1
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Shang S, Willems AV, Chauhan SS. A practical diastereoselective synthesis of (-)-bestatin. J Pept Sci 2018; 24. [PMID: 29430772 DOI: 10.1002/psc.3067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 11/29/2017] [Accepted: 01/09/2018] [Indexed: 11/07/2022]
Abstract
Diastereoselective addition of nitromethane to Boc-D-Phe-H in the presence of sodium hydride in diethyl ether/hexane containing 15-crown-5 and subsequent N,O-protection with 2,2-dimethoxypropane gave trans-oxazolidine in a diastereomeric ratio of >16:1. The oxazolidine was easily separated by column chromatography, which after Nef reaction was coupled to H-Leu-OtBu. The 8-step synthesis afforded (-)-bestatin in an overall yield of 24.7% after deprotection and ion exchange.
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Affiliation(s)
- Suisheng Shang
- Peptides International Inc., 11621 Electron Drive, Louisville, KY, 40299, USA
| | - Andreas V Willems
- Peptides International Inc., 11621 Electron Drive, Louisville, KY, 40299, USA
| | - Satendra S Chauhan
- Peptides International Inc., 11621 Electron Drive, Louisville, KY, 40299, USA
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2
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Mitchell ML, Xu L, Newby ZE, Desai MC. Synthesis of novel HIV-1 protease inhibitors via diastereoselective Henry reaction with nitrocyclopropane. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.01.104] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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3
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Borukhova S, Seeger AD, Noël T, Wang Q, Busch M, Hessel V. Pressure-accelerated azide-alkyne cycloaddition: micro capillary versus autoclave reactor performance. CHEMSUSCHEM 2015; 8:504-512. [PMID: 25522301 DOI: 10.1002/cssc.201403034] [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: 09/22/2014] [Indexed: 06/04/2023]
Abstract
Pressure effects on regioselectivity and yield of cycloaddition reactions have been shown to exist. Nevertheless, high pressure synthetic applications with subsequent benefits in the production of natural products are limited by the general availability of the equipment. In addition, the virtues and limitations of microflow equipment under standard conditions are well established. Herein, we apply novel-process-window (NPWs) principles, such as intensification of intrinsic kinetics of a reaction using high temperature, pressure, and concentration, on azide-alkyne cycloaddition towards synthesis of Rufinamide precursor. We applied three main activation methods (i.e., uncatalyzed batch, uncatalyzed flow, and catalyzed flow) on uncatalyzed and catalyzed azide-alkyne cycloaddition. We compare the performance of two reactors, a specialized autoclave batch reactor for high-pressure operation up to 1800 bar and a capillary flow reactor (up to 400 bar). A differentiated and comprehensive picture is given for the two reactors and the three methods of activation. Reaction speedup and consequent increases in space-time yields is achieved, while the process window for favorable operation to selectively produce Rufinamide precursor in good yields is widened. The best conditions thus determined are applied to several azide-alkyne cycloadditions to widen the scope of the presented methodology.
