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Search for "biological properties" in Full Text gives 203 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Partial thioamide scan on the lipopeptaibiotic trichogin GA IV. Effects on folding and bioactivity
- Marta De Zotti,
- Barbara Biondi,
- Cristina Peggion,
- Matteo De Poli,
- Haleh Fathi,
- Simona Oancea,
- Claudio Toniolo and
- Fernando Formaggio
Beilstein J. Org. Chem. 2012, 8, 1161–1171, doi:10.3762/bjoc.8.129
- -terminal 1,2-amino alcohol leucinol (Lol) by the corresponding α-amino methyl ester (Leu-OMe) alters only slightly the biophysical and biological properties of trichogin GA IV. Conversely, we showed that the Nα-blocking fatty acyl moiety plays a major role in its membrane permeability and antibiotic
Graphical Abstract
Figure 1: List of primary structures and abbreviations for the peptides studied in this work. The [Leu11-OMe]...
Scheme 1: Synthesis of ψ[CS-NH]2. 1: Coupling in the presence of EDC/HOBt. 2: Deprotection by using TFA/DCM. ...
Scheme 2: Synthesis of ψ[CS-NH]5. 1: Coupling in the presence of EDC/HOBt. 2: Deprotection by using TFA/DCM. ...
Scheme 3: Synthesis of ψ[CS-NH]9. 1: Deprotection by catalytic hydrogenation with Pd/C. 2: Coupling with n-Oc...
Figure 2: RP-HPLC profiles obtained for [Leu11-OMe] trichogin GA IV (tric-OMe) and its ψ[CS-NH]2, ψ[CS-NH]5, ...
Figure 3: Far-UV (panel I) and near-UV (panel II) CD spectra of [Leu11-OMe] trichogin GA IV (tric-OMe) and it...
Figure 4: FT-IR absorption spectra (3550–3200 cm−1 region) in CDCl3 solution of [Leu11-OMe] trichogin GA IV (...
Figure 5: Region of the amide NH protons in the H/H-ROESY spectrum of ψ[CS-NH]9 (400 MHz, 1 mM in CD3CN solut...
Figure 6: Fingerprint region of the H/H-ROESY spectrum of ψ[CS-NH]9 (400 MHz, 1 mM in CD3CN solution, 298 K)....
Figure 7: Fingerprint region of the H/H-ROESY spectrum of ψ[CS-NH]9 (400 MHz, 1 mM in CD3CN solution, 298 K)....
Figure 8: Ribbon representation of the lowest energy (138.7 kcal/mol) 3D structure obtained for ψ[CS-NH]9. Al...
Synthesis of a library of tricyclic azepinoisoindolinones
- Bettina Miller,
- Shuli Mao,
- Kara M. George Rosenker,
- Joshua G. Pierce and
- Peter Wipf
Beilstein J. Org. Chem. 2012, 8, 1091–1097, doi:10.3762/bjoc.8.120
- heterocycles have demonstrated a variety of pharmacological activities, including anti-inflammatory [5], antihypertensive [6] and vasodilatory [7], antipsychotic [8][9], and anticancer effects [10]. Due to the broad biological properties and the general utility of isoindolinones in the preparation of other
Graphical Abstract
Figure 1: Representative isoindolinone natural products and pharmaceuticals.
Scheme 1: Formation of isomerized azepinoisoindoline 3 and oxirane 5.
Figure 2: X-Ray structure of epoxide 5.
Figure 3: Relative energies of alkene isomers based on RB3LYP/6-311G* calculations with MacSpartan ’06.
Scheme 2: Ring-closing metathesis of diene 2 in the absence of Ti(OiPr)4 and isolation of hydroxy epoxide 6 a...
Figure 4: X-Ray structure of epoxyalcohol 6.
Scheme 3: Preparation and RCM reaction of bis-terminal diene analogue 7.
Scheme 4: Conversion of epoxide 5 to 1,2-amino alcohols.
Figure 5: Amine building blocks for library synthesis.
Figure 6: X-ray structure of amino alcohol 10{7}.
Synthesis and in silico screening of a library of β-carboline-containing compounds
- Kay M. Brummond,
- John R. Goodell,
- Matthew G. LaPorte,
- Lirong Wang and
- Xiang-Qun Xie
Beilstein J. Org. Chem. 2012, 8, 1048–1058, doi:10.3762/bjoc.8.117
- pyrazole group of 6{10}. Ligand-based strategy for target prediction Ligand-based target prediction algorithms have been developed based upon an established medicinal chemistry principle that structurally similar compounds, with comparable physical properties, should convey related biological properties
Graphical Abstract
Figure 1: Tetrahydro-β-carboline containing scaffolds 1–3.
