Isopyrazole‐Masked Tetraketone: Tautomerism and Functionalization for Fluorescent Metal Ligands

2021 ◽  
Author(s):  
Hayato Shirakura ◽  
Yumehiro Manabe ◽  
Chika Kasai ◽  
Yuya Inaba ◽  
Makoto Tsurui ◽  
...  
Keyword(s):  
Metal Ligands

Computationally-Guided Investigation of Dual Amine/pi Lewis Acid Catalysts for Direct Additions of Aldehydes and Ketones to Unactivated Alkenes and Alkynes

2020 ◽  
Author(s):  
Eric Greve ◽  
Jacob D. Porter ◽  
Chris Dockendorff
Keyword(s):  
Lewis Acid ◽  
Density Functional ◽  
Acid Catalyst ◽  
Metal Catalyst ◽  
Catalyst Poisoning ◽  
Lewis Acid Catalysts ◽  
Metal Ligands ◽  
Aldehydes And Ketones ◽  
Lewis Acid Catalyst ◽  
Catalyst Systems

Dual amine/pi Lewis acid catalyst systems have been reported for intramolecular direct additions of aldehydes/ketones to unactivated alkynes and occasionally alkenes, but related intermolecular reactions are rare and not presently of significant synthetic utility, likely due to undesired coordination of enamine intermediates to the metal catalyst. We reasoned that bulky metal ligands and bulky amine catalysts could minimize catalyst poisoning and could facilitate certain examples of direct intermolecular additions of aldehyde/ketones to alkenes/alkynes. Density Functional Theory (DFT) calculations were performed that suggested that PyBOX-Pt(II) catalysts for alkene/alkyne activation could be combined with MacMillan’s imidazolidinone organocatalyst for aldehyde/ketone activation to facilitate desirable C-C bond formations, and certain reactions were calculated to be more exergonic than catalyst poisoning pathways. As calculated, preformed enamines generated from the MacMillan imidazolidinone did not displace ethylene from a biscationic (<i>t</i>-Bu)PyBOX-Pt<sup>2+</sup>complex, but neither were the desired C-C bond formations observed under several different conditions.

Computationally-Guided Investigation of Dual Amine/pi Lewis Acid Catalysts for Direct Additions of Aldehydes and Ketones to Unactivated Alkenes and Alkynes

2020 ◽  
Author(s):  
Eric Greve ◽  
Jacob D. Porter ◽  
Chris Dockendorff
Keyword(s):  
Lewis Acid ◽  
Density Functional ◽  
Acid Catalyst ◽  
Metal Catalyst ◽  
Catalyst Poisoning ◽  
Lewis Acid Catalysts ◽  
Metal Ligands ◽  
Aldehydes And Ketones ◽  
Lewis Acid Catalyst ◽  
Catalyst Systems

Dual amine/pi Lewis acid catalyst systems have been reported for intramolecular direct additions of aldehydes/ketones to unactivated alkynes and occasionally alkenes, but related intermolecular reactions are rare and not presently of significant synthetic utility, likely due to undesired coordination of enamine intermediates to the metal catalyst. We reasoned that bulky metal ligands and bulky amine catalysts could minimize catalyst poisoning and could facilitate certain examples of direct intermolecular additions of aldehyde/ketones to alkenes/alkynes. Density Functional Theory (DFT) calculations were performed that suggested that PyBOX-Pt(II) catalysts for alkene/alkyne activation could be combined with MacMillan’s imidazolidinone organocatalyst for aldehyde/ketone activation to facilitate desirable C-C bond formations, and certain reactions were calculated to be more exergonic than catalyst poisoning pathways. As calculated, preformed enamines generated from the MacMillan imidazolidinone did not displace ethylene from a biscationic (<i>t</i>-Bu)PyBOX-Pt<sup>2+</sup>complex, but neither were the desired C-C bond formations observed under several different conditions.

Applications of supramolecular capsules derived from resorcin[4]arenes, calix[n]arenes and metallo-ligands: from biology to catalysis

RSC Advances ◽  
2015 ◽  
Vol 5 (64) ◽  
pp. 51919-51933 ◽  
Author(s):  
Chiara M. A. Gangemi ◽  
Andrea Pappalardo ◽  
Giuseppe Trusso Sfrazzetto
Keyword(s):  
Material Science ◽  
Metal Ligands ◽  
Biomedical Field

This review summarizes supramolecular capsules based on resorcin[4]arenes, calix[n]arenes and metal–ligands, having concrete applications in biomedical field, catalysis and material science.

