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Wang K, Li H, Yang L, Liu ZJ, Yao ZJ. Half-Sandwich Ruthenium Complexes with Hydrazone Ligands: Preparation, Structure, and Catalytic Activity in Cyanosilylether Synthesis under an Air Atmosphere. Inorg Chem 2023. [PMID: 37310847 DOI: 10.1021/acs.inorgchem.3c00819] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
A new class of N,O-coordinate half-sandwich ruthenium complexes supported by hydrazone ligands with a general formula of [Ru(η6-p-cymene)Cl(L)] have been obtained in moderate to excellent yields conveniently. These air- and moisture-stable ruthenium complexes exhibited excellent catalytic activity in cyanosilylether synthesis under mild reaction conditions. Under the catalysis of ruthenium, various cyanosilylethers with different substituents were obtained through a one-pot reaction of trimethylsilyl cyanide with carbonyl substrates, with good to excellent yields. Excellent catalytic efficiency, a wide substrate range, and mild reaction conditions made this type of ruthenium catalyst have potential for industrial application. All of the half-sandwich ruthenium complexes have been well described by infrared, nuclear magnetic resonance, and EA analysis. Molecular structures of ruthenium complexes 1 and 4 were confirmed by single-crystal X-ray analysis.
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Affiliation(s)
- Ke Wang
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China
| | - Heng Li
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China
| | - Lin Yang
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China
| | - Zhen-Jiang Liu
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China
| | - Zi-Jian Yao
- School of Chemical and Environmental Engineering, Shanghai Institute of Technology, Shanghai 201418, China
- Anhui Laboratory of Molecular-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu 241002, China
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2
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Role of metal center and coordination environment in M-(Z)-N-((E)-pyridin-2-ylmethylene)isonicotinohydrazonate (M = LaIII, ZnII, CdII or HgII) catalyzed cyanosilylation of aldehydes. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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3
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Vinoth G, Indira S, Bharathi M, Alves LG, Martins AM, Shanmuga Bharathi K. Cyanosilylation of carbonyl compounds catalyzed by half-sandwich (η6-p-cymene) Ruthenium(II) complexes bearing heterocyclic hydrazone derivatives. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2020.120006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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4
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Ma Z, Aliyeva VA, Tagiev DB, Zubkov FI, Guseinov FI, Mahmudov KT, Pombeiro AJ. Multinuclear Zn(II)-arylhydrazone complexes as catalysts for cyanosilylation of aldehydes. J Organomet Chem 2020. [DOI: 10.1016/j.jorganchem.2020.121171] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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5
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Mohammadi O, Golestanzadeh M, Abdouss M. Metal‐Free and Ultrasound‐Assisted C–C and O‐Si (O‐Protected) Bond Formation in Cyanosilylation of Aldehydes with TMSCN Catalyzed by Functionalized Graphene Oxide Derivatives. ChemistrySelect 2018. [DOI: 10.1002/slct.201803217] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ozra Mohammadi
- Department of ChemistryAmirkabir University of Technology (Tehran Polytechnic) 158754413, Tehran Iran
| | - Mohsen Golestanzadeh
- Department of ChemistryAmirkabir University of Technology (Tehran Polytechnic) 158754413, Tehran Iran
- Department of Organic ChemistryFaculty of ChemistryUniversity of Kashan 8731551167, Kashan Iran
- Child Growth and Development Research CenterResearch Institute for Primordial Prevention of Non-Communicable DiseaseIsfahan University of Medical Sciences, Isfahan 8174673461 I. R. Iran
| | - Majid Abdouss
- Department of ChemistryAmirkabir University of Technology (Tehran Polytechnic) 158754413, Tehran Iran
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6
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Cyanosilylation of aldehydes catalyzed by lanthanide derivatives comprising arylhydrazones of β-diketones. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2017.08.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Gurbanov AV, Maharramov AM, Zubkov FI, Saifutdinov AM, Guseinov FI. Cyanosilylation of Aldehydes Catalyzed by Iron(III) Arylhydrazone-β-Diketone Complexes. Aust J Chem 2018. [DOI: 10.1071/ch17595] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Two known iron(iii) complexes, [Fe(H2O)3(L1)]·xH2O (x = 4 (1), 5 (2)) and [Fe(H2O)3(L2)]·3H2O (3), bearing the basic forms of 5-chloro-3-(2-(4,4-dimethyl-2,6-dioxocyclohexylidene)hydrazinyl)-2-hydroxybenzenesulfonic acid (H3L1) and 3-(2-(2,4-dioxopentan-3-ylidene)hydrazinyl)-2-hydroxy-5-nitrobenzenesulfonic acid (H3L2), were prepared and used as homogeneous catalysts for cyanosilylation of a variety of aldehydes with trimethylsilyl cyanide leading to the corresponding cyanohydrin trimethylsilyl ethers. High yield (up to 98 %) was observed in the reaction catalyzed by 3 at room temperature in methanol.