Figure 2: Library of tetrahydro-β-carboline containing compounds 1–7 and calculated properties (amolecular we...
Figure 3: Results of high-throughput docking analysis. Top: A docking-score matrix arranged by compound IDs a...
Synthesis and characterization of new diiodocoumarin derivatives with promising antimicrobial activities
- Hany M. Mohamed,
- Ashraf H. F. Abd EL-Wahab,
- Ahmed M. EL-Agrody,
- Ahmed H. Bedair,
- Fathy A. Eid,
- Mostafa M. Khafagy and
- Kamal A. Abd-EL-Rehem
Beilstein J. Org. Chem. 2011, 7, 1688–1696, doi:10.3762/bjoc.7.199
- their antidepressant, antithrombotic, antipsychotic (for the central nervous system, CNS) and anti-breast-cancer activities [13]. In view of the important biological properties of the diiodocoumarin derivatives and iodo-organic compounds as medical agents, we planned to synthesize some new
- diiodocoumarin derivatives bearing side chains with different structures, as such derivatives could possess interesting and useful biological properties. Results and Discussion Interaction of 3,5-diiodosalicylaldehyde with diethyl malonate according to the literature procedure [14][15] afforded ethyl 6,8
Graphical Abstract
Scheme 1: Synthesis of 6,8-diiodocoumarin derivatives 1–7.
Scheme 2: Proposed fragmentation pathways for the EI ions of the substituted 6,8-diiodocoumarins 3 and 7.
Scheme 3: Synthesis of 6,8-diiodocoumarin-3-N-carboxamide derivatives 8–11.
Scheme 4: Synthesis of ethyl cyanoacetate and pyridine derivatives 12 and 13.
Scheme 5: Synthesis of 1,3-oxazocine derivatives 14a,b.
Figure 1: Graphical representation of the antibacterial activity of tested compounds compared to ampicillin.
Figure 2: Graphical representation of antifungal activity of tested compounds, compared to calforan.
A novel and facile synthesis of 3-(2-benzofuroyl)- and 3,6-bis(2-benzofuroyl)carbazole derivatives
- Wentao Gao,
- Meiru Zheng and
- Yang Li
Beilstein J. Org. Chem. 2011, 7, 1533–1540, doi:10.3762/bjoc.7.180
- substituted with a carbazole unit. Hence the synthesis of such compounds is desirable [29][30]. On the other hand, the benzofuran derivatives are an important class of heterocyclic compounds that are known to possess important biological properties [31][32][33]. Especially, recent studies have shown that some
- benzofuroyl-based compounds display important biological properties as antimicrobial [34], anticonvulsant, anti-inflammatory [35], anti-tumor [36], and antifungal [37][38] activities. On account of these findings, extensive synthetic efforts have been devoted to the development of more novel and interesting
Graphical Abstract
Scheme 1: PEG-400 catalyzed ultrasound-assisted Rap–Stoermer synthesis of 3-(2-benzofuroyl)carbazoles 3a–k.
Scheme 2: Synthesis of naphtho[2,1-b]furoyl-N-ethyl-9H-carbazole 3l and 5l.
Synthesis of (−)-julocrotine and a diversity oriented Ugi-approach to analogues and probes
- Ricardo A. W. Neves Filho,
- Bernhard Westermann and
- Ludger A. Wessjohann
Beilstein J. Org. Chem. 2011, 7, 1504–1507, doi:10.3762/bjoc.7.175
- ]. In addition, the glutarimide motif can be considered as a privileged structure. Compounds with this pharmacophore often exhibit a wide range of biological properties including anti-inflammatory [10], antitumor [11][12], and anticonvulsive properties [13]. Because of the low yields of julocrotine
Graphical Abstract
Figure 1: Retrosynthetic scheme for (−)-julocrotine (1).
Scheme 1: Reactions and conditions: (a) DCC, NHS, DMF 80 °C, 18 h, 76%. (b) Ph(CH2)2Br, K2CO3, acetone, r.t.,...
Scheme 2: Reactions and conditions: (a) (CH2O)n, MeOH, r.t., 2 h then, RCOOH and t-BuNC, r.t., 18 h.
