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Concise and Free-Metal Access to Lactone-Annelated Pyrrolo[2,1- a]isoquinoline Derivatives via a 1,2-Rearrangement Step. Int J Mol Sci 2024; 25:1085. [PMID: 38256158 PMCID: PMC10816086 DOI: 10.3390/ijms25021085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/24/2024] Open
Abstract
Here, An efficient approach to obtaining previously unknown furo[2',3':2,3]pyrrolo[2,1-a]isoquinoline derivatives from readily available 1-R-1-ethynyl-2-vinylisoquinolines is described. The reaction features a simple procedure, occurs in hexaflouroisopropanol and does not require elevated temperatures. It has been found that the addition of glacial acetic acid significantly increases the yields of the target spirolactone products. Using trifluoroethanol instead of hexaflouroisopropanol results in the formation of pyrido[2,1-a]isoquinolines.
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Divergent and Nucleophile-Assisted Rearrangement in the Construction of Pyrrolo[2,1-b][3]benzazepine and Pyrido[2,1-a]isoquinoline Scaffolds. Chemistry 2024; 30:e202302919. [PMID: 37864779 DOI: 10.1002/chem.202302919] [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: 09/07/2023] [Revised: 10/12/2023] [Accepted: 10/20/2023] [Indexed: 10/23/2023]
Abstract
Under microwave (MW) irradiation at 150 °C in toluene and in the presence of nucleophiles (DMAP, triphenylphosphine and tetrahydrothiophene) 1-substituted 1-ethynyl-2-vinyldi- and tetrahydroisoquinolines undergo [3,3]-sigmatropic rearrangement providing pyrrolo[2,1-b][3]benzazepines in good yields. The replacement of toluene with acetonitrile directs the rearrangement towards the formation of 7,11b-dihydro-6H-pyrido[2,1-a]isoquinolines.
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Donor-Acceptor Cyclopropane Ring Expansion to 1,2-Dihydronaphthalenes. Access to Bridged Seven-Membered Lactones. Org Lett 2023; 25:7963-7967. [PMID: 37916763 DOI: 10.1021/acs.orglett.3c02846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023]
Abstract
A Lewis-acid-promoted domino ring-opening cyclization of readily available donor-acceptor cyclopropanes with a preinstalled electrophilic center, embedded in a donor group, to functionalized 1,2-dihydronaphthalenes is reported herein. The obtained compounds are transformed to pharmacologically attractive bridged tricyclic esters in a diastereospecific manner.
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Photoredox-Catalyzed Chlorotrifluoromethylation of Arylallenes: Synthesis of a Trifluoromethyl Building Block. Org Lett 2023; 25:438-442. [PMID: 36625635 DOI: 10.1021/acs.orglett.2c04214] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A new class of trifluoromethyl building blocks─2-trifluoromethyl allyl chlorides─have been obtained through a photoredox-catalyzed chlorotrifluoromethylation of aryl allenes. The reaction proceeded in a regio- and stereoselective manner. A trifluoromethylated analog of the flunarizine drug was synthesized.
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Electrochemical Decarbonylative Aminosulfonylation of Alkynes with Sulfinates and N-(Formyl)anilides. Org Lett 2022; 24:9337-9341. [PMID: 36516277 DOI: 10.1021/acs.orglett.2c03985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
An unprecedented electrochemical three-component reaction of phenylacetylene, sulfinate, and N-(formyl)anilide was discovered. The transformation occurs in an undivided cell with a graphite anode and cathode in DMF in the presence of tetrabutylammonium iodide as an electrolyte. The addition of silver(I) oxide and catalytic amounts of iodine facilitated the reaction significantly. The transformation was also carried out under photoredox-catalyzed conditions.