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Affiliation(s)
- Svetlana Borukhova
- Department of Chemical Engineering and Chemistry, Micro Flow Chemistry and Process Technology, Eindhoven University of Technology, Den Dolech 2, 5612AZ, Eindhoven (The Netherlands)
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4
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Kamimura A, Miyazaki K, Suzuki S, Ishikawa S, Uno H. Total synthesis of ent-calystegine B4 via nitro-Michael/aldol reaction. Org Biomol Chem 2012; 10:4362-6. [DOI: 10.1039/c2ob25386k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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5
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Mei L, Jie C, Yang HB, Ming ZS, Hao Y, Ming TH. Synthesis of (C8H11N)2·Zn(OAc)2, (C8H11N)2·Cu(OAc)2, and (C8H11N)2·CuCl2 complexes and application to the Henry reaction. J STRUCT CHEM+ 2011. [DOI: 10.1134/s0022476611040159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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6
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Arai T, Taneda Y, Endo Y. Formation of multi-stereogenic centers using a catalytic diastereoselective Henry reaction. Chem Commun (Camb) 2010; 46:7936-8. [DOI: 10.1039/c0cc03022h] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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7
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Jammi S, Saha P, Sanyashi S, Sakthivel S, Punniyamurthy T. Chiral binuclear copper(II) catalyzed nitroaldol reaction: scope and mechanism. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.10.009] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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9
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Hili R, Baktharaman S, Yudin AK. Synthesis of Chiral Amines Using α‐Amino Aldehydes. European J Org Chem 2008. [DOI: 10.1002/ejoc.200800604] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Ryan Hili
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada, M5S 3H6
| | - Sivaraj Baktharaman
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada, M5S 3H6
| | - Andrei K. Yudin
- Davenport Research Laboratories, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario, Canada, M5S 3H6
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10
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Benito-López F, Egberink RJ, Reinhoudt DN, Verboom W. High pressure in organic chemistry on the way to miniaturization. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.07.108] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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11
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Lai G, Wang S, Wang Z. Asymmetric Henry reaction catalyzed by a copper tridentate chiral schiff-base complex. ACTA ACUST UNITED AC 2008. [DOI: 10.1016/j.tetasy.2008.06.036] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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12
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Yang L, Powell DR, Klein EL, Grohmann A, Houser RP. Delocalized Mixed-Valence Bi- and Trinuclear Complexes with Short Cu−Cu Bonds. Inorg Chem 2007; 46:6831-3. [PMID: 17636901 DOI: 10.1021/ic7010474] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Two mixed-valence copper complexes were synthesized with ligands N-(2-pyridylmethyl)acetamide (Hpmac) and N,N'-(2-methyl-2-pyridylpropan-1,3-diyl)bis(acetamide) (H2pp(ac)2). Dimer [Cu2(pmac)2]OTf and trimer [Cu3(pp(ac)2)2].NaOTf both contain fully delocalized, mixed-valence Cu(1.5)Cu(1.5) moieties.
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Affiliation(s)
- Lei Yang
- Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, OK 73019, USA
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Chen XM, Tong ML. Solvothermal in situ metal/ligand reactions: a new bridge between coordination chemistry and organic synthetic chemistry. Acc Chem Res 2007; 40:162-70. [PMID: 17309196 DOI: 10.1021/ar068084p] [Citation(s) in RCA: 595] [Impact Index Per Article: 35.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Several important solvothermal (including hydrothermal) in situ metal/ligand reactions and their mechanisms, including dehydrogenative carbon-carbon coupling, hydroxylation of aromatic rings, cycloaddition of organic nitriles with azide and ammonia, transformation of inorganic and organic sulfur, as well as the CuII to CuI reduction, are outlined in this Account. The current progress clearly demonstrates the important potential of such reactions in the crystal engineering of functional coordination compounds and one-pot synthesis of some unusual organic ligands that are inaccessible or not easily obtainable via conventional methods, thereby substantiating our expectation that a new bridge has been created between coordination chemistry and synthetic organic chemistry.
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Affiliation(s)
- Xiao-Ming Chen
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.
