کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1326837 977447 2007 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Preparation and characterization of d6 tungsten compounds with amino acid derivatized diimine ligands and preparation of dipeptide derivatives using peptide coupling agents
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Preparation and characterization of d6 tungsten compounds with amino acid derivatized diimine ligands and preparation of dipeptide derivatives using peptide coupling agents
چکیده انگلیسی

Attempts to prepare dipeptide compounds from organometallic N-substituted amino acids are reported. Condensation of pyridine-2-carboxaldehyde, α-amino acids (H-l-Ala-OH or H-l-Asp-OH) and W(CO)4(pip)2 leads to formation of W(CO)4(pyca-Et) (1) (pyca refers to the α-diimine fragment, C5H4NCHN) following decarboxylation of one or two equivalents of CO2. This decarboxylation does not occur for β-alanine or GABA (γ-aminobutyric acid). Coupling of [Hpip][W(CO)4(pyca-β-Ala-O)] (2) or [Hpip][W(CO)4(pyca-GABA-O)] (3) to amino acid esters, H-l-Ala-OEt, or H-l-Val-OMe, using the standard 1,3-dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBt) procedure produced four new dipeptide compounds, 4–7. The reactions proceed in good yield and compounds were characterized spectroscopically. The dipeptide complex, W(CO)4(pyca-Ala-Ala-OMe) (8), was prepared by reaction of W(CO)4(pip)2 with H-l-Ala-l-Ala-OMe and pyridine-2-carboxaldehyde. In addition the molecular structure of W(CO)4(pyca-β-Ala-Val-OMe) (5) is reported.

Condensation of pyridine-2-carboxaldehyde and α-amino acids in the presence of W(CO)4(pip)2 causes decarboxylation. Decarboxylation does not occur for β-alanine or GABA. Preparation of dipeptide compounds by coupling [Hpip][W(CO)4(pyca-(CH2)n-CO2)], n = 2 or 3, with amino acid esters is reported along with the molecular structure of W(CO)4(pyca-β-Ala-Val-OMe).Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Organometallic Chemistry - Volume 692, Issue 6, 15 February 2007, Pages 1226–1233
نویسندگان
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