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Synthesis of 1,5-Substituted Pyrrolidin-2-ones from Donor-Acceptor Cyclopropanes and Anilines/Benzylamines. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27238468. [PMID: 36500574 PMCID: PMC9735934 DOI: 10.3390/molecules27238468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 11/16/2022] [Accepted: 11/23/2022] [Indexed: 12/12/2022]
Abstract
We developed a straightforward synthetic route to pharmacologically important 1,5-substituted pyrrolidin-2-ones from donor-acceptor cyclopropanes bearing an ester group as one of the acceptor substituents. This method includes a Lewis acid-catalyzed opening of the donor-acceptor cyclopropane with primary amines (anilines, benzylamines, etc.) to γ-amino esters, followed by in situ lactamization and dealkoxycarbonylation. The reaction has a broad scope of applicability; a variety of substituted anilines, benzylamines, and other primary amines as well as a wide range of donor-acceptor cyclopropanes bearing (hetero)aromatic or alkenyl donor groups and various acceptor substituents can be involved in this transformation. In this process, donor-acceptor cyclopropanes react as 1,4-C,C-dielectrophiles, and amines react as 1,1-dinucleophiles. The resulting di- and trisubstituted pyrrolidin-2-ones can be also used in subsequent chemistry to obtain various nitrogen-containing polycyclic compounds of interest to medicinal chemistry and pharmacology, such as benz[g]indolizidine derivatives.
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Facile synthesis of indolizino[8,7- b]indole and pyrido[1,2- a:3,4- b’]diindole derivatives based on domino reactions of 1-aroyl-3,4-dihydro- β-carbolines. SYNTHETIC COMMUN 2022. [DOI: 10.1080/00397911.2022.2145903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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8
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Chemoselective Divergent Transformations of N-(Propargyl)indole-2-carbonitriles with Nitrogen Nucleophiles: Alkyne Hydroamination or Domino Cyclizations. J Org Chem 2022; 87:13663-13671. [PMID: 36190820 DOI: 10.1021/acs.joc.2c01327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Interactions of N-(propargyl)indole-2-carbonitriles with nitrogen nucleophiles were studied. It was found that lithium hexamethyldisilazane (LiHMDS)-promoted reactions give mixtures of two product types, originating from an initial attack onto carbon-carbon or carbon-nitrogen triple bonds. Performing the reaction at reduced temperature and in the presence of catalytic amounts of LiHMDS delivered alkyne hydroamination products exclusively. On the contrary, the one-pot reaction of N-(propargyl)indole-2-carbonitriles with methanol and LiHMDS on heating, followed by the addition of a nitrogen nucleophile, allowed a selective domino cyclization sequence toward 1-aminopyrazino[1,2-a]indoles. Anilines and nitrogen heterocycles could be employed as N-nucleophiles to obtain products of both types. Moreover, an alternative one-pot route toward a third product type has been developed. When N-(propargyl)indole-2-carbonitrile was first combined with aniline and LiHMDS at reduced temperature, further heating of the in situ generated hydroamination product led to the intramolecular cyclization into 1-imino-2-phenylpyrazino[1,2-a]indoles. Thus, chemodivergent transformations of the same starting material into three compound classes were investigated. The possible reaction routes were studied, and N-(allenyl)indole-2-carbonitrile was identified as the key intermediate. Acyclic and cyclic products exhibit fluorescence emission in the blue to green range.
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Convenient synthesis of endo,endo- and endo,exo-bicyclo[3.3.1]nonane diamines. Tetrahedron 2022. [DOI: 10.1016/j.tet.2022.132828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Annealing-Induced Structural Behavior of Mn Dopant Ions in Calcium Orthovanadate Ca 3(VO 4) 2 Single Crystals. Inorg Chem 2022; 61:7060-7068. [PMID: 35471861 DOI: 10.1021/acs.inorgchem.2c00503] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The crystal and local structures of Czochralski-grown calcium orthovanadate (Ca3(VO4)2) single crystals doped with over-stoichiometric 0.05 wt % Mn2O3 (CVO:0.05Mn) and annealed under different conditions are studied by single-crystal conventional and synchrotron X-ray diffraction, X-ray absorption spectroscopy, and electron paramagnetic resonance for the first time. Bottom (annealing in air) and top (annealing in air and in vacuum) parts of the CVO:0.05Mn crystal differ in the manganese content (higher in the bottom part), formal charge (Mn4+ and Mn(3+δ)+, respectively), and color (orange bottom part; light orange and yellow top parts annealed in air and vacuum, respectively). Manganese ions are located in one (Ca3, distorted two-capped trigonal prism) of five crystallographic Ca sites and have octahedral coordination, which is consistent with crystal-chemical properties of transition-metal ions. The presence of vacancies in one of three V sites is revealed. Formal charge 5+ for vanadium ions is confirmed by X-ray photoelectron spectroscopy. Different colors of CVO:Mn crystals and different formal charges of manganese are explained depending on the growth and post-growth treatment conditions.