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14
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Cheng L, Zhang WX, Ye BH, Lin JB, Chen XM. In Situ Solvothermal Generation of 1,2,4-Triazolates and Related Compounds from Organonitrile and Hydrazine Hydrate: A Mechanism Study. Inorg Chem 2007; 46:1135-43. [PMID: 17291112 DOI: 10.1021/ic061303i] [Citation(s) in RCA: 133] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The facile and effective one-pot solvothermal syntheses of 3,5-disubstituted 1,2,4-triazole and its derivatives (substituted group = alkyl, aryl, and pyridyl) through cyclocondensations of organonitriles and hydrazine hydrate in the absence/presence of metal salts have been established. By control of the solvothermal conditions and/or the addition of counteranions, different intermediates and final products were derived from various organonitriles, in which an intermediate N,N'-bis(picolinamide)azine (H4bpa) has been successfully trapped in its neutral manganese(II) complexes. A systematical study shows that, after the initial formation of 2-pyridylamidrazone from 2-cyanopyridine and hydrazine, two reaction paths are involved in the formation of 1,2,4-triazoles: via the formation of 3,6-bis(2-pyridyl)-1,2-dihydro-1,2,4,5-tetrazine and H4bpa as intermediates. The tetrazine and H4bpa paths are preferred in the absence and presence of metal ions, respectively. In the presence of metal ions, metal ion binding can stabilize the tautomers, enhance the nucleophilic reactivity of the imino C atom, and inhibit the tautomerization of H4bpa, hence leading to the formation of 1,2,4-triazolates or H4bpa in complexed forms. The in situ cyclocondensation reactions of 2-pyridylamidrazone and carboxylate into asymmetric 3,5-disubstituted 1,2,4-triazolates under solvothermal conditions have also been observed for the first time. Crystal structures of the crystalline metal complexes have been obtained, including dinuclear [Mn2(bpt)2Cl2(H2O)2] (1) and [Mn2(bpt)2(SCN)2(H2O)2] (3; Hbpt = 3,5-bis(2-pyridyl)-4H-1,2,4-triazole), tetranuclear [Mn4(H3bpa)2(mpt)4(N3)2].2H2O (5; Hmpt = 3-methyl-5-(2-pyridyl)-1H-1,2,4-triazole), [Mn4(H3bpa)2(pt)4(N3)2].2C2H5OH (6; Hpt = 5-(2-pyridyl)-1H-1,2,4-triazole), and [Mn4(H3bpa)4(SCN)4].2C2H5OH (7), as well as helical [Cu(bpt)] (2). Among them, 7 is the first example of a neutral tetranuclear [2 x 2] grid manganese(II) complex. Both 5 and 7 exhibit antiferromagnetic interactions.
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Affiliation(s)
- Lin Cheng
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China
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15
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Wang J, Zheng SL, Hu S, Zhang YH, Tong ML. New In Situ Cleavage of Both S−S and S−C(sp2) Bonds and Rearrangement Reactions toward the Construction of Copper(I) Cluster-Based Coordination Networks. Inorg Chem 2007; 46:795-800. [PMID: 17257022 DOI: 10.1021/ic0616028] [Citation(s) in RCA: 131] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Solvothermal reaction of 4,4'-dithiodipyridine (dtdp) with CuI at 120 or 160 degrees C results in the formation of three new coordination networks formulated with [Cu4I4(tdp)2] (1; tdp = 4,4'-thiodipyridine), [Cu5I5(ptp)2] (2), and [Cu6I6(ptp)2] [3; ptp = 1-(4-pyridyl)-4-thiopyridine]. The starting dtdp reagent was unprecedentedly converted into two tdp and ptp ligands via new in situ cleavage of both S-S and S-C(sp2) bonds and temperature-dependent in situ ligand rearrangement of dtdp. 1 is a two-dimensional (2D) Cu4I4 cubane-like coordination network of 2-fold interpenetration. While in 2, the Cu8I8 and Cu2I2 cluster units are alternately connected by the mu2-sulfur bridges into one-dimensional inorganic chains along the a axis, which are further joined by the ptp spacers into a three-dimensional (3D) coordination network of 2-fold interpenetration. 3 is a 3D non-interpenetrating coordination network constructed with 2D inorganic (Cu2I2)n layers and the ptp spacers. 1 displays an intense orange-red emission light with a maximum at ca. 563 nm. While luminescence quenching occurs in 2 and 3 by electron transfer of a photoelectron to the electronegative acceptor molecule of ptp.
