Platinum(II) and Palladium(II) Compounds Containing Chiral Thioimines

Abstract

A comparative study of the reactivity of the optically pure thioimine:(S C )-(−)-C 6 H 5 −CH=N−CH(CO 2 Me)−CH 2 −CH 2 − SMe (1) versus platinum(II) and palladium(II) salts is reported. The reaction of 1 with cis-[PtCl 2 (dmso) 2 ] leads to the cycloplatinated derivative (S C ,. The absolute configuration of 3a has been established unambiguously by X-ray diffraction: orthorhombic, with a = 8.979 (4), b = 9.605(9), c = 18.205(6) Å , α = β = γ = 90.0°, space group P2 1 2 1 2 1 . Compound 3a contains a [6.5.6] tricyclic system generated by the fusion of a phenyl ring, a five-membered platinacycle and a six-membered chelate ring formed by the coordination of the

Novel Five-Membered Pallada- and Platinacycles Containing a [C(sp2, ferrocene), N, S]- Terdentate Ligand. Theoretical Interpretation of Their Electrochemical and Electronic Properties Based on Density Functional Calculations

“…The 195 Pt{ 1 H} NMR spectrum of 3c showed one signal at δ = −3488 ppm, which is consistent with the range expected for complexes containing a [(C,N,S,Cl] environment around the platinum(II). ,, According to the literature, an upfield shift of the 195 Pt{ 1 H} NMR chemical shift is related to a strong donor interaction, since compounds 3b and 3c differ only in the nature of the group bound to the imine nitrogen (a phenyl in 3b or a ferrocenyl fragment in 3c ); the differences observed in their 195 Pt NMR spectra (δ = −3716 ppm for 3b 18b and δ = −3488 for 3c ) can be ascribed to different donor abilities of the (C,N,S) - terdentate group.…”

Experimental and Theoretical Studies of the Factors Affecting the Cycloplatination of the Chiral Ferrocenylaldimine (SC)-[(η5-C5H5)Fe{(η5-C5H4)–C(H)=N–CH(Me)(C6H5)}]

“…31 P{ 1 H}-NMR data for 7b (δ = 19.1 ( 1 JPt−P = 3801 Hz)), 8b (δ = 15.9 ( 1 JPt−P= 4191 Hz)) and 9b (δ = 15.7 ( 1 JPt−P = 4202 Hz)) are similar to those reported for related platinacycles with "(C Ph or C Fc , N,P,Cl)" cores and a trans-arrangement of the PPh3 ligand and the imine nitrogen in good agreement with the transphobia effect [61]. 195 Pt NMR spectra of compounds 7b-9b showed a doublet due to coupling with the 31 P-nucleus since it is well-known that an upfield shift in 195 Pt NMR is related to a strong donor interaction [62,63], Thus, differences detected in the 195 Pt chemical shifts of 7b and those of 8b and 9b can be taken as a measure of the different donor abilities of imine 1 adopting the (C Ph ,N) − or the (C Fc ,N) − binding mode.…”

Addition of dimethyl phosphite to imines bearing the L‐methionine moiety and its surprisingly poor chiral assistance

“…Imines 2a–d 8–11 have been prepared using a previously published method 7 by simple mixing of an aldehyde 1a–d with methionine methyl ester hydrochloride in dichloromethane in the presence of triethylamine. They were isolated and used for further conversions without previous purification (Scheme ).…”