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Oiarbide M, Palomo C. Brønsted Base-Catalyzed Enantioselective α-Functionalization of Carbonyl Compounds Involving π-Extended Enolates. CHEM REC 2023; 23:e202300164. [PMID: 37350363 DOI: 10.1002/tcr.202300164] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/06/2023] [Indexed: 06/24/2023]
Abstract
Chiral Brønsted base (BB) catalyzed asymmetric transformations constitute an important tool for synthesis. A meaningful fraction of these transformations proceeds through transiently generated enolate intermediates, which display quite versatile reactivity against a variety of electrophiles. Some years ago, our group became interested in developing BB-catalyzed asymmetric reactions of enolizable carbonyl substrates that involve π-extended enolates in which, besides control of reaction diastereo and enantioselectivity, the site-selectivity control is an additional issue in most cases. In the examples covered in this account the opportunities deployed, and the challenges posed, by these methods are illustrated, with a focus on the generation of quaternary carbon stereocenters. In the way, new bifunctional BB catalysts as well as achiral templates were developed that may find further applications.
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Affiliation(s)
- Mikel Oiarbide
- Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018 San Sebastián, Spain
| | - Claudio Palomo
- Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018 San Sebastián, Spain
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More M, Joshi P, Mishra Y, Khanna P. Metal complexes driven from Schiff bases and semicarbazones for biomedical and allied applications: a review. MATERIALS TODAY. CHEMISTRY 2019; 14:100195. [PMID: 32289101 PMCID: PMC7110249 DOI: 10.1016/j.mtchem.2019.100195] [Citation(s) in RCA: 96] [Impact Index Per Article: 19.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/07/2019] [Accepted: 09/01/2019] [Indexed: 05/22/2023]
Abstract
Schiff bases are versatile organic compounds which are widely used and synthesized by condensation reaction of different amino compound with aldehydes or ketones known as imine. Schiff base ligands are considered as privileged ligands as they are simply synthesized by condensation. They show broad range of application in medicine, pharmacy, coordination chemistry, biological activities, industries, food packages, dyes, and polymer and also used as an O2 detector. Semicarbazone is an imine derivative which is derived from condensation of semicarbazide and suitable aldehyde and ketone. Imine ligand-containing transition metal complexes such as copper, zinc, and cadmium have shown to be excellent precursors for synthesis of metal or metal chalcogenide nanoparticles. In recent years, the researchers have attracted enormous attention toward Schiff bases, semicarbazones, thiosemicarbazones, and their metal complexes owing to numerous applications in pharmacology such as antiviral, antifungal, antimicrobial, antimalarial, antituberculosis, anticancer, anti-HIV, catalytic application in oxidation of organic compounds, and nanotechnology. In this review, we summarize the synthesis, structural, biological, and catalytic application of Schiff bases as well as their metal complexes.
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Key Words
- 2,6-DAPBPTSC, 2,6-diacetylpyridine bis-4-phenyl-3-thiosemicarbazone
- 35-DTBP, 3,5-di-tert-butylphenol
- 3CLpro, 3C-like protease
- ATNR, Amine terminated liquid natural rubber
- ATT, 2-acetylthiophene thiosemicarbazone
- BBPT, Biacetyl bis(4-phenyl-3-thiosemicarbazone)
- BBTSC, Benzyloxybenzaldehyde thiosemicarbazone
- BCG, Bacillus calmette-guérine
- BDT, Benzyldithiosemicarbazone
- BGPT, Bipyridyl glyoxal bis(4-phenyl-3-thiosemicarbazone)
- BMTS, Biacetyl monothiosemicarbazone
- Biological/biomedical activities
- Bipy, 2,2-bipyridine
- CT DNA, Calf thymus deoxyribonucleic acid
- DAPY, 2,3-diamino-pyridine
- DTBP, 2,6-di-tert-butylphenol
- DTBQ, 2,6-di-tert-butyl-4,4′-benzoquinone
- EAC, Enrichlish Ascitices Cells
- HEK-293, Human Embryonic Kidney cells
- HL-60, Human leukemia-60 cell line
- HeLa, immortal cell lines
- HepG2, Hepatic cellular carcinoma cells (Human liver cancer cell line)