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Affiliation(s)
- Jing Wang
- MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, State Key Laboratory of Optoelectronic Materials and Technologies, School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China
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17
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18
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Masaoka S, Tanaka D, Kitahata H, Araki S, Matsuda R, Yoshikawa K, Kato K, Takata M, Kitagawa S. Chemical Reaction-Inspired Crystal Growth of a Coordination Polymer toward Morphology Design and Control. J Am Chem Soc 2006; 128:15799-808. [PMID: 17147390 DOI: 10.1021/ja065254k] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This paper reports a novel crystal growth system of a coordination framework {[Cu3(CN)3{hat-(CN)3(OEt)3}]}n (1) (hat-(CN)3(OEt)3 = 2,6,10-tricyano-3,7,11-triethoxy-1,4,5,8,9,12-hexaazatriphenylene). The coordination polymer is crystallized through the reaction of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (hat-(CN)6), ethanol, and copper(I) complex, involving the breaking and forming of covalent bonds. The crystal morphologies obtained in the present system contain dumbbells, cogwheels, and superlattices. Moreover, in the growth perpendicular to the c-axis, periodic ramification at regular interval is observed, affording superlattice morphologies. Observation of the growth of dumbbell crystals shows that the growth rates parallel and perpendicular to the crystallographic c-axis are quite different: the former shows a drastic change with the reaction duration, while the latter is almost constant. These results are reproduced as a simple reaction-diffusion system, indicating that chemical reactions on crystal surfaces play an important role in determining the macroscopic crystal morphologies.
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Affiliation(s)
- Shigeyuki Masaoka
- Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8510, Japan
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19
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Du M, Zhang ZH, Zhao XJ, Xu Q. Modulated Preparation and Structural Diversification of ZnII and CdII Metal−Organic Frameworks with a Versatile Building Block 5-(4-Pyridyl)-1,3,4-oxadiazole-2-thiol. Inorg Chem 2006; 45:5785-92. [PMID: 16841982 DOI: 10.1021/ic060129v] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Four novel Zn(II) and Cd(II) metal-organic coordination polymers with a versatile building block 5-(4-pyridyl)-1,3,4-oxadiazole-2-thiol (Hpyt) have been prepared under different conditions. [Zn3(pyt)4(OH)2]n (1) and [Cd(pyt)(HCOO)]n (3) were obtained through a solvothermal method, whereas {[Zn(pyt)2(H2O)(2)].(DMF)2}n (2) and {[Cd(pyt)2].CHCl3}n (4) were isolated under general conditions. X-ray single-crystal diffraction indicates that the anionic ligand pyt adopts a thioamide isomer in 1, 2, and 4, but a thiolate form in 3. Four types of binding modes involving monodentate (eta-N(oxa)), bidentate (mu-N(py),N(oxa), or mu-N(py),S,S) and tridentate (mu-N(py),N(oxa),S) are observed. The discrepancy of the synthetic routes and metal-coordination preferences facilitates the production of the final crystalline materials with distinct network structures, including a 1D zigzag array of 1 with dangling arms, a common 2D (4,4) coordination layer of 2, a decorated 3D alpha-Po network of 3, and an unprecedented (3,6)-connected 3D framework of 4 with a (4(2).6)2(4(2).6(2).8(7).10(2)) topology. Notably, the hydrolysis of DMF solvates leads to the formation of formate ions, being a component in the structure of 3. Complexes 2 and 4 show 1D channels in which the solvates are accommodated, and even after the exclusion of these guests, the porous host frameworks are still retained. Thermal stability and gas adsorption properties have also been studied.
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Affiliation(s)
- Miao Du
- College of Chemistry and Life Science, Tianjin Normal University, Tianjin 300074, P. R. China.