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Revealing the peculiar local behavior of manganese and cobalt in diffusion-doped calcium orthovanadate Ca 3(VO 4) 2. Dalton Trans 2022; 51:5673-5686. [PMID: 35322815 DOI: 10.1039/d1dt03799d] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Laser Ca3(VO4)2 single crystals (СVO; space group R3c, Z = 21) with crystallochemical formula Ca118Ca218Ca318Ca46(Ca5 + Са5А)3(V118V218V36)O168 grown by the Czochralski method were doped with Мn2O3 (CVO:Мn2O3) and Сo3O4 (CVO:Co3O4) by high-temperature diffusion annealing. Statistical and local structures were comprehensively studied by single-crystal and powder synchrotron X-ray diffraction and conventional single-crystal X-ray diffraction as well as by X-ray absorption spectroscopy for the first time. The presence of Mn(2+δ)+ ions with a mixed formal charge and Co2+ ions in the Ca2 (monocapped trigonal prism), Ca3 (two-capped trigonal prism), and Ca4 (octahedron) sites was revealed by diffraction methods. The tetrahedral coordination and the coordination intermediate between tetrahedral and octahedral were established for Mn(2+δ)+ and Co2+ ions, respectively. A fundamentally different structural behavior of dopant ions (concentration, formal charge, and coordination environment) in the CVO crystals doped with manganese in the form of Mn2O3 during the crystal growth or by high-temperature diffusion annealing was observed. The relationship between characteristic bands in the absorption, fluorescence, and excitation spectra of CVO:Мn2O3 and CVO:Co3O4 samples and transition metals with specific formal charges is discussed.
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A Facile Approach to Bis(isoxazoles), Promising Ligands of the AMPA Receptor. Molecules 2021; 26:molecules26216411. [PMID: 34770819 PMCID: PMC8588558 DOI: 10.3390/molecules26216411] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 10/14/2021] [Accepted: 10/21/2021] [Indexed: 12/30/2022] Open
Abstract
A convenient synthetic approach to novel functionalized bis(isoxazoles), the promising bivalent ligands of the AMPA receptor, was elaborated. It was based on the heterocyclization reactions of readily available electrophilic alkenes with the tetranitromethane-triethylamine complex. The structural diversity of the synthesized compounds was demonstrated. In the electrophysiological experiments using the patch clamp technique on Purkinje neurons, the compound 1,4-phenylenedi(methylene)bis(5-aminoisoxazole-3-carboxylate) was shown to be highly potent positive modulator of the AMPA receptor, potentiating kainate-induced currents up to 70% at 10−11 M.
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Expanding Stereoelectronic Limits of endo- tet Cyclizations: Synthesis of Benz[ b]azepines from Donor-Acceptor Cyclopropanes. J Am Chem Soc 2021; 143:13952-13961. [PMID: 34406759 DOI: 10.1021/jacs.1c07088] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The importance of intramolecular constraints in cyclic transition-state geometries is especially pronounced in n-endo-tet cyclizations, where the usual backside approach of a nucleophile to the breaking bond is impossible for the rings containing less than eight atoms. Herein, we expand the limits of endo-tet cyclizations and show that donor-acceptor cyclopropanes can provide a seven-membered ring via a genuine 6-endo-tet process. Substrates containing a N-alkyl-N-arylcarbamoyl moiety as an acceptor group undergo Lewis acid-induced cyclization to form tetrahydrobenz[b]azepin-2-ones in high yields. The reaction proceeds with the inversion of the configuration at the electrophilic carbon. In this process, a formally six-membered transition state yields a seven-membered ring as the pre-existing cycle is merged into the forming ring. The stereochemistry of the products can be controlled by the reaction time and by the nature of Lewis acid, opening access to both diastereomers by tuning of the reaction conditions.
