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Travagin F, Lattuada L, Giovenzana GB. AAZTA: The rise of mesocyclic chelating agents for metal coordination in medicine. Coord Chem Rev 2021. [DOI: 10.1016/j.ccr.2021.213908] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Zhu C, Han MY, Liang XX, Guan B, Li P, Wang L. Hydrogen-Bond-Assisted Sequential Reaction of Silyl Glyoxylates: Stereoselective Synthesis of Silyl Enol Ethers. Org Lett 2021; 23:54-59. [PMID: 33320686 DOI: 10.1021/acs.orglett.0c03683] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A novel hydrogen-bond-assisted sequential reaction of silyl glyoxylates is described. This method provides an efficient strategy for the synthesis of silyl enol ethers with high selectivity. In these transformations, hydrogen bonds from 2-nitroethanol and its derivatives are critical to the stereochemical outcome. Both E- and Z-isomers are achieved via Henry reaction/Brook rearrangement/elimination and Henry reaction/Brook rearrangement/retro-Henry reaction/elimination processes, respectively (up to 99:1 Z-selectivity, and 9.2:1 E-selectivity).
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Affiliation(s)
- Chen Zhu
- Department of Chemistry, Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, Huaibei Normal University, Huaibei, Anhui 235000, P.R. China
| | - Man-Yi Han
- Department of Chemistry, Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, Huaibei Normal University, Huaibei, Anhui 235000, P.R. China
| | - Xiu-Xia Liang
- Department of Chemistry, Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, Huaibei Normal University, Huaibei, Anhui 235000, P.R. China
| | - Bin Guan
- Department of Chemistry, Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, Huaibei Normal University, Huaibei, Anhui 235000, P.R. China
| | - Pinhua Li
- Department of Chemistry, Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, Huaibei Normal University, Huaibei, Anhui 235000, P.R. China.,State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai 200032, P.R. China
| | - Lei Wang
- Department of Chemistry, Key Laboratory of Green and Precise Synthetic Chemistry, Ministry of Education, Huaibei Normal University, Huaibei, Anhui 235000, P.R. China.,State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai 200032, P.R. China.,Advanced Research Institute and Department of Chemistry, Taizhou University, Taizhou, Zhejiang 318000, P.R. China
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Kock FVC, Forgács A, Guidolin N, Stefania R, Vágner A, Gianolio E, Aime S, Baranyai Z. [Gd(AAZTA)] - Derivatives with n-Alkyl Acid Side Chains Show Improved Properties for Their Application as MRI Contrast Agents*. Chemistry 2020; 27:1849-1859. [PMID: 33184913 DOI: 10.1002/chem.202004479] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 11/03/2020] [Indexed: 12/25/2022]
Abstract
Herein, the synthesis and an extensive characterization of two novel Gd(AAZTA) (AAZTA=6-amino-6-methylperhydro-1,4-diazepine tetra acetic acid) derivatives functionalized with short (C2 and C4 ) n-alkyl acid functions are reported. The carboxylate functionality is the site for further conjugations for the design of more specific contrast agents (CAs). Interestingly, it has been found that the synthesized complexes display enhanced properties for use as MRI contrast agents on their own. The stability constants determined by using potentiometric titration and UV/Vis spectrophotometry were slightly higher than the one reported for the parent Gd(AAZTA) complex. This observation might be accounted for by the larger sigma-electron donation of the acyl substituents with respect to the one provided by the methyl group in the parent complex. As far as concerns the kinetic stability, transmetallation experiments with endogenous ions (e.g. Cu2+ ) implied that the Gd3+ ions present in these Gd(AAZTA) derivatives show somewhat smaller susceptibility to chemical exchange towards these ions at 25 °C, close to the physiological condition. The 1 H NMR spectra of the complexes with EuIII and YbIII displayed a set of signals consistent with half the number of methylene protons present on each ligand. The number of resonances was invariant over a large range of temperatures, suggesting the occurrence of a fast interconversion between structural isomers. The relaxivity values (298 K, 20 MHz) were consistent with q=2 being equal to 8.8 mm-1 s-1 for the C2 derivative and 9.4 mm-1 s-1 for the C4 one, that is, sensibly larger than the one reported for Gd(AAZTA) (7.1 mm-1 s-1 ). Variable-temperature (VT)-T2 17 O NMR measurements showed, for both complexes, the presence of two populations of coordinated water molecules, one in fast and one in slow exchange with the bulk water. As the high-resolution 1 H NMR spectra of the analogs with EuIII and YbIII did not show the occurrence of distinct isomers (as frequently observed in other macrocyclic lanthanide(III)-containing complexes), we surmised the presence of two fast-interconverting isomers in solution. The analysis of the 17 O NMR VT-T2 profiles versus temperature allowed their relative molar fraction to be established as 35 % for the isomer with the fast exchanging water and 65 % for the isomer with the water molecules in slower exchange. Finally, 1 H NMRD profiles over an extended range of applied magnetic field strengths have been satisfactory fitted on the basis of the occurrence of the two interconverting species.
