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Shilov RA, Podkorytov IS, Kisel KS, Galenko EE, Karpitskaya DO, Rodionov IA, Shakirova JR, Tunik SP. DPPM-Bridged Binuclear Pt(II) Pincer Complexes: Chemistry, Structure, and Photophysics in Solution Revisited. Inorg Chem 2024; 63:11194-11208. [PMID: 38836300 DOI: 10.1021/acs.inorgchem.4c00984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
A series of luminescent binuclear ([dppm{Pt(NNC)}2]2+) and mononuclear ([PPh3Pt(NNC)]+) complexes containing pincer ligands were synthesized and characterized. Photophysical characteristics of both types of complexes were studied in dichloromethane solution. In the solid phase, the binuclear compounds adopt a syn configuration where the {Pt(NNC)} fragments are held together due to intramolecular Pt-Pt bonding and π-stacking of the pincer ligand aromatic systems. Analysis of the complexes' molecular structure in solution by multinuclear NMR spectroscopy showed that the stacked intramolecular configuration is retained in fluid media, which is in complete agreement with a considerable red shift of the emission wavelength due to formation of the intramolecular Pt-Pt bond, leading to the transformation of an emissive excited state to 3MMLCT. It was also found that triethylamine quenches the emission of both types of complexes; the mechanism of quenching is a combination of dynamic and static channels of excited-state deactivation. In the case of binuclear complexes, deprotonation of the dppm methylene bridge by triethylamine also contributes to the chromophore quenching. To explain the observed chemistry of binuclear complex interactions with Et3N, a chemical equilibrium scheme was suggested, which was confirmed by quantitative monitoring of the 31P signal variations as a function of triethylamine concentration.
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Affiliation(s)
- Roman A Shilov
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint Petersburg, Russia
| | - Ivan S Podkorytov
- Biomolecular NMR Laboratory, St. Petersburg State University, 7-9 Universitetskaya Emb., 199034 Saint Petersburg, Russia
| | - Kristina S Kisel
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint Petersburg, Russia
| | - Ekaterina E Galenko
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint Petersburg, Russia
| | - Daria O Karpitskaya
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint Petersburg, Russia
| | - Ivan A Rodionov
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint Petersburg, Russia
| | - Julia R Shakirova
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint Petersburg, Russia
| | - Sergey P Tunik
- Institute of Chemistry, St. Petersburg State University, Universitetskii av., 26, 198504 Saint Petersburg, Russia
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Galenko EE, Kryukova MA, Novikov MS, Khlebnikov AF. An Isoxazole Strategy for the Synthesis of Fully Substituted Nicotinates. J Org Chem 2021; 86:6888-6896. [PMID: 33847124 DOI: 10.1021/acs.joc.1c00286] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
A four-step quasi one-pot procedure for the preparation of fully substituted nicotinates from ketone enamines and 4-methylideneisoxazol-5-ones has been developed. The reaction sequence involves (1) reaction of 4-methylideneisoxazol-5-ones with ketone enamines with the formation of isoxazole-5-ols, (2) their O-methylation with diazomethane, (3) hydrogenative cleavage of the O-N bond in 5-methoxyisoxazoles under action of Mo(CO)6/H2O and simultaneous isomerization and condensation of the formed enamines, with the formation of dihydropyridines, and (4) aromatization of the latter.
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Affiliation(s)
- Ekaterina E Galenko
- Saint Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya Naberezhnaya, St. Petersburg 199034, Russia
| | - Mariya A Kryukova
- Saint Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya Naberezhnaya, St. Petersburg 199034, Russia
| | - Mikhail S Novikov
- Saint Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya Naberezhnaya, St. Petersburg 199034, Russia
| | - Alexander F Khlebnikov
- Saint Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya Naberezhnaya, St. Petersburg 199034, Russia
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Serebryannikova AV, Galenko EE, Novikov MS, Khlebnikov AF. Product selectivity of thermal Buchner reaction of methyl 2-(3-arylisoxazol-5-yl)-2-diazoacetates with benzene, naphthalene and mesitylene, and ring-opening/closing reaction of products. Tetrahedron 2021. [DOI: 10.1016/j.tet.2021.132153] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Zanakhov TO, Galenko EE, Kryukova MA, Novikov MS, Khlebnikov AA. Isomerization of 5-(2 H-Azirin-2-yl)oxazoles: An Atom-Economic Approach to 4 H-Pyrrolo[2,3- d]oxazoles. Molecules 2021; 26:molecules26071881. [PMID: 33810476 PMCID: PMC8036974 DOI: 10.3390/molecules26071881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/19/2021] [Accepted: 03/23/2021] [Indexed: 11/16/2022] Open
Abstract
An atom economical method for the preparation of variously substituted 4H-pyrrolo[2,3-d]oxazoles was developed on the basis of thermal isomerization of 5-(2H-azirin-2-yl)oxazoles. The latter were prepared by Rh2(oct)4 catalyzed reaction of 2-(3-aryl/heteroaryl)-2-diazoacetyl-2H-azirines with a set of substituted acetonitriles, benzonitriles, acrylonitrile and fumaronitrile. According to DFT calculations the transformation of 5-(2H-azirin-2-yl)oxazole to 4H-pyrrolo[2,3-d]oxazole occurs through the nitrenoid-like transition state to give a 3aH-pyrrolo[2,3-d]oxazole intermediate, followed by 1,5-H-shift.
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Agafonova AV, Funt LD, Novikov MS, Khlebnikov AF. An isoxazole strategy for the synthesis of alkyl 5-amino-4-cyano-1 H-pyrrole-2-carboxylates - versatile building blocks for assembling pyrrolo-fused heterocycles. Org Biomol Chem 2021; 19:1976-1984. [PMID: 33566047 DOI: 10.1039/d1ob00053e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A full atom-economical domino method has been developed for the preparation of alkyl 5-amino-4-cyano-1H-pyrrole-2-carboxylates by transannulation of 5-alkoxyisoxazoles with malononitrile under Fe(ii) catalysis. Alkyl 5-amino-4-cyano-1H-pyrrole-2-carboxylates are excellent building blocks for various annulation reactions, leading to new derivatives of 1H-pyrrolo[1,2-a]imidazole and pyrrolo[2,3-d]pyrimidine. The DFT calculations of mechanistic details of alkyl 5-amino-4-cyano-1H-pyrrole-2-carboxylate formation are presented.
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Affiliation(s)
- Anastasiya V Agafonova
- St Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St Petersburg, 199034, Russia.
| | - Liya D Funt
- St Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St Petersburg, 199034, Russia.
| | - Mikhail S Novikov
- St Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St Petersburg, 199034, Russia.
| | - Alexander F Khlebnikov
- St Petersburg State University, Institute of Chemistry, 7/9 Universitetskaya nab., St Petersburg, 199034, Russia.
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