Expression of manganese lipoxygenase in Pichia pastoris and site-directed mutagenesis of putative metal ligands

2005 ◽  
Vol 434 (1) ◽  
pp. 201-211 ◽  
Author(s):  
Mirela Cristea ◽  
Åke Engström ◽  
Chao Su ◽  
Lena Hörnsten ◽  
Ernst H. Oliw
Keyword(s):  
Pichia Pastoris ◽  
Site Directed Mutagenesis ◽  
Directed Mutagenesis ◽  
Metal Ligands

scholarly journals Synthesis, characterization, x-ray diffraction studies and biological activities of iron(III) and cobalt(II) complexes with alanine

2018 ◽  
Vol 6 (2) ◽  
pp. 132
Author(s):  
Shuaibu Musa ◽  
S O. Idris ◽  
A D. Onu
Keyword(s):  
Amino Acid ◽  
Biological Activities ◽  
Human Life ◽  
Molar Conductance ◽  
Biological Molecules ◽  
X Ray Diffraction ◽  
Monoclinic Crystal ◽  
X Ray ◽  
Metal Ligands ◽  
Elemental Analyses

The resulted complexes produced between Fe (III) and Co (II) with biological molecules like amino acids play an important role in human life. They can be used as bioactive compounds as well as in industries. Fe (III) and Co (II) complexes are synthesized with Alanine amino acid. The complexes were characterized by X-ray diffraction, magnetic suscetivility, elemental analysis (AAS), molar conductance, melting point, infrared and uv-visible spectrophotometry analyses. The elemental analyses were used to determine the chelation ratio, 1:3(metal: ligands) for iron (III) Alanine and 1:2 ratio for cobalt (II) Alanine. The molar conductivity of the complexes show that the complexes are not electrolytic in nature. The x-ray data suggest monoclinic crystal system for all the complexes with the exception of Co-alanine, which is hexagonal. The magnetic susceptivility and electronic spectra suggest the complexes are high spin with octahedral geometry.The complexes show enhance activity in comparable to the amino acid.  

Insight into the hydrogen evolution reaction of nickel dichalcogenide nanosheets: activities related to non-metal ligands

Nanoscale ◽  
2017 ◽  
Vol 9 (17) ◽  
pp. 5538-5544 ◽  
Author(s):  
Yuancai Ge ◽  
Shang-Peng Gao ◽  
Pei Dong ◽  
Robert Baines ◽  
Pulickel M. Ajayan ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Metal Ligands ◽  
Insight Into

scholarly journals Detailed Molecular and Structural Analysis of Dual Emitter IrQ(ppy)2 Complex

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1617
Author(s):  
Iulia Corina Ciobotaru ◽  
Daniel Nicolae Crisan ◽  
Primoz Šket ◽  
Constantin Claudiu Ciobotaru ◽  
Silviu Polosan
Keyword(s):  
Organometallic Compound ◽  
High Performance ◽  
Structural Model ◽  
Chemical Yield ◽  
Interatomic Distances ◽  
X Ray ◽  
Metal Ligands ◽  
Final Compound ◽  
X Ray Absorption ◽  
Detailed Molecular Analysis

The molecular structure of the 8-hydroxyquinoline–bis (2-phenylpyridyl) iridium (IrQ(ppy)2) dual emitter organometallic compound is determined based on detailed 1D and 2D nuclear magnetic resonance (NMR), to identify metal-ligands coordination, isomerization and chemical yield of the desired compound. Meanwhile, the extended X-ray absorption fine structure (EXAFS) was used to determine the interatomic distances around the iridium ion. From the NMR results, this compound IrQ(ppy)2 exhibits a trans isomerization with a distribution of coordinated N-atoms in a similar way to facial Ir(ppy)3. The EXAFS measurements confirm the structural model of the IrQ(ppy)2 compound where the oxygen atoms from the quinoline ligands induce the splitting of the next-nearest neighboring C in the second shell of the Ir3+ ions. The high-performance liquid chromatography (HPLC), as a part of the detailed molecular analysis, confirms the purity of the desired IrQ(ppy)2 organometallic compound as being more than 95%, together with the progress of the chemical reactions towards the final compound. The theoretical model of the IrQ(ppy)2, concerning the expected bond lengths, is compared with the structural model from the EXAFS and XRD measurements.

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