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Affiliation(s)
- Flávio Vinicius Crizóstomo Kock
- São Carlos Institute of Chemistry, University of São Paulo, Avenida Trabalhador São Carlense 400, 13566-590, São Paulo, Brazil.,Department of Molecular Biotechnologies and Health Science, University of Turin, Via Nizza 52, 10125, Turin, Italy
| | - Attila Forgács
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, 4010, Debrecen, Hungary.,MTA-DE Redox and Homogeneous Catalytic Reaction Mechanisms, Research Group, Egyetem tér 1, Debrecen, 4032, Hungary
| | - Nicol Guidolin
- Bracco Imaging SpA, Bracco Research Center, Via Ribes 5, 10010, Colleretto Giacosa (TO), Italy
| | - Rachele Stefania
- Department of Molecular Biotechnologies and Health Science, University of Turin, Via Nizza 52, 10125, Turin, Italy
| | - Adrienn Vágner
- Department of Inorganic and Analytical Chemistry, University of Debrecen, Egyetem tér 1, 4010, Debrecen, Hungary
| | - Eliana Gianolio
- Department of Molecular Biotechnologies and Health Science, University of Turin, Via Nizza 52, 10125, Turin, Italy
| | - Silvio Aime
- Department of Molecular Biotechnologies and Health Science, University of Turin, Via Nizza 52, 10125, Turin, Italy
| | - Zsolt Baranyai
- Bracco Imaging SpA, Bracco Research Center, Via Ribes 5, 10010, Colleretto Giacosa (TO), Italy
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Wang SM, Zhao C, Zhang X, Qin HL. Clickable coupling of carboxylic acids and amines at room temperature mediated by SO 2F 2: a significant breakthrough for the construction of amides and peptide linkages. Org Biomol Chem 2020; 17:4087-4101. [PMID: 30957817 DOI: 10.1039/c9ob00699k] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The construction of amide bonds and peptide linkages is one of the most fundamental transformations in all life processes and organic synthesis. The synthesis of structurally ubiquitous amide motifs is essential in the assembly of numerous important molecules such as peptides, proteins, alkaloids, pharmaceutical agents, polymers, ligands and agrochemicals. A method of SO2F2-mediated direct clickable coupling of carboxylic acids with amines was developed for the synthesis of a broad scope of amides in a simple, mild, highly efficient, robust and practical manner (>110 examples, >90% yields in most cases). The direct click reactions of acids and amines on a gram scale are also demonstrated using an extremely easy work-up and purification process of washing with 1 M aqueous HCl to provide the desired amides in greater than 99% purity and excellent yields.
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Affiliation(s)
- Shi-Meng Wang
- State Key Laboratory of Silicate Materials for Architectures; and School of Chemistry, Chemical Engineering and Life Science, Wuhan University of Technology, 205 Luoshi Road, Wuhan, 430070, P. R. China.
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Targeted synthesis and biological activity of polypharmacophoric agents for the treatment of neurodegenerative diseases. Russ Chem Bull 2018. [DOI: 10.1007/s11172-017-1953-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Hsieh YY, Raja A, Hong BC, Kotame P, Chang WC, Lee GH. Organocatalytic Enantioselective Michael–Acetalization–Henry Reaction Cascade of 2-Hydroxynitrostyrene and 5-Oxohexanal for the Entry to the Hexahydro-6H-benzo[c]chromenones with Four Consecutive Stereogenic Centers and an Approach to Aflatoxin Analogues. J Org Chem 2017; 82:12840-12848. [DOI: 10.1021/acs.joc.7b02178] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Yu-You Hsieh
- Department
of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 621, Taiwan, R.O.C
| | - Arun Raja
- Department
of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 621, Taiwan, R.O.C
| | - Bor-Cherng Hong
- Department
of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 621, Taiwan, R.O.C
| | - Prakash Kotame
- Department
of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 621, Taiwan, R.O.C
| | - Wan-Chen Chang
- Department
of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 621, Taiwan, R.O.C
| | - Gene-Hsiang Lee
- Instrumentation
Center, National Taiwan University, Taipei 106, Taiwan, R.O.C
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Methanol facilitated synthesis of 7-methoxy-2-thioxo-2,3-dihydro-1H-1,3-diazepin-4(7H)-ones from nitroallylic acetates and thiourea. Tetrahedron 2014. [DOI: 10.1016/j.tet.2014.08.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Affiliation(s)
- Adam Noble
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
| | - James C. Anderson
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
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