Scheme 3: Reactions and conditions: (a) (CH2O)n, MeOH, r.t., 2 h then, (S)-2-methylbutanoic acid and 7, r.t. ...
Directed aromatic functionalization in natural-product synthesis: Fredericamycin A, nothapodytine B, and topopyrones B and D
- Charles Dylan Turner and
- Marco A. Ciufolini
Beilstein J. Org. Chem. 2011, 7, 1475–1485, doi:10.3762/bjoc.7.171
- of topoisomerases, which are overexpressed in cancerous cells, is fatal to the cell [92]. Subsequent studies revealed that topopyrones are in fact dual inhibitors of topo-I and topo-II [93]: A finding that diminished the biomedical relevance of the natural products. Regardless, the biological
- properties of topopyrones are sufficiently interesting that a number of groups embarked on a total synthesis [94][95][96]. Our own involvement in this area was motivated by an interest in topoisomerase-I inhibitors, which are important antineoplastic resources [97], the archetype of which is camptothecin [81
Graphical Abstract
Scheme 1: Structure and retrosynthetic analysis of fredericamycin A.
Scheme 2: Assembly of the isoquinolone segment of fredericamycin.
Scheme 3: Synthesis of a naphthalide precursor to the quinoid moiety of fredericamycin.
Scheme 4: Palladium-mediated cyclization of a fredericamycin model system.
Scheme 5: Synthesis of the precursor of fredericamycin and the facile air oxidation thereof.
Scheme 6: Formal synthesis of fredericamycin A.
Figure 1: Structure of nothapodytine B.
Scheme 7: A useful pyridone synthesis.
Scheme 8: Retrosynthetic logic for nothapodytine B.
Scheme 9: Preparation of a key nothapodytine fragment.
Scheme 10: Total synthesis of nothapodytine B.
Figure 2: Structures of topopyrones.
Scheme 11: Retrosynthetic logic for the linear series of topopyrones.
Scheme 12: Construction of the molecular subunit common to all topopyrones.
Scheme 13: Difficulties encountered during the merger of the topopyrone D moieties.
Scheme 14: Efficient synthesis of a simplified anthraquinone.
Scheme 15: Total synthesis of topopyrone D.
Scheme 16: Total synthesis of topopyrone B.
Selectivity in C-alkylation of dianions of protected 6-methyluridine
- Ngoc Hoa Nguyen,
- Christophe Len,
- Anne-Sophie Castanet and
- Jacques Mortier
Beilstein J. Org. Chem. 2011, 7, 1228–1233, doi:10.3762/bjoc.7.143
- . Whereas direct ring alkylation of 6-lithiated uridine 11 with ω-alkenyl bromides failed, our approach relies on lateral lithiation/alkylation of 6-methyluridine 2. The total synthesis and biological properties of cyclonucleosides 5 will be reported separately. Lithiation of 2',3'-O-isopropylideneuridine
Graphical Abstract
Scheme 1: Synthesis of potent antiviral and antitumor cyclonucleosides 5.
Figure 1: Lithiation of 2',3'-O-isopropylideneuridine (6).
Figure 2: Metalation of 5'-O-TMDMS protected nucleoside 10.
Figure 3: Lithiation/alkylation of 2',3',5'-tri-O-benzoyl-3,6-dimethyluridine (13) using LDA.
Scheme 2: Preparation of 2',3'-O-isopropylidene-5'-O-(tert-butyldimethylsilyl)-6-methyluridine (2).
Scheme 3: Lateral lithiation/alkylation of 6-methyluridine 2.
Figure 4: Bis-allylated products 20 and 21.
A simple and convenient one-pot synthesis of substituted isoindolin-1-ones via lithiation, substitution and cyclization of N'-benzyl-N,N-dimethylureas
- Keith Smith,
- Gamal A. El-Hiti,
- Amany S. Hegazy and
- Benson Kariuki
Beilstein J. Org. Chem. 2011, 7, 1219–1227, doi:10.3762/bjoc.7.142
- ]. Also, some members that possess this moiety have shown interesting biological properties [9][10][11][12][13][14][15]. Several traditional methods are available for the synthesis of isoindolinones [16][17][18][19][20][21][22][23][24][25], based on the use of Grignard reagents [26], Diels–Alder reactions
Graphical Abstract
Scheme 1: Lithiation and substitution of isoindolin-1-ones [43].