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20
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Zhang XM, Hao ZM, Wu HS. Cuprophilicity-Induced Cocrystallization of [Cu2(4,4‘-bpy)(CN)2]n Sheets and [Cu(SCN)]n Chains into a 3-D Pseudopolyrotaxane. Inorg Chem 2005; 44:7301-3. [PMID: 16212350 DOI: 10.1021/ic051104j] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cocrystallization of [Cu(SCN)]n chains and [Cu2(4,4'-bpy)(CN)2]n (4,4'-bpy = 4,4'-bipyridine) layers generated a 3-D pseudopolyrotaxane compound, [Cu2(4,4'-bpy)(CN)2].[Cu(SCN)] (1), which can also be viewed as a 3-D network constructed by linkages of 2-D sheets and 1-D chains via unsupported CuI-CuI interactions. The CuI-CuI contact of 2.651(4) A in 1 is the shortest unsupported CuI-CuI distance documented to date, indicating cuprophilic attractions.
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Affiliation(s)
- Xian-Ming Zhang
- School of Chemistry & Material Science, Shanxi Normal University, Linfen 041004, Shanxi, People's Republic of China.
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21
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Matsumoto K, Kim J, Iida H, Hamana H, Kumamoto K, Kotsuki H, Jenner G. MulticomponentStrecker Reaction under High Pressure. Helv Chim Acta 2005. [DOI: 10.1002/hlca.200590136] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Zhang XM, Fang RQ, Wu HS. A Twelve-Connected Cu6S4 Cluster-Based Coordination Polymer. J Am Chem Soc 2005; 127:7670-1. [PMID: 15913344 DOI: 10.1021/ja050284t] [Citation(s) in RCA: 243] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Hydrothermal reaction of Cu(MeCO2)2, (4-pyridylthio)acetic acid, and NH4SCN resulted in a metal-organic framework [Cu3(4-pyridinethiolate)2(CN)] which has twelve-connected face-centered cubic topology with Cu6S4 clusters as nodes.
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Affiliation(s)
- Xian-Ming Zhang
- School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004, Shanxi, PR China.
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23
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Zhang JP, Lin YY, Huang XC, Chen XM. Well-Resolved, New Water Morphologies Obtained by Modification of the Hydrophilic/Hydrophobic Character and Shapes of the Supporting Layers. Inorg Chem 2005; 44:3146-50. [PMID: 15847420 DOI: 10.1021/ic0483186] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The planar coordination complexes [Ag2L2] (L = ophen or obpy, where Hophen = 1H-[1,10]phenanthrolin-2-one and Hobpy = 1H-[2,2']bipyridinyl-6-one) contain both hydrophilic and hydrophobic functional groups. Crystallization of these structurally related complexes in an aqueous medium gives [Ag2(ophen)2]2 x 6H2O (1), [Ag2(obpy)2]3 x 18H2O (2), and [Ag2(obpy)2]2 x 14.5H2O (3). Novel water morphologies are observed in these crystalline hydrates, similar 2D metal-organic layers in which the planar [Ag2L2] complexes as building blocks are stacked alternately together and provide hydrogen bond acceptor sites (O atoms) for anchoring 1D water chains or 2D water layers on their surfaces. In the wavelike metal-organic framework of 1, the wide hydrophobic region renders the formation of 1D water tapes containing four- and six-membered water rings, whereas more complex 2D water layers are sandwiched in 2 and 3, owing to the fact that the surfaces of the supporting layers are more hydrophilic than 1.
