their sulfonamide groups.…”

“…This spatial arrangement means that both N sulfonamide atoms display opposite configurations, R and S. Hence, the inversion of these N atoms would entail the consequent change in the disposition of the corresponding tosyl groups. The main bond lengths and angles of trans-Pd(L Ts ) 2 , which are collected in Table 2, are not exceptional; [16][17][18][19][20][21][22][23][24] however, the torsion angles deserve some attention, as the torsion of the aryl groups appears to be a crucial factor for molecular recognition in the medicinal chemistry of sulfonamides. [15] Thus, after coordination to the palladium(II) ion, the conformation adopted by the tosyl groups significantly differs from that considered as preferred.…”

“…The investigation was initiated by the attempted electrochemical oxidation of Zn or Cd metal anodes in a solution of HL Ts at room temperature and by the direct reaction of HL Ts with M(OAc) 2 (M = Zn and Cd) under reflux. However, these two synthetic approaches did not allow the isolation of any significant amounts of the corresponding metal complexes.…”

“…Many important catalysts [1][2][3] and drugs [4][5][6][7][8] contain sulfonamide groups. Among the different classes of sulfonamide drugs, those with nuclease and/or cytotoxic activity are receiving increasing attention in the search for anticancer chemotherapeutic strategies.…”