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Yergeshbayeva S, Hrudka JJ, Jo M, Gakiya-Teruya M, Meisel MW, Shatruk M. Abrupt Spin Transition in a Heteroleptic Fe(II) Complex with Pendant Naphthalene Functionality. Inorg Chem 2022; 61:11349-11358. [PMID: 35816625 DOI: 10.1021/acs.inorgchem.2c01490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A heteroleptic spin-crossover (SCO) complex, [Fe(tpma)(xnap-bim)](ClO4)2 (1; tpma = tris(2-pyridylmethyl)amine, xnap-bim = 8,15-dihydrodiimidazo[1,2-a:2',1'-c]naphtho[2,3-f][1,4]diazocine), has been obtained by reacting a Fe(II) precursor salt with tetradentate tpma and bidentate xnap-bim ligands. Depending on crystallization conditions, two different solvates have been obtained, 1·2.25py·0.5H2O and 1·py. The former readily loses the interstitial solvent to produce either a powder sample of 1 upon filtration or crystals of 1 if the solvent loss is slowed by placing the crystals of 1·2.25py·0.5H2O in diethyl ether. In contrast, 1·py exhibits higher stability toward solvent loss. The crystal packing of both solvates and of the solvent-free structure features double columns of [Fe(tpma)(xnap-bim)]2+ cations formed by efficient π-π interactions between the pyridyl groups of tpma ligands, as well as by stacks supported by π-π interactions between interdigitated naphthalene fragments of xnap-bim ligands. While both solvates show a gradual SCO between the high-spin (HS) and low-spin (LS) states of the Fe(II) ion, solvent-free complex 1 exhibits an abrupt spin transition centered at 127 K, with a narrow 2 K thermal hysteresis. Complex 1 also shows a light-induced excited spin state trapping effect, manifested as LS → HS conversion upon irradiation with white light at 5 K. The metastable HS state relaxes to the ground LS state when heated above 65 K.
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Affiliation(s)
- Sandugash Yergeshbayeva
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Jeremy J Hrudka
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Minyoung Jo
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Miguel Gakiya-Teruya
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
| | - Mark W Meisel
- Department of Physics, University of Florida, Gainesville, Florida 32611-8440, United States.,National High Magnetic Field Laboratory, Gainesville, Florida 32611-8440, United States
| | - Michael Shatruk
- Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States
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Das E, Basak S, Anoop A, Chand S, Basak A. How To Achieve High Regioselectivity in Barrier-less Nucleophilic Addition to p-Benzynes Generated via Bergman Cyclization of Unsymmetrical Cyclic Azaenediyne? J Org Chem 2019; 84:2911-2921. [DOI: 10.1021/acs.joc.9b00060] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Eshani Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
| | - Shyam Basak
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
| | - Anakuthil Anoop
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
| | - Santanu Chand
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
| | - Amit Basak
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721 302, India
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Electronically Rich N-Substituted Tetrahydroisoquinoline 3-Carboxylic Acid Esters: Concise Synthesis and Conformational Studies. Tetrahedron 2012; 68:2027-2040. [PMID: 22665943 DOI: 10.1016/j.tet.2012.01.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Recent work in our laboratory has shown that the highly substituted, electronically rich 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (THIQ3CA) scaffold is a key building block for a novel class of promising anticoagulants (Al-Horani et al. J. Med. Chem.2011, 54, 6125-6138). The synthesis of THIQ3CA analogs, especially containing specific, electronically rich substituents, has been a challenge and essentially no efficient methods have been reported in the literature. We describe three complementary, glycine donor-based strategies for high yielding synthesis of highly substituted, electronically rich THIQ3CA esters. Three glycine donors studied herein include hydantoin 1, (±)-Boc-α-phosphonoglycine trimethyl ester 2 and (±)-Z-α-phosphonoglycine trimethyl ester 3. Although the synthesis of THIQ3CA analogs could be achieved using either of the three, an optimal, high yielding approach for the desired THIQ3CA esters was best achieved using 3 in three mild, efficient steps. Using this approach, a focused library of advanced N-arylacyl, N-arylalkyl, and bis-THIQ3CA analogs was synthesized. Variable temperature and solvent-dependent NMR chemical shift studies indicated the presence of two major conformational rotamers in 3:1 proportion for N-arylacyl-THIQ3CA analogs, which were separated by a high kinetic barrier of ~17 kcal/mol. In contrast, N-arylalkyl and bis-THIQ3CA variants displayed no rotamerism, which implicates restricted rotation around the amide bond as the origin for high-barrier conformational interconversion. This phenomenon is of major significance because structure-based drug design typically utilizes only one conformation. Overall, the work presents fundamental studies on the synthesis and conformational properties of highly substituted, electronically rich THIQ3CA analogs.