- IgG, Immunoglobin G
- K B HCT-8, Human colon cancer cell line
- M-IBDET, N-methylisatin-β-4′,4′-diethylthiosemicarbazone
- MCF-7, Michigan Cancer Foundation-7
- MCF7 cells, Michigan Cancer Foundation-7 (breast cancer cell line)
- MHV, Mouse hepatitis virus
- MLV, Moloney leukemia virus
- MSOPD, N,N-bis(3-methylsalicylidene)-ortho-phenylenediamine
- Metal complexes
- NQSC, Naphthoquinone semicarbazone
- NQTS, ortho-Naphthoquinone thiosemicarbazone
- OLED, Organic light emitting diode
- PAS, p-amino salicylic acid
- PPTS, Picolinealdehyde-4-phenyl-3-thiosemicarbazone
- Phen, 1,10-phenanthroline
- SARS CoV, Severe Acute Respiratory Syndrome coronavirus
- SARS, Severe acute respiratory syndrome
- SB-HAG, Schiff bases of hydroxyamino guanidines
- SK-MEL-30, Human Melanoma Cell Line
- SK-OV-3 cells, Ovarian cancer cell line
- SSB-HAG, salicylaldehyde Schiff bases of HAG
- Schiff base
- Semicarbazone
- TCIDw, Tissue culture Infective Dose
- TTBDQ, 3,5,3′,5′-tetra-tert-butyl-4,4′-diphenoquinone
- VSV, vesicular stomatitis virus
- scCO2, Super-critical carbon dioxide
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Affiliation(s)
- M.S. More
- Nanochemistry/QDs R & D Laboratory, Department of Applied Chemistry, Defence Institute of Advanced Technology (DIAT), Ministry of Defence, DRDO, Government of India, Girinagar, Pune, 411025, India
| | - P.G. Joshi
- Nanochemistry/QDs R & D Laboratory, Department of Applied Chemistry, Defence Institute of Advanced Technology (DIAT), Ministry of Defence, DRDO, Government of India, Girinagar, Pune, 411025, India
| | - Y.K. Mishra
- Institute for Materials Science, Kiel University, Kaiserstrasse. 2, Kiel, 24143, Germany
- NanoSYD, Mads Clausen Institute, University of Southern Denmark, Alsion 2, 6400, Sønderborg, Denmark
| | - P.K. Khanna
- Nanochemistry/QDs R & D Laboratory, Department of Applied Chemistry, Defence Institute of Advanced Technology (DIAT), Ministry of Defence, DRDO, Government of India, Girinagar, Pune, 411025, India
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Nag P, Sharma D. Synthesis, characterization and anticandidal activity of dioxomolybdenum(VI) complexes of the type [MoO2{ON=C(CH3)Ar}2] and [MoO2{OC(R)CHC(R’)=NC6H5}2]. Heliyon 2019; 5:e01729. [PMID: 31193463 PMCID: PMC6529711 DOI: 10.1016/j.heliyon.2019.e01729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 03/15/2019] [Accepted: 05/10/2019] [Indexed: 11/22/2022] Open
Abstract
Interaction of [MoO2(acac)2] with internally functionalized oximes like HON=C(CH3)Ar (Ar = C4H3S, C4H3O or C5H4N) and Schiff's Bases derived from β – diketones like HOC(R)CHC(R′)=NC6H5 (R = R’ = CH3 or C6H5; R = CH3 and R’ = C6H5) led to the formation of yellow dioxomolybdenum(VI) complexes of the type [MoO2{ON=C(CH3)Ar}2] and [MoO2{OC(R)CHC(R′)=NC6H5}2]. Oximes were synthesized by green methodology. The newly synthesized complexes were characterized on basis of elemental analysis and various spectral findings. Anticandidal activity of [MoO2{ON=C(CH3)C6H4N}2] clearly reveals that the complex is biologically active against fungal diseases.
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Abstract
Since the beginning of the 20th century, numerous research efforts made elegant use of barbituric acid derivatives as building blocks for the elaboration of more complex and useful molecules in the field of pharmaceutical chemistry and material sciences. However, the construction of chiral scaffolds by the catalytic enantioselective transformation of barbituric acid and derivatives has only emerged recently. The specific properties of these rather planar scaffolds, which also encompass either a high Brønsted acidity concerning the native barbituric acid or the marked electrophilic character of alkylidene barbituric acids, required specific developments to achieve efficient asymmetric processes. This review covers the enantioselective catalytic reactions developed for barbituric acid platforms using an organocatalytic and metal-based enantioselective sequences. These achievements currently allow several unique addition and annulation reactions towards the construction of high valued chiral heterocycles from barbituric acid derivatives along with innovative enantioselective developments.