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Affiliation(s)
- Jie-Peng Zhang
- School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, People's Republic of China
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Zhang JP, Lin YY, Huang XC, Chen XM. Copper(I) 1,2,4-Triazolates and Related Complexes: Studies of the Solvothermal Ligand Reactions, Network Topologies, and Photoluminescence Properties. J Am Chem Soc 2005; 127:5495-506. [PMID: 15826187 DOI: 10.1021/ja042222t] [Citation(s) in RCA: 494] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
One-pot solvothermal treatments of organonitriles, ammonia, and Cu(II) salts yielded Cu(I) and 3,5-disubstituted 1,2,4-triazolates. The organic triazolate components were derived from copper-mediated oxidative cycloaddition of nitriles and ammonia, in which a key intermediate 1,3,5-triazapentadienate was isolated as [Cu(II)(4-pytap)(2)] (4-Hpytap = 2,4-di(4-pyridyl)-1,3,5-triazapentadiene) via controlled solvothermal conditions. This intermediate could also be synthesized by Ni(II)-mediated reactions; however, the final triazoles were obtained only when Cu(II) was employed. Therefore, the reaction mechanism of these reactions was elucidated as follows: nitrile was first attacked by ammonia to form the amidine, which further reacted with another nitrile or self-condensed to yield 1,3,5-triazapentadiene, which was coordinated to two Cu(II) ions in its deprotonated form. A two-electron oxidation of the 1,3,5-triazapentadienate mediated by two Cu(II) ions gave one triazolate and Cu(I) cations. Other in situ ligand reactions, such as C-C bond cleavage and hydrolysis, were also found for the nitriles under these solvothermal conditions. Another remarkable feature of these crystalline Cu(I) triazolates is their simple, typical 3- or 4-connected network topologies. The self-assembly of these nets is presumably controlled by steric hindrance, which is subsequently applied to the rational design of the close-packed 2D networks [Cu(I)(tz)](infinity) and [Ag(I)(tz)](infinity) (Htz = 1,2,4-triazole), as well as the porous 3D network [Cu(I)(etz)](infinity) (Hetz = 3,5-diethyl-1,2,4-triazole). The interesting photoluminescence properties of these coinage d(10) metal complexes were also investigated.
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Affiliation(s)
- Jie-Peng Zhang
- School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China
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25
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Palomo C, Oiarbide M, Mielgo A. Unveiling Reliable Catalysts for the Asymmetric Nitroaldol (Henry) Reaction. Angew Chem Int Ed Engl 2004; 43:5442-4. [PMID: 15455452 DOI: 10.1002/anie.200460506] [Citation(s) in RCA: 265] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Claudio Palomo
- Departamento de Química Orgánica I, Facultad de Química, Universidad del País Vasco, Apdo. 1072, 20080 San Sebastián, Spain.
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26
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Palomo C, Oiarbide M, Mielgo A. Verbesserte Katalysatoren für die asymmetrische Nitroaldol-Reaktion (Henry-Reaktion). Angew Chem Int Ed Engl 2004. [DOI: 10.1002/ange.200460506] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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27
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Yasuhara T, Osafune E, Nishimura K, Yamashita M, Yamada KI, Muraoka O, Tomioka K. Efficient synthesis of (±)-γ-lycorane employing stereoselective conjugate addition to nitroolefin. Tetrahedron Lett 2004. [DOI: 10.1016/j.tetlet.2004.02.096] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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28
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Pan Q, Zou B, Wang Y, Ma D. Diastereoselective Aldol Reaction of N,N-Dibenzyl-α-amino Aldehydes with Ketones Catalyzed by Proline. Org Lett 2004; 6:1009-12. [PMID: 15012087 DOI: 10.1021/ol049927k] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] L-proline-catalyzed direct aldol reaction of L-amino acid-derived N,N-dibenzyl amino aldehydes with acetone, cyclopentanone, or hydroxyacetone provides gamma-amino-beta-hydroxy- or gamma-amino-alpha,beta-dihydroxy-ketones with moderate to excellent yields and diastereoselectivities.