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Donor-Acceptor Cyclopropane Ring Opening with 6-Amino-1,3-dimethyluracil and Its Use in Pyrimido[4,5- b]azepines Synthesis. J Org Chem 2021; 86:12300-12308. [PMID: 34382810 DOI: 10.1021/acs.joc.1c01064] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A scandium trifluoromethanesulfonate-catalyzed reaction of donor-acceptor cyclopropanes with 6-amino-1,3-dimethyluracil was found to proceed as three-membered ring opening via nucleophilic attack of the C(5) atom of an ambident nucleophile serving as an enamine equivalent. It was shown that, under basic conditions, the obtained products underwent cyclization to 6,7-dihydro-1H-pyrimido[4,5-b]azepine-2,4,8-triones, an interesting subclass of nucleobase analogues.
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5-Nitroisoxazoles in S NAr reactions: access to polysubstituted isoxazole derivatives. Org Biomol Chem 2021; 19:6447-6454. [PMID: 34236067 DOI: 10.1039/d1ob00816a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
An efficient protocol for the straightforward functionalization of the isoxazole ring via the reactions of aromatic nucleophilic substitution of the nitro group with various nucleophiles has been elaborated. The method features excellent chemical yields, easy operability of the reaction, mild reaction conditions and a broad scope of both 5-nitroisoxazoles and nucleophiles. A synthetic approach to 3,5- and 3,4,5-substituted isoxazoles via the sequential functionalization of the isoxazole ring has been developed based on the excellent regioselectivity of the reaction of 3,5-dinitroisoxazoles with nucleophiles.
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Convenient access to pyrrolidin-3-ylphosphonic acids and tetrahydro-2 H-pyran-3-ylphosphonates with multiple contiguous stereocenters from nonracemic adducts of a Ni(II)-catalyzed Michael reaction. Beilstein J Org Chem 2020; 16:2073-2079. [PMID: 32952723 PMCID: PMC7476589 DOI: 10.3762/bjoc.16.174] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 08/10/2020] [Indexed: 01/20/2023] Open
Abstract
A new synthetic strategy toward nonracemic phosphoryl-substituted pyrrolidines and tetrahydropyranes with three and five contiguous stereocenters is presented. Readily available β-keto phosphonates react with conjugated nitroolefins in the presence of a chiral Ni(II) complex to give nitro keto phosphonates with two stereocenters with excellent enantioselectivity and moderate to high diastereoselectivity. These products were used for a reductive cyclization leading to pyrrolidin-3-ylphosphonic acid and for reactions with aldehydes yielding tetrahydropyranylphosphonates as individual stereoisomers. These nonracemic heterocycles containing phosphoryl moieties are useful for designing new pharmacologically active compounds.
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Microwave-Assisted Synthesis of Fluorescent Pyrido[2,3- b]indolizines from Alkylpyridinium Salts and Enaminones. Molecules 2020; 25:E4059. [PMID: 32899473 PMCID: PMC7570714 DOI: 10.3390/molecules25184059] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Revised: 08/24/2020] [Accepted: 09/03/2020] [Indexed: 11/17/2022] Open
Abstract
Pyridinium ylides are well recognized as dipoles for cycloaddition reactions. In its turn, the microwave-assisted interaction of N-(cyanomethyl)-2-alkylpyridinium salts with enaminones unexpectedly proceeds as a domino sequence of cycloisomerization and cyclocondensation reactions, instead of a 1,3-dipolar cycloaddition. The reaction takes place in the presence of sodium acetate as base and employs benign solvents. The optical properties of the resulting pyrido[2,3-b]indolizines were studied, showing green light emission with high fluorescence quantum yields.
