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Bruzgulienė J, Račkauskienė G, Bieliauskas A, Milišiūnaitė V, Dagilienė M, Matulevičiūtė G, Martynaitis V, Krikštolaitytė S, Sløk FA, Šačkus A. Regioselective synthesis of methyl 5-( N-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates as new amino acid-like building blocks. Beilstein J Org Chem 2022; 18:102-109. [PMID: 35096179 PMCID: PMC8767561 DOI: 10.3762/bjoc.18.11] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/29/2021] [Indexed: 12/23/2022] Open
Abstract
A convenient and efficient synthesis of novel achiral and chiral heterocyclic amino acid-like building blocks was developed. Regioisomeric methyl 5-(N-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates were prepared by the reaction of β-enamino ketoesters (including azetidine, pyrrolidine or piperidine enamines) with hydroxylamine hydrochloride. Unambiguous structural assignments were based on chiral HPLC analysis, 1H, 13C, and 15N NMR spectroscopy, HRMS, and single-crystal X-ray diffraction data.
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Affiliation(s)
- Jolita Bruzgulienė
- Institute of Synthetic Chemistry, Kaunas University of Technology, K. Baršausko g. 59, Kaunas LT-51423, Lithuania
- Department of Organic Chemistry, Kaunas University of Technology, Radvilėnų pl. 19, Kaunas LT-50254, Lithuania
| | - Greta Račkauskienė
- Institute of Synthetic Chemistry, Kaunas University of Technology, K. Baršausko g. 59, Kaunas LT-51423, Lithuania
| | - Aurimas Bieliauskas
- Institute of Synthetic Chemistry, Kaunas University of Technology, K. Baršausko g. 59, Kaunas LT-51423, Lithuania
| | - Vaida Milišiūnaitė
- Institute of Synthetic Chemistry, Kaunas University of Technology, K. Baršausko g. 59, Kaunas LT-51423, Lithuania
| | - Miglė Dagilienė
- Institute of Synthetic Chemistry, Kaunas University of Technology, K. Baršausko g. 59, Kaunas LT-51423, Lithuania
| | - Gita Matulevičiūtė
- Institute of Synthetic Chemistry, Kaunas University of Technology, K. Baršausko g. 59, Kaunas LT-51423, Lithuania
| | - Vytas Martynaitis
- Department of Organic Chemistry, Kaunas University of Technology, Radvilėnų pl. 19, Kaunas LT-50254, Lithuania
| | - Sonata Krikštolaitytė
- Department of Organic Chemistry, Kaunas University of Technology, Radvilėnų pl. 19, Kaunas LT-50254, Lithuania
| | - Frank A Sløk
- Vipergen ApS, Gammel Kongevej 23A, DK-1610 Copenhagen V, Denmark
| | - Algirdas Šačkus
- Institute of Synthetic Chemistry, Kaunas University of Technology, K. Baršausko g. 59, Kaunas LT-51423, Lithuania
- Department of Organic Chemistry, Kaunas University of Technology, Radvilėnų pl. 19, Kaunas LT-50254, Lithuania
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Kara YS, Yalduz S. Substituent effect study on the experimental 13C NMR chemical shifts of 3-(substituted phenyl)-3a,4,8,8a-tetrahydro-1,3-dioxepino[5,6-d] [1,2] isoxazoles. J Mol Struct 2019. [DOI: 10.1016/j.molstruc.2019.04.121] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Vitale P, Scilimati A. Recent Developments in the Chemistry of 3-Arylisoxazoles and 3-Aryl-2-isoxazolines. ADVANCES IN HETEROCYCLIC CHEMISTRY 2017. [DOI: 10.1016/bs.aihch.2016.10.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Kara YS. Substituent effect study on experimental ¹³C NMR chemical shifts of (3-(substituted phenyl)-cis-4,5-dihydroisoxazole-4,5-diyl)bis(methylene)diacetate derivatives. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 151:723-730. [PMID: 26172459 DOI: 10.1016/j.saa.2015.07.032] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 06/01/2015] [Accepted: 07/06/2015] [Indexed: 06/04/2023]
Abstract
Eleven novel (3-(substituted phenyl)-cis-4,5-dihydroisoxazole-4,5-diyl)bis(methylene) diacetate derivatives were synthesized in the present study. These dihydroisoxazole derivatives were characterized by IR, (1)H NMR, (13)C NMR and elemental analyses. Their (13)C NMR spectra were measured in Deuterochloroform (CDCl3). The correlation analysis for the substituent-induced chemical shift (SCS) with Hammett substituent constant (σ), inductive substituent constant (σI), different of resonance substituent constants (σR, σR(o)) and Swain-Lupton substituent parameters (F, R) were performed using SSP (single substituent parameter), and DSP (dual substituent parameter) methods, as well as single and multiple regression analysis. From the result of regression analysis, the effect of substituent on the (13)C NMR chemical shifts was explained.
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Affiliation(s)
- Yesim S Kara
- Kocaeli University, Science and Art Faculty, Department of Chemistry, Umuttepe Campus, 41380 Kocaeli, Turkey.
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Cerioni G, Maccioni E, Cardia MC, Vigo S, Mocci F. Characterization of 2,5-diaryl-1,3,4-oxadiazolines by multinuclear magnetic resonance and density functional theory calculations. Investigation on a case of very remote Hammett correlation. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2009; 47:727-733. [PMID: 19479946 DOI: 10.1002/mrc.2453] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Two series of 2,5-diaryl-1,3,4-oxadiazolines have been studied by multinuclear magnetic resonance and density functional theory calculations. A full NMR spectroscopic characterization has been performed and excellent remote Hammett correlations (sigma(p) or sigma(p)+) have been found for para substitution in the two aryl rings through at least 11 bonds, notwithstanding the presence in the path of atoms that should act as insulators and a lack of correlation for some of the intermediate atoms. The computational investigation on the electronic delocalization, performed with the ACID (anisotropy of the induced current density) method, reveals indeed that electrons are delocalized in almost the entire molecule despite the presence of the insulators.
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Affiliation(s)
- Giovanni Cerioni
- Dipartimento di Scienze Chimiche, Università di Cagliari, Complesso Universitario, S.S. 554, Bivio per Sestu, I-09042 Monserrato (CA), Italy.
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Markgraf JH, Hong L, Richardson DP, Schofield MH. Substituent effects on (15)N and (13)C NMR chemical shifts of 5-phenyl-1,3,4-oxathiazol-2-ones: a theoretical and spectroscopic study. MAGNETIC RESONANCE IN CHEMISTRY : MRC 2007; 45:985-8. [PMID: 17894426 DOI: 10.1002/mrc.2082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
The synthesis and assignment of (15)N and (13)C NMR signals of the 1,3,4-oxathiazol-2-one ring in a series of para-substituted 5-phenyl derivatives are reported. DFT calculations of (15)N and (13)C chemical shifts correspond closely to observed values. Substituent effects are interpreted in terms of the Hammett correlation and calculated bond orders.
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Affiliation(s)
- J Hodge Markgraf
- Department of Chemistry, Williams College, Williamstown, MA 01267-2692, USA
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