Scheme 2: Lithiation and cyclization of N-tert-butyl-N-benzylbenzamides [45].
Scheme 3: Lithiation and substitution of 1 at −20 °C [69].
Figure 1: Structures of 4–6.
Scheme 4: A possible mechanism for the formation of 6.
Figure 2: X-Ray crystal structures of crystallized compounds 12 and 15–18.
Figure 3: Structures of compounds 41–44.
Figure 4: X-ray crystal structures of compounds 38 and 39.
Novel synthesis of pseudopeptides bearing a difluoromethyl group by Ugi reaction and desulfanylation
- Jingjing Wu,
- Hui Li and
- Song Cao
Beilstein J. Org. Chem. 2011, 7, 1070–1074, doi:10.3762/bjoc.7.123
- often drastically alters the chemical, physical, and biological properties of the parent compounds [6][7][8][9]. Nowadays, difluoromethyl-containing compounds are increasingly being applied in pharmaceuticals and agrochemicals [10][11][12]. It is reported that difluoromethyl functionality (CF2H) is
Graphical Abstract
Figure 1: Two examples of bioactive pseudopeptides bearing a CF2H group.
Scheme 1: Synthesis of difluoromethyl-containing pseudopeptides (4a–m) by Ugi reaction and desulfanylation.
Scheme 2: The Ugi reaction of aniline, benzaldehyde, (isocyanomethyl)benzene with acetic acid, difluoroacetic...
Scheme 3: Synthesis of 2,2-difluoro-2-(phenylthio)acetic acid (2).
Approaches towards the synthesis of 5-aminopyrazoles
- Ranjana Aggarwal,
- Vinod Kumar,
- Rajiv Kumar and
- Shiv P. Singh
Beilstein J. Org. Chem. 2011, 7, 179–197, doi:10.3762/bjoc.7.25
- properties of 5-aminopyrazoles have prompted enormous research aimed at developing synthetic routes to these heterocyles. This review focuses on the biological properties associated with this system. Various synthetic methods developed up to 2010 for these compounds are described, particularly those that
Graphical Abstract
Figure 1: Pharmacologically active 5-aminopyrazoles.
Scheme 1: General equation for the condensation of β-ketonitriles with hydrazines.
Scheme 2: Reaction of hydrazinoheterocycles with α-phenyl-β-cyanoketones (4).
Scheme 3: Condensation of cyanoacetaldehyde (7) with hydrazines.
Scheme 4: Synthesis of 5-aminopyrazoles and their sulfonamide derivatives.
Scheme 5: Synthesis of 5-aminopyrazoles, containing a cyclohexylmethyl- or phenylmethyl- sulfonamido group at...
Scheme 6: Regioselective synthesis of 3-amino-2-alkyl (or aryl) thieno[3,4-c]pyrazoles 19.
Scheme 7: Solid supported synthesis of 5-aminopyrazoles.
Scheme 8: Synthesis of 5-aminopyrazoles from resin supported enamine nitrile 25 as the starting material.
Scheme 9: Two-step “catch and release” solid-phase synthesis of 3,4,5-trisubstituted pyrazoles.
Scheme 10: Synthesis of pyrazolo[5,1-d][1,2,3,5]tetrazine-4(3H)-ones.
Scheme 11: Synthesis of the 5,5-ring system, imidazo[1,2-b]pyrazol-2-ones.
Scheme 12: Synthesis of 5-amino-3-(pyrrol-2-yl)pyrazole-4-carbonitrile.
Scheme 13: Synthesis of N-(1,3-diaryl-1H-pyrazol-5-yl)benzamide.
Scheme 14: Synthesis of 3,7-bis(arylazo)-6-methyl-2-phenyl-1H-imidazo[1,2-b]pyrazoles.
Scheme 15: Synthesis of 3,5-diaminopyrazole.
Scheme 16: Synthesis of 5-amino-4-cyanopyrazole and 5-amino-3-hydrazinopyrazole.
Scheme 17: Synthesis of 3,5-diaminopyrazoles with substituted malononitriles.
Scheme 18: Synthesis of 3,5-diamino-4-oximinopyrazole.
Scheme 19: Synthesis of 4-arylazo-3,5-diaminopyrazoles.
Scheme 20: Synthesis of 3- or 5-amino-4-cyanopyrazoles.
Scheme 21: Synthesis of triazenopyrazoles.
Scheme 22: Synthesis of 5(3)-aminopyrazoles.