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Kotha S, Misra S, Gopal Krishna N, Devunuri N, Hopf H, Keecherikunnel A. Diversity-Oriented Approach to 1,2,3,4-Tetrahydroisoquinoline-3-carboxylic Acid (Tic) Derivatives Using Diethyl Acetamidomalonate as a Glycine Equivalent: Further Expansion by Suzuki–Miyaura Cross-Coupling Reaction. HETEROCYCLES 2010. [DOI: 10.3987/com-09-s(s)103] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Pratap R, Raghunandan R, Maulik P, Ram VJ. An unusual synthesis of tetrahydrobenzo[f]isoquinolines. Tetrahedron Lett 2007. [DOI: 10.1016/j.tetlet.2007.09.059] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Al-Rasbi NK, Adams H, Harding LP, Ward MD. Coordination Behaviour of Bis-Terdentate N-Donor Ligands: Double- and Single-Stranded Helicates, Mesocates, and Cyclic Oligomers. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700715] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Wang S, Dong Y, Wang X, Hu X, Liu JO, Hu Y. 3-Aryl β-carbolin-1-ones as a new class of potent inhibitors of tumor cell proliferation: synthesis and biological evaluation. Org Biomol Chem 2005; 3:911-6. [PMID: 15731878 DOI: 10.1039/b412921k] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A novel three-step synthesis of 3-aryl beta-carbolin-1-ones from non-indole starting materials has been developed. The two nitrogen atoms in beta-carbolin-1-one were introduced efficiently by Michael addition of ethyl acetamidocyanoacetate to chalcone. The desired pyridone and indole rings were assembled by an intramolecular ketone-nitrile annulation mediated by aqueous HCl-HOAc and a Cu(I)-catalyzed intramolecular N-arylation of the amide, respectively. The target compounds were found to possess significant activity against tumor cell proliferation.
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Affiliation(s)
- Shaozhong Wang
- Department of Chemistry, Tsinghua University, Beijing, 100084, P R China
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Misra L, Wagner H. Alkaloidal constituents of Mucuna pruriens seeds. PHYTOCHEMISTRY 2004; 65:2565-2567. [PMID: 15451318 DOI: 10.1016/j.phytochem.2004.08.045] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2004] [Revised: 08/10/2004] [Indexed: 05/24/2023]
Abstract
The seeds of Mucuna pruriens (L.) DC. after chemical analysis afforded four tetrahydroisoquinoline alkaloids which have been isolated for the first time from M. pruriens. Out of them, two are new whose structures have been elucidated by spectroscopic methods.
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Affiliation(s)
- Laxminarain Misra
- Phytochemistry Division, Central Institute of Medicinal and Aromatic Plants, PO--CIMAP, Lucknow 226 015, India.
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Wang S, Sun J, Yu G, Hu X, Liu JO, Hu Y. CuI catalyzed N-arylation of amide as a key step for the preparation of 3-aryl β-carbolin-1-ones. Org Biomol Chem 2004; 2:1573-4. [PMID: 15162205 DOI: 10.1039/b406046f] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
An expedient synthetic route for 3-aryl beta-carbolin-1-ones was developed starting from ethyl acetamidocyanoacetate and chalcone derivatives. The five- and six-membered nitrogen-containing rings in the beta-carbolin-1-ones were elaborated efficiently by an intramolecular ketone-nitrile annulation and an intramolecular N-arylation of amide respectively.