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Synthesis of antiaromatic thiazinoindolizines based on electrophilic cyclizations of indolizine-5-thione. Chem Heterocycl Compd (N Y) 2020. [DOI: 10.1007/s10593-020-02754-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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20
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Transformations of 1-[2-(Adamantan-1-Yl)-2-Hydroxyethyl]-1,2,3,6-Tetrahydropyridines by the Action of Trifluoromethanesulfonic Acid. Chem Heterocycl Compd (N Y) 2020. [DOI: 10.1007/s10593-020-02747-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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A simple synthesis of 2-{2-[(arylmethylidene)amino]-indazol-3-yl}malonate esters. Chem Heterocycl Compd (N Y) 2020. [DOI: 10.1007/s10593-020-02699-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Synthesis of 4-Nitroisoxazoles via NO/NO2-Mediated Heterocyclization of Aryl-Substituted α,β-Unsaturated Ketones. SYNTHESIS-STUTTGART 2020. [DOI: 10.1055/s-0039-1690053] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
A straightforward approach for the synthesis of 4-nitroisoxazoles has been developed via heterocyclization of aryl/hetaryl-substituted α,β-unsaturated ketones upon treatment with tetranitromethane-triethylamine (TNM-TEA) complex or t-BuONO. This strategy features high efficiency and wide substrate tolerance under simple reaction conditions.
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Abstract
A series of soluble epoxide hydrolase (sEH) inhibitors containing 2-fluorophenyl fragment was developed. Inhibition potency of the described compounds ranges from 0.7 to 630.9 nM. 1-(Adamantan-1-ylmethyl)-3-(2-fluorophenyl) urea (3b, IC50 = 0.7 nM) and 1-(adamantan-2-yl)-3-(2-fluorophenyl) urea (3i, IC50 =1.0 nM) were found to be the most potent sEH inhibitors within the described series. Crystal results suggest that potency is probably enhanced by extra hydrogen bond between the fluorine atom and catalytic tyrosine residues.
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Dehydrohalogenation of isomeric 2- and 3-bromomethyl substituted 2,3-dihydrooxazolo[3,2-a]pyridines. MENDELEEV COMMUNICATIONS 2020. [DOI: 10.1016/j.mencom.2020.03.033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
Efficient methods for introducing various substituents into the α-position of ethyl 5-oxohomoadamantyl-4-carboxylate are reported. An unexpected acid-catalysed 1,2-alkyl shift in the series of synthesized α,α-bis-substituted 5-oxohomoadamantanes, and also in the hydroxy derivatives of homoadamantane was found. Such a retropinacol-like rearrangement leads to tetra- or pentacyclic mono- or bis-lactones containing a homoadamantane moiety. This new transformation opens access to the synthesis of previously unknown 2,4-di and 2,3,4-trisubstituted derivatives of homoadamantane. The resulting caged γ-butyro- and δ-valerolactones could be considered as potential synthetic or metabolic precursors of conformationally restricted GABA and δ-aminovaleric acid analogues.
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Aza-Henry and aza-Knoevenagel reactions of nitriles for the synthesis of pyrido[1,2-a]indoles. Chem Commun (Camb) 2020; 56:6527-6530. [DOI: 10.1039/d0cc01652g] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
N-(Propargyl)indole-2-carbonitriles undergo DBU-catalyzed addition of CH-acids to nitriles, followed by cyclization to give 9-aminopyrido[1,2-a]indoles.
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Local structural features and composition of the Bi 4Ge 3O 12:Dy 3+ crystals: effect of doping concentration. CrystEngComm 2020. [DOI: 10.1039/d0ce00729c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Dy3+-doped Bi4Ge3O12 crystals possess different actual compositions and structural behavior of Dy3+ and Bi3+ ions depending on the initial Dy2O3 content.