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Mardani HR, Ziari M. Synthesis and characterization of a new nanomagnetic coordination composite from Fe3O4 and Cu(II) complex: as an efficient catalyst in oxidation of benzyl alcohol. RESEARCH ON CHEMICAL INTERMEDIATES 2018. [DOI: 10.1007/s11164-018-3511-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Li SW, Kang Q. Catalytic asymmetric synthesis of diphenylbutazone analogues. Chem Commun (Camb) 2018; 54:10479-10482. [DOI: 10.1039/c8cc06426a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The asymmetric Michael addition of diphenylbutazone and its analogues to α,β-unsaturated 2-acyl imidazoles has been developed with a chiral-at-metal Rh(iii) complex as a catalyst.
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Affiliation(s)
- Shi-Wu Li
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology
- Fujian Institute of Research on the Structure of Matter
- Chinese Academy of Sciences
- Fuzhou
- P. R. China
| | - Qiang Kang
- Key Laboratory of Coal to Ethylene Glycol and Its Related Technology
- Fujian Institute of Research on the Structure of Matter
- Chinese Academy of Sciences
- Fuzhou
- P. R. China
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Del Pozo S, Vera S, Oiarbide M, Palomo C. Catalytic Asymmetric Synthesis of Quaternary Barbituric Acids. J Am Chem Soc 2017; 139:15308-15311. [PMID: 29023111 DOI: 10.1021/jacs.7b09124] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The catalytic asymmetric α-functionalization of prochiral barbituric acids, a subtype of pseudosymmetric 1,3-diamides, to yield the corresponding 5,5-disubstituted (quaternary) derivatives remains essentially unsolved. In this study 2-alkylthio-4,6-dioxopirimidines are designed as key 1,3-diamide surrogates that perform exceedingly in amine-squaramide catalyzed C-C bond forming reactions with vinyl ketones or Morita-Baylis-Hillmann-type allyl bromides as electrophiles. Mild acid hydrolysis of adducts affords barbituric acid derivatives with an in-ring quaternary carbon in unprecedented enantioselectivity, offering valuable materials for biological evaluations.
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Affiliation(s)
- Sandra Del Pozo
- Departamento de Química Orgánica I, Universidad del País Vasco , Manuel de Lardizabal 3, 2018 San Sebastián, Spain
| | - Silvia Vera
- Departamento de Química Orgánica I, Universidad del País Vasco , Manuel de Lardizabal 3, 2018 San Sebastián, Spain
| | - Mikel Oiarbide
- Departamento de Química Orgánica I, Universidad del País Vasco , Manuel de Lardizabal 3, 2018 San Sebastián, Spain
| | - Claudio Palomo
- Departamento de Química Orgánica I, Universidad del País Vasco , Manuel de Lardizabal 3, 2018 San Sebastián, Spain
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Liu Y, Zhang Y, Duan HX, Wanyan DY, Wang YQ. Enantioselective organocatalytic Michael additions of N,N'-dialkylbarbituric acids to enones. Org Biomol Chem 2017; 15:8669-8679. [PMID: 28990625 DOI: 10.1039/c7ob02116j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
N,N'-Dialkylbarbituric acids as cyclic malonamide donors were successfully used in the enantioselective Michael addition reaction of enones. Using cinchona alkaloid-based bifunctional squaramide as an organocatalyst, this Michael reaction of N,N'-di-tert-butylbarbituric acid with various enones features a highly enantioselective (91-99% ee) production of the corresponding optically active 5-substituted barbituric acid derivatives. The transformations of the Michael product for the barbituric acid structural unit were realized in two ways, deprotection to remove the N-tert-butyl group and alkylation to produce 5,5-disubstituted barbituric acid derivatives.
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Affiliation(s)
- Ying Liu
- Provincial Key Laboratory of Polyoxometalate Chemistry, Provincial Key Laboratory of Natural Medicine and Immuno-Engineering, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, Henan 475004, P. R. China.
