Orthomercurated and cycloaurated derivatives of the iminophosphorane Ph3PNPh

Abstract

Ortho-lithiation of Ph 3 P=NPh followed by reaction with HgCl 2 gave good yields of [Hg{C 6 H 4 (PPh 2 =NPh)-2}Cl], 3, which was characterised spectroscopically and by an Xray crystal structure determination. This is an isomer of the product of direct mercuration of Ph 3 P=NPh which occurs on the N-bonded phenyl ring [Vicente et al, Organometallics, 22 (2003) 4248]. Transmetallation of 3 with [AuCl 4 ]gave the corresponding cycloaurated complex [Au{ 2-C,N-C 6 H 4 (PPh 2 =NPh)-2}Cl 2 ], with a five-membered metallocyclic ring incorporating four different elements.

Cyclometalated gold(III) iminophosphoranes which incorporate carbohydrate groups

“…The trans influence can be seen in the lengthening of the AueCl bond trans to the carbon compared with that opposite the N (2.348(2) Å compared with 2.272(2) Å) for 6a. The bonding parameters involving Au are similar to those reported for (2-Cl 2 AuC 6 H 4 )Ph 2 P]NePh, as are the CeN and N]P bond lengths [6].…”

“…Monitoring of the reaction by 31 P NMR and ESI-MS showed that the intermediate mercurated iminophosphorane, 5a, had fully formed after 1.5 h. Removal of the solvent gave 5a which was used directly, after characterisation by 31 P NMR and ESI-MS. The ion [AuCl 4 ] À has been used to produce gold(III) iminophosphoranes [6,17,30]. To 5a was added [NMe 4 ][AuCl 4 ] and dry acetonitrile and the mixture stirred for several days in the dark.…”

“…The nitrogen is displaced from this plane by 0.411(7) Å. While there are examples of iminophosphoranes having a near-planar metallocyclic ring, such as [2-(CO) 4 MnC 6 H 4 ]Ph 2 P] NePh [5], all reported Au(III) compounds give envelope conformations with the nitrogen atom out of plane [6,17].…”

“…Direct cyclometallation has also been carried out with Pd(OAc) 2 or Hg(OAc) 2 [4] and with PhCH 2 M(CO) 5 (M ¼ Mn or Re) [5]. An indirect route where the iminophosphorane is initially lithiated and then transmetalated has been used to prepare gold [6,7], rhodium, iridium [8], aluminium and gallium [9] cyclometalated iminophosphoranes. We have been particularly interested in cycloaurated iminophosphoranes, since the ligand is effective at stabilising the gold(III) oxidation state.…”

Cytotoxic hydrophilic iminophosphorane coordination compounds of d8 metals. Studies of their interactions with DNA and HSA

“…We and others have reported on the biological [15–18] and catalytic [19–21] applications of iminophosphorane or iminophosphine derivatives of gold(III) (selected examples in Fig. 1) [15,16].…”