Scheme 23: Synthesis of 3-substituted 5-amino-4-cyanopyrazoles.
Scheme 24: Synthesis of 2-{[(1-acetyl-4-cyano-1H-pyrazol-5-yl)amino]methylene}malononitrile.
Scheme 25: Synthesis of 5-aminopyrazole carbodithioates and 5-amino-3-arylamino-1-phenylpyrazole-4-carboxamide...
Scheme 26: Synthesis of 5-amino-4-cyanopyrazoles.
Scheme 27: Synthesis of thiazolylpyrazoles.
Scheme 28: Synthesis of 5-amino-1-heteroaryl-3-methyl/aryl-4-cyanopyrazoles.
Scheme 29: Synthesis of 5-amino-3-methylpyrazole-4-carboxamide.
Scheme 30: Synthesis of 4-acylamino-3(5)-amino-5(3)-arylsulfanylpyrazoles.
Scheme 31: Synthesis of 5-amino-1-aryl-4-diethoxyphosphoryl-3-halomethylpyrazoles.
Scheme 32: Synthesis of substituted 5-amino-3-trifluoromethylpyrazoles 114 and 118.
Scheme 33: Solid-support synthesis of 5-N-alkylamino and 5-N-arylaminopyrazoles.
Scheme 34: Synthesis of 5-amino-1-cyanoacetyl-3-phenyl-1H-pyrazole.
Scheme 35: Synthesis of 3-substituted 5-amino-1-aryl-4-(benzothiazol-2-yl)pyrazoles.
Scheme 36: Synthesis of 5-amino-4-carbethoxy-3-methyl-1-(4-sulfamoylphenyl)pyrazole.
Scheme 37: Synthesis of inhibitors of hsp27-phosphorylation and TNFa-release.
Scheme 38: Synthesis of the diglycylpyrazole 142.
Scheme 39: Synthesis of 5-amino-1-aryl-4-benzoylpyrazole derivatives.
Scheme 40: Synthesis of 4-benzoyl-3,5-diamino-1-(2-cyanoethyl)pyrazole.
Scheme 41: Synthesis of the 5-aminopyrazole derivative 150.
Scheme 42: Synthesis of 3,5-diaminopyrazoles 153.
Scheme 43: Synthesis of 5-aminopyrazoles derivatives 155 via lithiated intermediates.
Scheme 44: Synthesis of 5-amino-4-(1,2,4-oxadiazol-5-yl)-pyrazoles 157.
Scheme 45: Synthesis of a 5-aminopyrazole with anticonvulsant activity.
Scheme 46: Synthesis of tetrasubstituted 5-aminopyrazole derivatives.
Scheme 47: Synthesis of substituted 5-aminopyrazoles from hydrazonoyl halides.
Scheme 48: Synthesis of 3-amino-5-phenylpyrazoles from isothiazoles.
Scheme 49: Synthesis of 5-aminopyrazoles via ring transformation.
RAFT polymers for protein recognition
- Alan F. Tominey,
- Julia Liese,
- Sun Wei,
- Klaus Kowski,
- Thomas Schrader and
- Arno Kraft
Beilstein J. Org. Chem. 2010, 6, No. 66, doi:10.3762/bjoc.6.66
- likely serve to occlude bulk solvent from the hot spot and lower the local dielectric constant [3][4]. With this principle in mind, several groups have designed relatively simple linear polymeric structures with branched ionic comonomers and thus achieved remarkable affinities and biological properties
Graphical Abstract
Figure 1: Structures of monomers 1–7 and chain transfer agent 8 used in the RAFT polymerizations.
Figure 2: a) Second derivative UV–vis spectra [17-19] observed during a full titration of a stock solution of RAFT c...
Figure 3: Isothermal calorimetric binding curves for selected polymer/protein host–guest pairs. a) Typical bi...
Figure 4: Graphical illustration of the potential binding mode on hemoglobin tetramer (represented as electro...
Shelf-stable electrophilic trifluoromethylating reagents: A brief historical perspective
- Norio Shibata,
- Andrej Matsnev and
- Dominique Cahard
Beilstein J. Org. Chem. 2010, 6, No. 65, doi:10.3762/bjoc.6.65
- , chemical and biological properties [3]. The specific physical and chemical properties of fluorine in fluorine containing compounds, especially its strong electronegativity, lipophilicity and reaction ability, differ dramatically from those of other halogens and thus lead to changes in the interaction
Graphical Abstract
Scheme 1: Preparation of the first electrophilic trifluoromethylating reagent and its reaction with a thiophe...