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8
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Gurbanov AV, Huseynov FE, Maharramov AM, Guedes da Silva MFC, Pombeiro AJ. Cyanosilylation of aldehydes catalyzed by arylhydrazone di- and triorganotin(IV) complexes. J Organomet Chem 2017. [DOI: 10.1016/j.jorganchem.2017.07.030] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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9
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Yadav GD, Deepa, Singh S. 1,4-Diazabicyclo[2.2.2]octane Trifluoroacetate: A Highly Efficient Organocatalyst for the Cyanosilylation of Carbonyl Compounds under Solvent Free Condition. ChemistrySelect 2017. [DOI: 10.1002/slct.201700674] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Geeta Devi Yadav
- Department of Chemistry; University of Delhi; Delhi 110007 India
| | - Deepa
- Department of Chemistry; University of Delhi; Delhi 110007 India
| | - Surendra Singh
- Department of Chemistry; University of Delhi; Delhi 110007 India
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10
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Lin ZC, Chen C. Asymmetric Synthesis of a New Salen Type-titanium Complex as the Catalyst for Asymmetric Trimethylsilylcyanation of Aldehydes. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.201000101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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11
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12
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De novo synthesis of differentially protected l-iduronic acid glycosylating agents. Carbohydr Res 2010; 345:948-55. [DOI: 10.1016/j.carres.2010.02.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 02/02/2010] [Accepted: 02/03/2010] [Indexed: 11/23/2022]
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13
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Brown LE, Landaverry YR, Davies JR, Milinkevich KA, Ast S, Carlson JS, Oliver AG, Konopelski JP. Progress toward the total synthesis of psymberin/irciniastatin A. J Org Chem 2009; 74:5405-10. [PMID: 19572569 DOI: 10.1021/jo9009003] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this paper, we describe our synthesis of four key building blocks for the total synthesis of psymberin (1) and its C4 epimer (2). Despite early difficulties in processing material to the advanced intermediate stage, we have been successful in developing high-yielding syntheses for the pyran core, natural side chain, 4-epi side chain, and aryl fragments of the molecule. Our findings from the optimization process are presented herein.
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Affiliation(s)
- Lauren E Brown
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Santa Cruz, California 95064, USA
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14
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Gawronski J, Wascinska N, Gajewy J. Recent progress in Lewis base activation and control of stereoselectivity in the additions of trimethylsilyl nucleophiles. Chem Rev 2009; 108:5227-52. [PMID: 18850749 DOI: 10.1021/cr800421c] [Citation(s) in RCA: 251] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jacek Gawronski
- Department of Chemistry, A. Mickiewicz University, Poznań, Poland
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15
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North M, Usanov DL, Young C. Lewis acid catalyzed asymmetric cyanohydrin synthesis. Chem Rev 2009; 108:5146-226. [PMID: 19067648 DOI: 10.1021/cr800255k] [Citation(s) in RCA: 286] [Impact Index Per Article: 19.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Michael North
- School of Chemistry, Bedson Building, Newcastle University, Newcastle upon Tyne, NE1 7RU, United Kingdom.