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Affiliation(s)
- Shaozhong Wang
- Department of Chemistry, Nanjing University, Nanjing 210093, PR China
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Gibson SE, Guillo N, Jones JO, Buck IM, Kalindjian SB, Roberts S, Tozer MJ. CCK(2) receptor antagonists containing the conformationally constrained phenylalanine derivatives, including the new amino acid Xic. Eur J Med Chem 2002; 37:379-89. [PMID: 12008052 DOI: 10.1016/s0223-5234(02)01351-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The conformationally constrained analogues of phenylalanine, tetrahydroisoquinoline-3-carboxylic acid (Tic), Sic, Hic and Nic, and the new amino acid Xic have been incorporated into a potent and highly selective cholecystokinin-2 (CCK(2)) receptor antagonist (2) in place of the phenylalanine residue, producing compounds 15a-e. High selectivities for CCK(2) over CCK(1) were observed for compounds 15a-e. The in vitro profile of the analogue containing the Nic residue (15d) was identical to that of compound 2, whereas the alternative conformational constraints resulted in a significant loss of affinity. The apparent advantage of Nic in the context of these CCK(2) ligands was subsequently demonstrated to be statistically significant.
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Affiliation(s)
- Susan E Gibson
- Department of Chemistry, King's College London, Strand, UK
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Paul RL, Bell ZR, Jeffery JC, McCleverty JA, Ward MD. Anion-templated self-assembly of tetrahedral cage complexes of cobalt(II) with bridging ligands containing two bidentate pyrazolyl-pyridine binding sites. Proc Natl Acad Sci U S A 2002; 99:4883-8. [PMID: 11929962 PMCID: PMC122688 DOI: 10.1073/pnas.052575199] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2001] [Indexed: 11/18/2022] Open
Abstract
The bridging ligands L(1) and L(2) contain two N,N-bidentate pyrazolyl-pyridine units linked to a central aromatic spacer unit (1,2-phenyl or 2,3-naphthyl, respectively). Reaction with Ni(II) salts and treatment with the anions tetrafluoroborate or perchlorate result in formation of dinuclear complexes having a 2:3 metal:ligand ratio, with one bridging and two terminal tetradentate ligands. In contrast, reaction of L(1) and L(2) with Co(II) salts, followed by treatment with tetrafluoroborate or perchlorate, results in assembly of cage complexes having a 4:6 metal:ligand ratio; these complexes have a metal ion at each corner of an approximate tetrahedron, and a bis-bidentate bridging ligand spanning each edge. The central cavity is occupied by a tetrahedral counterion that forms multiple hydrogen-bonding interactions with the methylene protons of the bridging ligands. The anionic guest fits tightly into the central cavity of the cage to which it is ideally complementary in terms of shape, size, and charge. Solution NMR experiments show that the central anion acts as a template for cage formation, with a mixture of Co(II) and the appropriate bridging ligand alone giving no assembly into a cage until the tetrahedral anion is added, at which point cage assembly is fast and quantitative. The difference between the structures of the complexes with Ni(II) and Co(II) illustrate how the uncoordinated anions can exert a profound influence on the course of the assembly process.
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Affiliation(s)
- Rowena L Paul
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, United Kingdom
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Synthesis of 6- or 7-substituted 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acids. Int J Pept Res Ther 1999. [DOI: 10.1007/bf02443634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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INCORPORATION OF CONFORMATIONALLY CONSTRAINED PHENYLALANINE DERIVATIVES TIC, SIC, HIC AND NIC INTO A CHOLECYSTOKININ-B/GASTRIN RECEPTOR ANTAGONIST. Bioorg Med Chem Lett 1997. [DOI: 10.1016/s0960-894x(97)00211-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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