title: Synthesis and characterization of rhenium(V) oxo complexes with N-[N-(3-diphenylphosphinopropionyl)glycyl]cysteine methyl ester. X-ray crystal structure of (ReO[Ph(2)P(CH(2))(2)C(O)-Gly-Cys-OMe(P,N,N,S)]).
abstract: The PN(2)S chelate N-[N-(3-diphenylphosphinopropionyl)glycyl]-S-tritylcysteine methyl ester [PN(2)S(Trt)-OMe] was synthesized and reacted with ReOCl(3)(PPh(3))(2) and Ph(4)P[ReOCl(4)]. The reactions of both tritylated and detritylated ligands with Re(V)O precursors gave two diastereomers, 9a and 9b, of the ReO(PN(2)S-OMe) complex. The two isomers, produced in a 1:1 molar ratio, are stable and do not interconvert. They were separated by reverse-phase HPLC and characterized by NMR, FT-IR, and UV-visible spectroscopy and electrospray mass spectrometry. X-ray analysis established for 9a the presence in the solid of the syn isomer. Compound 9a, C(21)H(23)N(2)O(5)PSRe, crystallized from warm acetonitrile in the triclinic space group Ponemacr;, a = 9.828(2) A, b = 11.163(2) A, c = 11.641(2) A, alpha = 106.48(3) degrees, beta = 109.06(3) degrees, gamma = 102.81(3) degrees, V = 1085.7(4) A(3), Z = 2. The PN(2)S coordination set is in the equatorial plane, and the complex shows a distorted square pyramidal coordination. The anti configuration assigned to 9b is consistent with all the available physicochemical data. Follow-up of the reaction of the detritylated ligand with Ph(4)P[ReOCl(4)] in ethanol or acetonitrile indicated that the phosphorus atom of the chelate binds first to the metal and that this bond acts as the driving force for coordination.
authors.affiliation: Department of Pharmaceutical Sciences, University of Padova, 35131 Padova, Italy.
authors.forename: Roberta
authors.initials: R
authors.lastname: Visentin
authors.forename: Raffaella
authors.initials: R
authors.lastname: Rossin
authors.forename: Maria Cecilia
authors.initials: MC
authors.lastname: Giron
authors.forename: Alessandro
authors.initials: A
authors.lastname: Dolmella
authors.forename: Giuliano
authors.initials: G
authors.lastname: Bandoli
authors.forename: Ulderico
authors.initials: U
authors.lastname: Mazzi
mesh_terms: D002384:Catalysis; D002614:Chelating Agents / Q000138:chemical synthesis* / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods; D018360:Crystallography, X-Ray; D004151:Dipeptides / Q000138:chemical synthesis* / Q000737:chemistry; D005998:Glycine / Q000737:chemistry; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008968:Molecular Conformation; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000737:chemistry; D012211:Rhenium / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D002614:Chelating Agents; D004151:Dipeptides; D008024:Ligands; D009942:Organometallic Compounds; D019275:Radiopharmaceuticals; D012211:Rhenium; D005998:Glycine