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Copper( i) halide and palladium( ii) chloride complexes of 4-thioxo[1,3,5]oxadiazocines: synthesis, structure and antibacterial activity. NEW J CHEM 2020. [DOI: 10.1039/c9nj05958j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The first copper(i) and palladium(ii) complexes containing monastrol analogs, 4-thioxo[1,3,5]oxadiazocine derivatives, have been synthesized. The complexes demonstrated significant antibacterial activity in contrast to free heterocyclic thiones.
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Rearrangement of thiazolo[3,2-a]pyrimidines into triazolo[4,3-a]pyrimidines induced by C=N bond reduction. Chem Heterocycl Compd (N Y) 2019. [DOI: 10.1007/s10593-019-02604-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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33
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Synthesis of 3-(pyridine-2-yl)-4,5-dihydro-1H-pyrazole-1-thiocarboxamides and their copper(II) complexes. ARAB J CHEM 2019. [DOI: 10.1016/j.arabjc.2017.01.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Synthesis of non-racemic 4-nitro-2-sulfonylbutan-1-ones via Ni(II)-catalyzed asymmetric Michael reaction of β-ketosulfones. Beilstein J Org Chem 2019; 15:1289-1297. [PMID: 31293677 PMCID: PMC6604683 DOI: 10.3762/bjoc.15.127] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 05/22/2019] [Indexed: 12/21/2022] Open
Abstract
Functionally substituted sulfones with stereogenic centers are valuable reagents in organic synthesis and key motifs in some bioactive compounds. The asymmetric Michael addition of β-ketosulfones to conjugated nitroalkenes in the presence of Ni(II) complexes with various chiral vicinal diamines was studied. This reaction provides convenient access to non-racemic 4-nitro-2-sulfonylbutan-1-ones with two stereocenters with high yield and excellent enantioselectivity (up to 99%). It has been established that the catalytic Michael reaction itself was carried out with high diastereoselectivity, but the Michael adducts may epimerize at the C-2 position at a significant rate. Conditions for the preparation of individual diastereomers were found.
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Enantioselective Copper(II)/Box‐Catalyzed Synthesis of Chiral
β
3
‐Tryptophan Derivatives. ChemCatChem 2019. [DOI: 10.1002/cctc.201900575] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Synthesis of 2,3-diaryl-2,3,4,4а-tetrahydro-5Н-indeno[1,2-c]pyridazin-5-ones. Chem Heterocycl Compd (N Y) 2019. [DOI: 10.1007/s10593-019-02448-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Expanding the Reactivity of Donor-Acceptor Cyclopropanes: Synthesis of Benzannulated Five-Membered Heterocycles via Intramolecular Attack of a Pendant Nucleophilic Group. Org Lett 2018; 20:7947-7952. [PMID: 30517005 DOI: 10.1021/acs.orglett.8b03491] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Lewis-acid-induced domino transformations of donor-acceptor cyclopropanes, possessing a nucleophilic center embedded in a donor group, into functionalized 2,3-dihydrobenzo[ b]furans and 2,3-dihydrobenzo[ b]thiophenes are reported herein. An unusual switch of the electrophilic center in the three-membered ring, from the atom bearing a donor substituent to an unsubstituted carbon atom, was achieved by a judicious choice of Lewis acid, which induces the isomerization of a cyclopropane to an electrophilic alkene, and the length of linker, connecting a nucleophilic moiety and the small ring.
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38
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Nitroalkenes in the Ni(II) Catalyzed AsymmetricMichaelAddition. Convenient Route to the Key Intermediate of Brivaracetam. Helv Chim Acta 2018. [DOI: 10.1002/hlca.201800170] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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39
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40
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X-ray mapping in heterocyclic design. X-ray diffraction study of the derivatives 5-amide-4,6-dimethylpyridone-2. Acta Crystallogr A Found Adv 2018. [DOI: 10.1107/s010876731809952x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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41
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(3+3)-Annulation of Donor-Acceptor Cyclopropanes with Diaziridines. Angew Chem Int Ed Engl 2018; 57:10338-10342. [PMID: 29936708 DOI: 10.1002/anie.201805258] [Citation(s) in RCA: 86] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2018] [Revised: 06/10/2018] [Indexed: 12/11/2022]
Abstract
The first example of (3+3)-annulation of two different three-membered rings is reported herein. Donor-acceptor cyclopropanes in reaction with diaziridines were found to afford perhydropyridazine derivatives in high yields and diastereoselectivity under mild Lewis acid catalysis. The disclosed reaction is applicable for the broad substrate scope and exhibits an excellent functional group tolerance.