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Kumaraswamy G, Ankamma K. IMPROVED THREE-COMPONENT LEWIS ACID-FREE APPROACH FOR THE SYNTHESIS OF PROTECTED RACEMIC CYANOHYDRINS. ORG PREP PROCED INT 2008. [DOI: 10.1080/00304940809458105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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17
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Majhi A, Kim SS, Kim HS. Copper perchlorate hexahydrate: a highly efficient catalyst for the cyanosilylation of aldehydes. Appl Organomet Chem 2008. [DOI: 10.1002/aoc.1416] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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18
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Alcaide B, Almendros P, Cabrero G, Ruiz MP. Stereocontrolled Access to Orthogonally Protected anti,anti-4-Aminopiperidine-3,5-diols through Chemoselective Reduction of Enantiopure β-Lactam Cyanohydrins. J Org Chem 2007; 72:7980-91. [PMID: 17867703 DOI: 10.1021/jo701452a] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The cyanosilylation of enantiopure 4-oxoazetidine-2-carbaldehydes with tert-butyldimethylsilyl cyanide was promoted by either molecular sieves or catalytic amount of sodium carbonate to give O-silylated beta-lactam cyanohydrins with good yield and diastereoselectivity. In contrast, Lewis acids did not effectively promote the cyanosilylation under different experimental conditions, and instead hydrocyanation took place affording the corresponding free cyanohydrins in variable yield and selectivity. Starting from beta-lactam cyanohydrin hybrids, two concise, complementary stereocontrolled routes to optically pure orthogonally protected anti,anti-4-amino-3,5-piperidine diols were achieved. Key features of the first approach include chemoselective reductive opening of the beta-lactam ring with LiBH4 to a 3-amino-5-hydroxy pentanenitrile followed by reductive cyclization of a conveniently functionalized cyanomesylate derivative with NaBH4/NiCl2. The second approach involves LiAlH4 reduction of protected anti,anti-4-amino-3,5-dihydroxypiperidin-2-ones, which were easily obtained by chemoselective reduction of the cyano group in the beta-lactam cyanohydrin hybrids with NaBH4/NiCl2 and subsequent intramolecular rearrangement of the resulting amino beta-lactams. Both routes make use of an oxidative N-dearylation with diacetoxyiodobenzene of a 4-methoxyphenylamino group as a common synthetic step. Specifically, the utility of this novel reaction sequence has been demonstrated by the synthesis of fully orthogonally protected sialidase inhibitors.
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Affiliation(s)
- Benito Alcaide
- Departamento de Química Orgánica I, Facultad de Química, Universidad Complutense de Madrid, 28040 Madrid, Spain.
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19
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Fe(Cp)2PF6: An efficient catalyst for cyanosilylation of carbonyl compounds under solvent free condition. J Organomet Chem 2007. [DOI: 10.1016/j.jorganchem.2007.07.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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20
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Adibekian A, Bindschädler P, Timmer MSM, Noti C, Schützenmeister N, Seeberger PH. De Novo Synthesis of Uronic Acid Building Blocks for Assembly of Heparin Oligosaccharides. Chemistry 2007; 13:4510-22. [PMID: 17444537 DOI: 10.1002/chem.200700141] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
An efficient de novo synthesis of uronic acid building blocks is described. The synthetic strategy relies on the stereoselective elongation of thioacetal protected dialdehydes 12 a and 17. The dialdehydes are prepared from D-xylose, a cheap and commercially available source. A highly stereoselective MgBr(2)OEt(2)-mediated Mukaiyama aldol addition to C4-aldehyde 12 a is performed to obtain D-glucuronic acid building block 16, whereas L-iduronic acid building block 22 is prepared by MgBr(2)OEt(2)-mediated cyanation of C5-aldehyde 17. Synthesis of a heparin disaccharide demonstrates the utility of the de novo strategy for the assembly of glycosaminoglycan oligosaccharides.
