Reaktionen von Glycinato‐Verbindungen von Platin(II), Palladium(II) und Kupfer(II) mit Amidacetalen: Schiffbase‐Komplexe

Abstract

Eine Reihe von Schiffbase-Komplexen von Platin(II), Palladium(I1) und Kupfer(I1) 1 -4 wird aus Glycinato-Chelatkomplexen und Amidacetalen erhalten. Die Struktur der Verbindungen wird spektroskopisch, die von Cl(n-Bu,P)PtO,C -CH, -N = CHNMe, (3a) durch Rontgenstrukturanalyse bestimmt. Bei trans-Bis(glycinato)platin(II) wird mit DMF auch Reaktion an der a-Methylengruppe eines Glycinat-Liganden unter Bildung eines Serinderivats als Liganden (5) beobachtet, wobei der Bis(Schiffbase)-Komplex 2a als Zwischenprodukt isoliert werden kann. Amidacetale greifen (Glycinato)platin(II)-Komplexe primar stets an der Aminogruppe an, erst im zweiten Schritt kann die Reaktion an der a-Methylengruppe des koordinierten Schiffbase-Liganden erfolgen.A series of Schiff base complexes of platinum(II), palladium(II), and copper(I1) 1 -4 has been obtained from glycinato chelate compounds and amide acetals. The structure of the complexes has been determined by their IR and NMR spectra, that of 3a by an X ray structure analysis. With trans-bis(glycinato)platinum(II) also reaction with DMF at the a-methylene group of a glycinate ligand has been observed to give a serine derivative as ligand (5), the Schiff base complex 2a being isolated as intermediate. The first step of these reactions always is an attack of the amide acetal at the amino group; the coordinated and activated Schiff base ligands may also react at the a-rnethylene group. *) Die in Lit . 5 ) beschriebenen Umsetzungen von (n-Bu3P)Pt(Cl)(glycinat) mit Aldehyden und Alkylierungsmitteln konnten wir unter den angegebenen Bedingungen nicht mehr reproduzieren.

Metal Complexes of Biologically Important Ligands, CLXXII [1]. Metal Ions and Metal Complexes as Protective Groups of Amino Acids and Peptides – Reactions at Coordinated Amino Acids

“…The product from the ortho-metallated N,Ndimethylbenzylamine-glycinate Pd(II) complex with formaldehyde was formulated as the N-methylene Schiff base complex 29 (Scheme 6) [144]. Although the analysis for 29·H 2 O is identical with that for a serinate complex, evidence for 29 comes from the reaction of 29 with acetaldehyde which -after removal of Pd(II) by reduction with H 2 /Pd/C -afforded threonine [144].…”

“…Although the analysis for 29·H 2 O is identical with that for a serinate complex, evidence for 29 comes from the reaction of 29 with acetaldehyde which -after removal of Pd(II) by reduction with H 2 /Pd/C -afforded threonine [144]. Unexpected is the N,N -dimethylation of Cu(β -alaO) by formaldehyde [172].…”

“…Various Schiff base complexes of nickel(II), cobalt(II), palladium(II) and platinum(II) and platinum(IV) of type 21 (Scheme 5) have been prepared from glycinato chelate complexes and dimethylformamide acetal [144].…”

“…This reaction has been used commercially for the production of threonine [142]. The aldol condensation of metal-coordinated glycinate can be performed also with other metal ions, e. g. with Co(III) [141b], Ni(II) [143], Pd(II) [144], and has found much interest [145].…”

Metallkomplexe mit biologisch wichtigen Liganden, XXXIX [1]. Platin(IV)-Komplexe mit α-Aminosäure-und Peptidestern; 15N-und 195Pt-NMR-Spektren von α-Aminosäuren-Platin-Komplexen / Metal Complexes with Biologically Important Ligands, XXXIX [1]. Platinum(IV) Complexes with α-Amino Acid Esters and Peptide Esters; 13N and 195Pt NMR Spectra of Platinum Complexes with α-Amino Acids

“…4254 350 rram-PtCl 2 (L-AlaOH) 2 [25] 2304 520 rrans-PtCL(L-PheOH) 2 [26] 2294 100 m-PtCL(GlyOEt) 2 [14] 2333 400 ds-PtCl 2 (L-AlaOEt) 2 [14] 2347 430 m-PtCl 2 (L-LeuOEt) 2 [14] 2318 380 [22]). In der Literatur finden sich die 195 Pt-NMR-Daten der Komplexe [PtCl 2 (GlyO)r [23], [Pt(NH 3 ) 2 (GlyO)] + [21], (n-Bu 3 P) (Cl)Pt(GlyO) [24] sowie einer Reihe von Schiffbase-Komplexen aus Aminosäuren [24],…”