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Rombola M, Sumaria CS, Montgomery TD, Rawal VH. Development of Chiral, Bifunctional Thiosquaramides: Enantioselective Michael Additions of Barbituric Acids to Nitroalkenes. J Am Chem Soc 2017; 139:5297-5300. [PMID: 28375610 DOI: 10.1021/jacs.7b01115] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report a general method for the synthesis of chiral thiosquaramides, a class of bifunctional catalysts not previously described in the literature. Thiosquaramides are found to be more acidic and significantly more soluble in nonpolar solvents than their oxosquaramide counterparts, and they are excellent catalysts for the unreported, enantioselective conjugate addition reaction of the barbituric acid pharmacaphore to nitroalkenes, delivering the chiral barbiturate derivatives in high yields and high enantioselectivities, even with catalyst loadings as low as 0.05 mol%.
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Affiliation(s)
- Michael Rombola
- Department of Chemistry, University of Chicago , 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Chintan S Sumaria
- Department of Chemistry, University of Chicago , 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Thomas D Montgomery
- Department of Chemistry, University of Chicago , 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
| | - Viresh H Rawal
- Department of Chemistry, University of Chicago , 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
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Odyakov VF, Zhizhina EG, Rodikova YA, Gogin LL. Mo-V-Phosphoric Heteropoly Acids and Their Salts: Aqueous Solution Preparation - Challenges and Perspectives. Eur J Inorg Chem 2015. [DOI: 10.1002/ejic.201500359] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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11
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Hastings SD, Byrd H, Gray LN, Jablonsky MJ, Freeman JL, Gray GM. Multinuclear NMR Spectroscopic and X‐ray Crystallographic Studies of Electronic and Steric Effects of Phosphonous Acid Ligands and Their Chlorophosphite Ligand Precursors in Tungsten Pentacarbonyl Complexes. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201300121] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Samantha D. Hastings
- Department of Chemistry, University of Alabama at Birmingham, 901 14th Street South, Birmingham, AL 35294‐1240, USA, Fax: +1‐205‐934‐2543, http://www.uab.edu/chemistry/
| | - Houston Byrd
- Department of Chemistry, University of Montevallo, Harman Hall, Station 6480, Montevallo, AL 35115, USA
| | - Leanne N. Gray
- Department of Chemistry, University of Montevallo, Harman Hall, Station 6480, Montevallo, AL 35115, USA
| | - Michael J. Jablonsky
- Department of Chemistry, University of Alabama at Birmingham, 901 14th Street South, Birmingham, AL 35294‐1240, USA, Fax: +1‐205‐934‐2543, http://www.uab.edu/chemistry/
| | - Jason L. Freeman
- Department of Chemistry, University of Alabama at Birmingham, 901 14th Street South, Birmingham, AL 35294‐1240, USA, Fax: +1‐205‐934‐2543, http://www.uab.edu/chemistry/
| | - Gary M. Gray
- Department of Chemistry, University of Alabama at Birmingham, 901 14th Street South, Birmingham, AL 35294‐1240, USA, Fax: +1‐205‐934‐2543, http://www.uab.edu/chemistry/
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12
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Beck W. Metal Complexes of Biologically Important Ligands, CLXXVI.[1] Formation of Peptides within the Coordination Sphere of Metal Ions and of Classical and Organometallic Complexes and Some Aspects of Prebiotic Chemistry. Z Anorg Allg Chem 2011. [DOI: 10.1002/zaac.201100137] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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13
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Deuss PJ, den Heeten R, Laan W, Kamer PCJ. Bioinspired Catalyst Design and Artificial Metalloenzymes. Chemistry 2011; 17:4680-98. [DOI: 10.1002/chem.201003646] [Citation(s) in RCA: 166] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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14
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Thibault MH, Lucier BE, Schurko RW, Fontaine FG. Synthesis and solid-state characterization of platinum complexes with hexadentate amino- and iminophosphine ligands. Dalton Trans 2009:7701-16. [DOI: 10.1039/b907737e] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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15
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Biradar DB, Gau HM. Highly enantioselective conjugate addition of diethylzinc to substituted chalcones catalyzed by Cu(II) complexes of a tridentate P,N,O ligand. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.tetasy.2008.02.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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16
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Lu Z, Ma S. Metal-catalyzed enantioselective allylation in asymmetric synthesis. Angew Chem Int Ed Engl 2008; 47:258-97. [PMID: 17968865 DOI: 10.1002/anie.200605113] [Citation(s) in RCA: 1202] [Impact Index Per Article: 75.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Metal-catalyzed enantioselective allylation, which involves the substitution of allylic metal intermediates with a diverse range of different nucleophiles or S(N)2'-type allylic substitution, leads to the formation of C-H, -C, -O, -N, -S, and other bonds with very high levels of asymmetric induction. The reaction may tolerate a broad range of functional groups and has been applied successfully to the synthesis of many natural products and new chiral compounds.