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Affiliation(s)
- Alexander Adibekian
- Laboratory for Organic Chemistry, Swiss Federal Institute of Technology ETH Zürich, Wolfgang-Pauli-Strasse 10, HCI F312, 8093 Zürich, Switzerland
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21
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Mojtahedi MM, Abaee MS, Bolourtchian M, Abbasi H. Facile Room-Temperature MgBr2· OEt2-Catalyzed Thiolysis of Epoxides Under Solvent-Free Conditions. PHOSPHORUS SULFUR 2007. [DOI: 10.1080/10426500601088697] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Mohammad M. Mojtahedi
- a Organosilicon Laboratory , Chemistry and Chemical Engineering Research Center of Iran , Tehran , Iran
| | - M. Saeed Abaee
- a Organosilicon Laboratory , Chemistry and Chemical Engineering Research Center of Iran , Tehran , Iran
| | - Mohammad Bolourtchian
- a Organosilicon Laboratory , Chemistry and Chemical Engineering Research Center of Iran , Tehran , Iran
| | - Hassan Abbasi
- a Organosilicon Laboratory , Chemistry and Chemical Engineering Research Center of Iran , Tehran , Iran
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22
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Abaee MS, Mojtahedi MM, Zahedi MM, Sharifi R. A highly efficient method for solvent-free synthesis of bisarylmethylidenes of pyranones and thiopyranones. HETEROATOM CHEMISTRY 2007. [DOI: 10.1002/hc.20252] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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23
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Aljarilla A, Córdoba R, Csaky AG, Fernández I, López Ortiz F, Plumet J, Ruiz Gómez G. Stereochemistry of the Tetrabutylammonium Cyanide-Catalyzed Cyanosylilation of Cyclic α,β-Epoxyketones – Dependence of the Diastereoselectivity on the Ring Size. European J Org Chem 2006. [DOI: 10.1002/ejoc.200600239] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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24
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Mojtahedi MM, Abbasi H, Abaee MS. MgBr2·OEt2 mediated protection of alcohols with hexamethyldisilazane: An efficient catalytic route for the preparation of silyl ethers under solvent-free conditions. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.molcata.2006.01.024] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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25
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A C2-symmetric chiral bipyridyldiol–titanium complex as a catalyst for the asymmetric trimethylsilylcyanation of substituted benzaldehydes. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.tetasy.2005.05.035] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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26
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Gama Á, Flores-López LZ, Aguirre G, Parra-Hake M, Somanathan R, Cole T. A study of substituent effects on the enantioselective trimethylsilylcyanation of benzaldehyde catalyzed by chiral Schiff base–titanium(IV) complexes. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/j.tetasy.2005.01.030] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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27
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Amurrio I, Córdoba R, Csákÿ AG, Plumet J. Tetrabutylammonium cyanide catalyzed diasteroselective cyanosilylation of chiral α-hydroxyketones. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.07.101] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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28
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Uang BJ, Fu IP, Hwang CD, Chang CW, Yang CT, Hwang DR. Development of β-hydroxyamide/titanium complexes for catalytic enantioselective silylcyanation of aldehydes. Tetrahedron 2004. [DOI: 10.1016/j.tet.2004.08.083] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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29
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Li G, Pandey SK, Graham A, Dobhal MP, Mehta R, Chen Y, Gryshuk A, Rittenhouse-Olson K, Oseroff A, Pandey RK. Functionalization of OEP-Based Benzochlorins To Develop Carbohydrate-Conjugated Photosensitizers. Attempt To Target β-Galactoside-Recognized Proteins. J Org Chem 2003; 69:158-72. [PMID: 14703392 DOI: 10.1021/jo030280b] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
meso-(2-Formylvinyl)octaethylporphyrin on reaction with cyanotrimethylsilane in the presence of various catalysts [copper triflate [Cu(OTf)(2)], indium triflate [In(OTf)(3)], or magnesium bromide diethyl etherate (MgBr(2).Et(2)O)] produced a mixture of the intermediate 3-hydroxy-3-cyanopropenoporphyrin, the corresponding trimethylsilyl ether derivative, and the unexpected propenochlorins. The yields of the reaction products were found to depend on the reaction conditions and the catalysts used. The intermediate porphyrins on treatment with concentrated sulfuric acid yielded the free-base cyanobenzochlorins in major quantity along with several other novel benzochlorins as minor products. Reduction of ethyl-3-hydroxy-1-pentenoate-porphyrin with DIBAL-H/NaBH(4) and subsequent acid treatment provided the corresponding free-base 10(3)-(2-hydroxyethyl)benzochlorin, which upon a sequence of reactions gave a free-base benzochlorin bearing a carboxylic acid functionality in good yield. It was then condensed with a variety of carbohydrates (glucosamine, galactosamine, and lactosamine), and the related conjugates were screened using the galectin-binding-ability assay. Among the carbohydrate conjugates investigated, the lactose and galactose analogues displayed the galectin-binding ability with an enhancement of about 300-400-fold compared to lactose. In preliminary studies, all photosensitizers (with or without carbohydrate moieties) were found to be active in vitro [radiation-induced fibrosarcoma (RIF) tumor cells]. However, the cells incubated with lactose (known to bind to beta-galactoside-recognized proteins) prior to the addition of the photosensitizers containing the beta-galactose moiety (e.g., galactose and lactose) produced a 100% decrease in their photosensitizing efficacy. Under similar experimental conditions, benzochlorin without a beta-galactoside moiety or the related glucose conjugate did not show any inhibition in its photosensitizing efficacy. These results in combination with the galectin-binding data indicate a possible beta-galactoside-recognized protein specificity of the galactose- and lactose-benzochlorin conjugates.
