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We herein report the synthesis of substituted tryptophans using Ni(II) complexes of glycine and gramines. This reaction proceeds under operationally convenient and mild conditions, using inexpensive, nontoxic, and easily accessible reagents. The reactions feature high yields and virtually complete thermodynamically controlled diastereoselectivity, providing a convenient method for the synthesis of tailor-made tryptophans.
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http://dx.doi.org/10.1021/acs.joc.4c02406 | DOI Listing |
Inorg Chem
September 2025
Department of Chemistry, Panskura Banamali College, Panskura RS, Purba Medinipur, WB 721152, India.
We report the synthesis and characterization of a new Schiff base ligand (HL), derived from 2-picolylamine and 2-hydroxy-3-methoxy-5-methylbenzaldehyde. Its reaction with Ni(NO)·6HO and Ln(NO)·HO (Ln = Gd, Tb, Dy) in the presence of triethylamine affords a carbonato-bridged family of heterobimetallic NiLn complexes: [NiLn(L)(L')(μ-CO)(NO)]·MeOH·HO (). During the complexation reaction, ligand HL undergoes an oxidation, followed by C-C coupling to generate a secondary ligand (HL').
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
September 2025
Department of Chemistry, Taras Shevchenko National University of Kyiv, Volodymyrska Street 64, Kyiv, 01601, Ukraine.
The unit cell of the title compound, [Ni(CHNO)]·2CHOH, consists of a neutral complex and two methanol mol-ecules. In the complex, the two tridentate 2-[3-(benzo[][1,3]dioxol-5-yl)-1-1,2,4-triazol-5-yl]-6-(1-pyrazol-1-yl)pyridine ligands coordinate to the central Ni ion through nitro-gen atoms of the pyrazole, pyridine and triazole groups, forming a pseudo-octa-hedral coordination sphere. Neighbouring mol-ecules are linked through weak C-H(pz)⋯π(ph) inter-actions into monoperiodic chains, which are further linked through weak C-H⋯H/N/C inter-actions into diperiodic layers.
View Article and Find Full Text PDFJ Inorg Biochem
August 2025
Faculty of Chemistry, University of Wroclaw, F. Joliot - Curie 14, 50-383 Wroclaw, Poland.
This study presents the synthesis, structural characterization, and biological evaluation of three nickel(II) complexes containing bioactive ligands: two bidentate pyridyl alcohols (2-pymetH and 2-pyetH) and a mixed-ligand system with memantine and acetylacetone. Single-crystal X-ray diffraction revealed that all complexes adopt a distorted octahedral geometry with a {NiN₂O₄} coordination core, differing in ligand orientation, symmetry, and supramolecular packing. Complementary spectroscopic techniques, including FT-IR, Raman, and UV-Vis, confirmed successful ligand coordination and complex integrity.
View Article and Find Full Text PDFOrg Lett
September 2025
Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China.
Cyclization of -dibromo tetrapyrrolic Ni complex with KS, NaSe, and NaTe gave Ni 5-sulfacorrole, Ni 5-selenacorrole, and Ni 5-telluracorrole, respectively, as the first example of 5-heterocorrole. The corresponding Cu 5-heterocorroles were similarly synthesized from Cu complex , while Ni 5-oxacorrole was synthesized by reaction of with Ni(cod) and 2,2'-bipyridine and subsequent oxygen-insertion reaction of molecular oxygen, and Cu 5-oxacorrole was obtained from reaction of with Cu thiophene-2-carboxylate (CuTC) and tetrabutylammonium hydroxide. Moderate aromatic characters of the Ni 5-heterocorroles are evinced by the H NMR chemical shifts, the absorption spectra, and DFT calculations.
View Article and Find Full Text PDFDalton Trans
September 2025
University of Cologne, Faculty for Mathematics and Natural Sciences, Department of Chemistry and Biochemistry, Institute for Inorganic and Materials Chemistry, Greinstrasse 6, D-50939 Köln, Germany.
In the frame of our research aiming to develop efficient triplet-emitting materials, we are exploring the role of the second coordination sphere in enhancing the rigidity of structures and its controlling aspect over the extents of excited state distortions. We thus synthesised three N^C^N cyclometalated complexes [M(L)Cl] (M = Pt, Pd, and Ni), where the two -positions of the pyridyl moieties in 1,3-di(2-pyridyl)-benzene are benzyl substituted (Bn) forming a tight binding pocket for the metal and the Cl ancillary ligand. The molecular structures from single-crystal X-ray diffraction show a markedly distorted square planar M(II) coordination with values of around 0.
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