Scheme 2: Synthetic routes to S-CF3 and Se-CF3 dibenzochalcogenium salts.
Scheme 3: Synthesis of (trifluoromethyl)dibenzotellurophenium salts.
Scheme 4: Nitration of (trifluoromethyl)dibenzochalcogenium salts.
Scheme 5: Synthesis of a sulphonium salt with a bridged oxygen.
Scheme 6: Reactivity of (trifluoromethyl)dibenzochalcogenium salts.
Scheme 7: Pd(II)-Catalyzed ortho-trifluoromethylation of heterocycle-substituted arenes by Umemoto’s reagents....
Scheme 8: Mild electrophilic trifluoromethylation of β-ketoesters and silyl enol ethers.
Scheme 9: Enantioselective electrophilic trifluoromethylation of β-ketoesters.
Scheme 10: Preparation of water-soluble S-(trifluoromethyl)dibenzothiophenium salts.
Scheme 11: Method for large-scale preparation of S-(trifluoromethyl)dibenzothiophenium salts.
Scheme 12: Triflic acid catalyzed synthesis of 5-(trifluoromethyl)thiophenium salts.
Scheme 13: Trifluoromethylation of β-ketoesters and dicyanoalkylidenes by S-(trifluoromethyl)benzothiophenium ...
Scheme 14: Synthesis of chiral S-(trifluoromethyl)benzothiophenium salt 18 and attempt of enantioselective tri...
Scheme 15: Synthesis of O-(trifluoromethyl)dibenzofuranium salts.
Scheme 16: Photochemical O- and N-trifluoromethylation by 20b.
Scheme 17: Thermal O-trifluoromethylation of phenol by diazonium salt 19a. Effect of the counteranion.
Scheme 18: Thermal O- and N-trifluoromethylations.
Scheme 19: Method of preparation of S-(trifluoromethyl)diphenylsulfonium triflates.
Scheme 20: Reactivity of some S-(trifluoromethyl)diarylsulfonium triflates.
Scheme 21: One-pot synthesis of S-(trifluoromethyl)diarylsulfonium triflates.
Scheme 22: One-pot synthesis of Umemoto’s type reagents.
Scheme 23: Preparation of sulfonium salts by transformation of CF3− into CF3+.
Scheme 24: Selected reactions with the new Yagupolskii reagents.
Scheme 25: Synthesis of heteroaryl-substituted sulfonium salts.
Scheme 26: First neutral S-CF3 reagents.
Scheme 27: Synthesis of Togni reagents. aYield for the two-step procedure.
Scheme 28: Trifluoromethylation of C-nucleophiles with 37.
Scheme 29: Selected examples of trifluoromethylation of S-nucleophiles with 37.
Scheme 30: Selected examples of trifluoromethylation of P-nucleophiles with 35 and 37.
Scheme 31: Trifluoromethylation of 2,4,6-trimethylphenol with 35.
Scheme 32: Examples of O-trifluoromethylation of alcohols with 35 in the presence of 1 equiv of Zn(NTf2)2.
Scheme 33: Formation of trifluoromethyl sulfonates from sulfonic acids and 35.
Scheme 34: Organocatalytic α-trifluoromethylation of aldehydes with 37.
Scheme 35: Synthesis of reagent 42 and mechanism of trifluoromethylation.
Scheme 36: Trifluoromethylation of β-ketoesters and dicyanoalkylidenes with 42.
One-pot three-component synthesis of quinoxaline and phenazine ring systems using Fischer carbene complexes
- Priyabrata Roy and
- Binay Krishna Ghorai
Beilstein J. Org. Chem. 2010, 6, No. 52, doi:10.3762/bjoc.6.52
- . Keywords: azaisobenzofuran; Diels–Alder; Fischer carbene complex; phenazine; quinoxaline; Introduction Nitrogen-containing heterocycles are abundant in nature and exhibit diverse and important biological properties [1]. Quinoxaline and phenazine derivatives are important classes of nitrogen containing
Graphical Abstract
Scheme 1: Synthetic plan towards quinoxaline derivatives.
Scheme 2: Preparation of o-alkynyl carbonyl derivatives 1. A: pyrazine series; B,C: quinoxaline series.
Scheme 3: Synthesis of quinoxaline derivative.
Scheme 4: Synthesis of azahydrophenanthrone derivatives.