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Affiliation(s)
- Zhan Lu
- Laboratory of Molecular Recognition and Synthesis, Department of Chemistry, Zhejiang University, Hangzhou 310027, Zhejiang, China
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Lu Z, Ma S. Metallkatalysierte enantioselektive Allylierungen in der asymmetrischen Synthese. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200605113] [Citation(s) in RCA: 405] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Gavrilov KN, Polosukhin AI. Chiral P,N-bidentate ligands in coordination chemistry and organic catalysis involving rhodium and palladium. RUSSIAN CHEMICAL REVIEWS 2007. [DOI: 10.1070/rc2000v069n08abeh000559] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Abstract
Palladium-catalyzed asymmetric allylic alkylation of nonstabilized ketone enolates to generate quaternary centers has been achieved in excellent yield and enantioselectivity. Optimized conditions consist of performing the reaction in the presence of two equivalents of LDA as base, one equivalent of trimethytin chloride as a Lewis acid, 1,2-dimethoxyethane as the solvent, and a catalytic amount of a chiral palladium complex formed from pi-allyl palladium chloride dimer 3 and cyclohexyldiamine derived chiral ligand 4. Linearly substituted, acyclic 1,3-dialkyl substituted, and unsubstituted allylic carbonates function well as electrophiles. A variety of alpha-tetralones, cyclohexanones, and cyclopentanones can be employed as nucleophiles. The absolute configuration generated is consistent with the current model in which steric factors control stereofacial differentiation. The quaternary substituted products available by this method are versatile substrates for further elaboration.
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Affiliation(s)
- Barry M Trost
- Department of Chemistry, Stanford University, Stanford, CA 94305-5080, USA.
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Danjo H, Higuchi M, Yada M, Imamoto T. P-stereogenic P/N hybrid ligands: a remarkable switch in enantioselectivity in palladium-catalyzed asymmetric allylation. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2003.10.160] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Brunner H, Schönherr M, Zabel M. Enantioselective catalysis. Part 148: Carbohydrate-derived oxime ethers stable towards hydrolysis—syntheses of ligands and complexes and a study of their catalytic properties. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0957-4166(03)00093-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Brunner H, Klankermayer J, Zabel M. Optically Active Transition Metal Complexes. 128 [1] Synthesis, Characterization and Molecular Structures of Cycloheptatrienyl-Iminphos-Molybdenum Complexes Differing Only in the Metal Configuration. Z Anorg Allg Chem 2002. [DOI: 10.1002/1521-3749(200211)628:11<2264::aid-zaac2264>3.0.co;2-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Chandrasekaran A, Timosheva NV, Day RO, Holmes RR. Pseudoheptacoordination and pseudohexacoordination in tris(2-N,N-dimethylbenzylamino)phosphane. Inorg Chem 2002; 41:5235-40. [PMID: 12354057 DOI: 10.1021/ic020153i] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The phosphane (C(6)H(4)-2-CH(2)NMe(2))(3)P (1) upon recrystallization from various solvents yielded the structurally different forms 1A, 1C, 1B(1), and 1B(2). Phosphane oxide (C(6)H(4)-2-CH(2)NOMe(2))(3)PO (2) was obtained from 1 by oxidation with hydrogen peroxide. X-ray analysis provided molecular structures for 1A, 1B(1), 1B(2), and 2. Phosphanes 1A and 1B(1) have pseudohexacoordinate frameworks as a result of the formation of two P-N donor interactions, 1B(2) has a pseudoheptacoordinate geometry due to the presence of three P-N interactions, and 2 resides in a tetrahedral geometry. The presence of the flexible dimethylaminobenzyl group in 1A, 1C, 1B(1), and 1B(2) is reasoned to be responsible for this variation in coordination geometry. Phosphane oxide 2 has very strong donor oxygen atoms from N-oxide groups but they are involved in competition with the presence of hydrogen bonding, which results in the lack of donor coordination. High-resolution (1)H, (13)C, and (31)P NMR measurements are also reported. The results provide evidence for the low-energy threshold required to allow hypercoordinated phosphorus to alter coordination geometry.