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Affiliation(s)
- Guolin Li
- Chemistry Division Photodynamic Therapy Center, Department of Dermatology, Roswell Park Cancer Institute, Buffalo, New York 14263, USA
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Azizi N, Saidi MR. An improved synthesis of cyanohydrins in the presence of solid LiClO4 under solvent-free conditions. J Organomet Chem 2003. [DOI: 10.1016/j.jorganchem.2003.09.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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31
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Flores-Morales V, Fernández-Zertuche M, Ordóñez M. Highly diastereoselective addition of Et2AlCN to β-keto amides derived from (S)-4-isopropyl-2-oxazolidinone. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/j.tetasy.2003.07.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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32
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Iodine as novel reagent for the 1,2-addition of trimethylsilyl cyanide to ketones including α,β-unsaturated ketones. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)02321-3] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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33
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Ward DE, Sales M, Hrapchak MJ. Attempted enantiotopic group selective cyanohydrin formation from α-alkoxy aldehydes by double stereodifferentiation. CAN J CHEM 2001. [DOI: 10.1139/v01-151] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Enantiotopic group selectivity can result from the competition between substrate and reagent double stereodifferentiation. We have examined this approach for enantioselective hydrocyanation of racemic α-alkoxy aldehydes (e.g., 2-(phenylmethoxy)heptanal (1)). Reaction of 1 with TMSCN mediated by chiral nonracemic alkoxy Ti(IV) reagents under conditions known to be reasonably enantioface selective in reactions with achiral aldehydes, proceeded with very low enantiotopic group selectivity (<2:1). It was established that TMSCN can react with Ti(IV) reagents to produce "TiCN" adducts that are capable of hydrocyanation but with low substrate-controlled diastereoselectivity in reactions with 1. The poor enantiotopic group selectivity observed can be rationalized to result from this low diastereoselectivity despite the respectable levels of enantioface selectivity associated with these reagents in hydrocyanation of achiral aldehydes. Highly diastereoselective hydrocyanation of α-alkoxy aldehydes can be achieved with TMSCN in the presence of excess MgBr2·OEt2. High diastereoselectivity was also observed using achiral and chiral TiCN adducts in place of TMSCN. Although the putative TiCN adducts obtained from nonracemic alkoxy Ti(IV) reagents are implicated in enantioface selective hydrocyanation, these reagents were not enantiotopic group selective under these conditions and showed no evidence of double stereodifferentiation. The use of nonracemic bisoxazoline ligands for Mg(II) was also ineffective.Key words: cyanohydrin, 2-alkoxyalkanal, double stereodifferentiation, enantiotopic group selective reaction, kinetic resolution.
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Bandini M, Cozzi PG, Melchiorre P, Umani-Ronchi A. Indium tribromide: a highly effective catalyst for the addition of trimethylsilyl cyanide to α-hetero-substituted ketones. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)00368-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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35
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Bianchi P, Roda G, Riva S, Danieli B, Zabelinskaja-Mackova A, Griengl H. On the selectivity of oxynitrilases towards α-oxygenated aldehydes. Tetrahedron 2001. [DOI: 10.1016/s0040-4020(01)00054-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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