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Affiliation(s)
- Qiangbiao Pan
- Department of Chemistry, Fudan University, Shanghai 200433, China
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Zheng SL, Zhang JP, Wong WT, Chen XM. A novel, highly electrical conducting, single-component molecular material: [Ag2(ophen)2] (Hophen = 1H-[1,10]phenanthrolin-2-one). J Am Chem Soc 2003; 125:6882-3. [PMID: 12783537 DOI: 10.1021/ja029097a] [Citation(s) in RCA: 209] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This communication describes a highly conducting, single-component molecular material [Ag2(ophen)2] (Hophen = 1H-[1,10]phenanthrolin-2-one) based on very strong off-set pi-pi stacking interactions with an unusually short ring-to-ring distance of ca. 3.15 A between adjacent molecules and silver(I)-pi interactions with the Ag...C contact of 3.082 A between adjacent molecules. The title compound, having a room-temperature conductivity of 14 S cm-1, is structurally different from both the known conducting single-component molecular materials of transition-metal complexes with sulfur-containing pi-delocalized dithiolene ligands and the known conducting multicomponent organosilver(I) materials.
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Affiliation(s)
- Shao-Liang Zheng
- School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, P. R. China
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30
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Crich D, Ranganathan K, Rumthao S, Shirai M. Asymmetric synthesis of highly substituted beta-nitro alcohols and enantiomerically enriched 4,4,5-trisubstituted oxazolidinones. J Org Chem 2003; 68:2034-7. [PMID: 12608832 DOI: 10.1021/jo026707g] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
It is demonstrated that alpha,alpha-disubstituted-alpha-nitroketones are reduced to the corresponding trisubstituted nitro alcohols in good to excellent yield and enantiomeric excess by borane-dimethyl sulfide in the presence of a chiral oxazaborolidine catalyst. Reduction of the nitro alcohols to the corresponding amino alcohols and their subsequent conversion to enantiomerically enriched 4,4,5-trisubstituted oxazoldinones is also reported.
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Affiliation(s)
- David Crich
- Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, Illinois 60607-7061, USA.
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31
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Ma D, Pan Q, Han F. Diastereoselective Henry reactions of N,N-dibenzyl α-amino aldehydes with nitromethane catalyzed by enantiopure guanidines. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)02332-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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32
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Gupta R, Zhang ZH, Powell D, Hendrich MP, Borovik AS. Synthesis and characterization of completely delocalized mixed-valent dicopper complexes. Inorg Chem 2002; 41:5100-6. [PMID: 12354043 DOI: 10.1021/ic0202918] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The multidentate ligands tris[(N'-tert-butylureayl)-N-ethyl)]amine (H(6)1) and 1-(tert-butylaminocarbonyl)-2,2-dimethylaminoethane (H(2)2) have been used to investigate the assembly and properties of complexes with Cu(1.5)Cu(1.5) units. The complexes [Cu(H(5)1)](2)(+) and [Cu(H2)](2)(+) have been isolated and structurally characterized by X-ray diffraction methods. [Cu(H(5)1)](2)(+) has a Cu(1.5)Cu(1.5) core, with each copper ion having square planar coordination geometry. The copper ions are linked through two mono-deprotonated urea ligands, which coordinate as mu-1,3-(kappaN:kappaO) ureate bridges to produce a Cu-Cu distance of 2.39 A. The remaining two urea arms of [H(5)1](-) form intramolecular hydrogen bonds, the result of which is to confine the Cu(1.5)Cu(1.5) unit within a pseudomacrocycle. The structure of [Cu(H2)](2)(+) lacks intramolecular hydrogen bonds and thus does not have a pseudomacrocyclic structure. However, the structural properties of the Cu(1.5)Cu(1.5) core in [Cu(H2)](2)(+) are nearly identical to those of [Cu(H(5)1)](2)(+). Both complexes exhibit rhombic EPR spectra at 77 K, which do not change upon cooling to 4 K. The optical spectra of [Cu(H(5)1)](2)(+) and [Cu(H2)](2)(+) are dominated by an intense band at approximately 700 nm. These spectral characteristics are consistent with [Cu(H(5)1)](2)(+) and [Cu(H2)](2)(+) being classified as fully delocalized (type III) mixed-valent species.
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Affiliation(s)
- Rajeev Gupta
- Departments of Chemistry, University of Kansas, Lawrence, KS 66045, USA
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