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Affiliation(s)
- A Chandrasekaran
- Department of Chemistry, University of Massachusetts, Amherst, MA 01003-9336, USA
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Gavrilov K, Bondarev O, Lebedev R, Polosukhin A, Shyryaev A, Lyubimov S, Petrovskii P, Moiseev S, Kalinin V, Ikonnikov N, Davankov V, Korostylev A. New amino-, imino- and oxazolinophosphites based on 1,1′-bi-2-naphtol: coordination and catalytic properties. J Organomet Chem 2002. [DOI: 10.1016/s0022-328x(02)01561-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Gavrilov K, Bondarev O, Lebedev R, Shiryaev A, Lyubimov S, Polosukhin A, Grintselev-Knyazev G, Lyssenko K, Moiseev S, Ikonnikov N, Kalinin V, Davankov V, Korostylev A, Gais HJ. Easily Accessible ChiralP,N-Bidentate Aryl Phosphites, Their Complexation and Application in Enantioselective Allylic Alkylation, Sulfonylation and Hydrosilylation. Eur J Inorg Chem 2002. [DOI: 10.1002/1099-0682(200206)2002:6<1367::aid-ejic1367>3.0.co;2-f] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Abstract
The narcotic drug methohexital 1 contains two asymmetric carbon atoms and, thus, consists of four isomers, two diastereomeric pairs of enantiomers. The commercial drug is the so-called alpha-racemate, one pair of diastereomers only. A method was developed to prepare differently enriched mixtures of methohexital isomers without resorting to lengthy and expensive optical resolutions. A model reaction for the synthesis of methohexital is the palladium-catalyzed allylation of 1,5-dimethyl-barbituric acid 3, which is optimized and checked by molecular modeling. Catalysts with the best ligands are used in the allylation of the methohexital precursor 7, which contains the C(6) sidechain at the tetrahedral center of the barbiturate skeleton. The product stereochemistry was determined by the contribution of the enantioselective Pd catalysts and by the fact that the allylation is a kinetic resolution. The methohexital isomer mixtures obtained were evaluated with the corneal stimulus test of rats. Methohexital compositions were found, which are superior to the commercially used alpha-racemate (Brevimytal).
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Affiliation(s)
- H Brunner
- Institut für Anorganische Chemie, Universität Regensburg, 93040 Regensburg, Germany.
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27
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Polosukhin AI, Bondarev OG, Lyubimov SE, Korostylev AV, Lyssenko KA, Davankov VA, Gavrilov KN. New chiral phosphite ligands bearing sp2-nitrogen: complexation properties and palladium(II)-catalysed enantioselective allylic alkylation. ACTA ACUST UNITED AC 2001. [DOI: 10.1016/s0957-4166(01)00382-2] [Citation(s) in RCA: 28] [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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28
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Komarov IV, Börner A. Highly Enantioselective or Not?-Chiral Monodentate Monophosphorus Ligands in the Asymmetric Hydrogenation. Angew Chem Int Ed Engl 2001; 40:1197-1200. [PMID: 11301424 DOI: 10.1002/1521-3773(20010401)40:7<1197::aid-anie1197>3.0.co;2-g] [Citation(s) in RCA: 133] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Igor V. Komarov
- Institut für Organische Katalyseforschung an der Universität Rostock e.V. Buchbinderstrasse 5/6, 18055 Rostock (Germany)
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29
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Komarov IV, Börner A. Hochenantioselektiv oder nicht? - Chirale einzähnige Monophosphorliganden in der asymmetrischen Hydrierung. Angew Chem Int Ed Engl 2001. [DOI: 10.1002/1521-3757(20010401)113:7<1237::aid-ange1237>3.0.co;2-z] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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30
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Gavrilov KN, Polosukhin AI, Bondarev OG, Korostylev AV, Lyubimov SE, Shiryaev AA, Starikova ZA, Davankov VA. Iminophosphites as new chiral P,N-bidentate ligands. MENDELEEV COMMUNICATIONS 2001. [DOI: 10.1070/mc2001v011n01abeh001356] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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31
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Trost BM, Schroeder GM. Palladium-catalyzed asymmetric allylic alkylation of barbituric acid derivatives: enantioselective syntheses of cyclopentobarbital and pentobarbital. J Org Chem 2000; 65:1569-73. [PMID: 10814127 DOI: 10.1021/jo991491c] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- B M Trost
- Department of Chemistry, Stanford University, Stanford, California 94305-5080, USA
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