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42
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Convenient Au(III)-Catalysed Synthesis of 1-Alkyl-3-diethoxy-phosphoryl-1,2,3,4-tetrahydroisoquinolines. ChemistrySelect 2018. [DOI: 10.1002/slct.201801456] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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43
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Rare‐Earth Complexes with the 5,5′‐Bitetrazolate Ligand – Synthesis, Structure, Luminescence Properties, and Combustion Catalysis. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201701154] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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44
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Convenient approach to polyoxygenated dibenzo[c,e]pyrrolo[1,2-a]azepines from donor–acceptor cyclopropanes. Org Chem Front 2018. [DOI: 10.1039/c8qo00742j] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
A convenient approach to polyoxygenated tetrahydrodibenzo[c,e]pyrrolo[1,2-a]azepines from the donor–acceptor cyclopropanes has been developed.
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45
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Substituent effects on stereoselectivity of dihalocarbene reactions with cyclohexadiene and on the reactivity of bis-dihalocyclopropanes in electrophilic nitrations en route to pyrimidine N-oxides. Org Biomol Chem 2017; 15:9433-9441. [PMID: 29095467 DOI: 10.1039/c7ob02463k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Tricyclic bis-adducts of cyclohexa-1,4-diene with bromofluorocarbene and non-symmetric adducts with both bromofluoro- and dichlorocarbenes were synthesised selectively. The treatment of the bis-adducts with nitrating reagents in acetonitrile affords the products of heterocyclization of a sole dihalogenocyclopropane into 4-fluoropyrimidine N-oxide. The difference in the reactivity of bis-cyclopropanes with different sets of halogen substituents leads to selective heterocyclization of bromofluorocyclopropanes without affecting the dichlorocyclopropane moiety.
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46
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The structure of products of phenacylation and subsequent (re)cyclizations of 3-acetyl-4,6-dimethylpyridin-2(1H)-one according to X-ray structural analysis. Chem Heterocycl Compd (N Y) 2017. [DOI: 10.1007/s10593-017-2161-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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47
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Heterocyclization of gem -dichlorocyclopropanes: “Fine tuning” of reactivity towards nitronium triflate. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.06.047] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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48
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Synthesis and antimitotic activity of novel 5-aminoisoxazoles bearing alkoxyaryl moieties. MENDELEEV COMMUNICATIONS 2017. [DOI: 10.1016/j.mencom.2017.05.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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49
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Reactions of 5-Indolizyl Lithium Compounds with Some Bielectrophiles. MOLECULES (BASEL, SWITZERLAND) 2017; 22:molecules22040661. [PMID: 28425958 PMCID: PMC6154666 DOI: 10.3390/molecules22040661] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 04/09/2017] [Accepted: 04/17/2017] [Indexed: 11/16/2022]
Abstract
Indolizyl-5-lithium anions react with succinic and phtalic anhidrides giving 1,4-keto acids, with oxallyl chloride giving 1,2-diketone, and with ethyl pyruvate giving 1,2-hydroxyacid. However, with α-halocarbonyl compounds, they react in different ways, forming the products of selective bromination at C-5 (with α-bromo ketones and esters of α-bromo acids) and 5-chloroacetyl indolizines.
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50
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Alkoxy base-mediated selective synthesis and new rearrangements of 1,2,4-triazolodipyrimidinones. Tetrahedron Lett 2017. [DOI: 10.1016/j.tetlet.2017.01.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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