Chemical aminoacylation of tRNAs with fluorinated amino acids for in vitro protein mutagenesis
- Shijie Ye,
- Allison Ann Berger,
- Dominique Petzold,
- Oliver Reimann,
- Benjamin Matt and
- Beate Koksch
Beilstein J. Org. Chem. 2010, 6, No. 40, doi:10.3762/bjoc.6.40
- unique properties of the fluorine atom, the incorporation of amino acids which contain fluorinated side chains into peptides and proteins is becoming increasingly popular for the rational design of biopolymers and materials with novel biological properties. For example, certain fluorinated analogues of
Graphical Abstract
Figure 1: General strategy of using a chemically aminoacylated suppressor tRNA and an in vitro translation sy...
Figure 2: Structures of non-canonical amino acids. a. (S)-ethylglycine, b. (S)-2-amino-4,4-difluorobutanoic a...
Scheme 1: General scheme for the synthesis of an N-(4-pentenoyl) amino acid cyanomethyl ester.
Scheme 2: General scheme of synthesis of mono-2′(3′)-O-[N-(4-pentenoyl)aminoacyl]-pdCpAs and 2′-3′-bis-O-[N-(...
Figure 3: Denaturing PAGE of ligation products of truncated suppressor tRNA and fluorinated aminoacyl-pdCpAs ...
Molecular recognition of organic ammonium ions in solution using synthetic receptors
- Andreas Späth and
- Burkhard König
Beilstein J. Org. Chem. 2010, 6, No. 32, doi:10.3762/bjoc.6.32
- recognition of chiral ammonium ions by crown ethers Chiral ammonium salts are found in many biologically active molecules. The enantioselective discrimination of such molecules is of interest as the biological properties of enantiomers may differ [131]. Since Cram et al. synthesized BINAP-crown ethers, which
Graphical Abstract
Figure 1: Biologically important amines and quaternary ammonium salts: histamine (1), dopamine (2) and acetyl...
Figure 2: Crown ether 18-crown-6.
Figure 3: Conformations of 18-crown-6 (4) in solvents of different polarity.
Figure 4: Binding topologies of the ammonium ion depending on the crown ring size.
Figure 5: A “pseudorotaxane” structure consisting of 24-crown-8 and a secondary ammonium ion (5); R = Ph.
Figure 6: Typical examples of azacrown ethers, cryptands and related aza macrocycles.
Figure 7: Binding of ammonium to azacrown ethers and cryptands [111-113].
Figure 8: A 19-crown-6-ether with decalino blocking groups (11) and a thiazole-dibenzo-18-crown-6-ether (12).
Figure 9: 1,3-Bis(6-oxopyridazin-1-yl)propane derivatives 13 and 14 by Campayo et al.
Figure 10: Fluorescent azacrown-PET-sensors based on coumarin.
Figure 11: Two different pyridino-cryptands (17 and 18) compared to a pyridino-crown (19); chiral ammonium ion...
Figure 12: Pyridino-18-crown-6 ligand (21), a similar acridino-18-crown-6 ligand (22) and a structurally relat...
Figure 13: Ciral pyridine-azacrown ether receptors 24.
Figure 14: Chiral 15-crown-5 receptors 26 and an analogue 18-crown-6 ligand 27 derived from amino alcohols.
Figure 15: C2-symmetric chiral 18-crown-6 amino alcohol derivatives 28 and related macrocycles.
Figure 16: Macrocycles with diamide-diester groups (30).
Figure 17: C2-symmetric chiral aza-18-crown-6 ethers (31) with phenethylamine residues.
Figure 18: Chiral C-pivot p-methoxy-phenoxy-lariat ethers.
Figure 19: Chiral lariat crown ether 34.
Figure 20: Sucrose-based chiral crown ether receptors 36.
Figure 21: Permethylated fructooligosaccharide 37 showing induced-fit chiral recognition.
Figure 22: Biphenanthryl-18-crown-6 derivative 38.
Figure 23: Chiral lariat crown ethers derived from binol by Fuji et al.
Figure 24: Chiral phenolic crown ether 41 with “aryl chiral barriers” and guest amines.
Figure 25: Chiral bis-crown receptor 43 with a meso-ternaphthalene backbone.
Figure 26: Chromogenic pH-dependent bis-crown chemosensor 44 for diamines.
Figure 27: Triamine guests for binding to receptor 44.
Figure 28: Chiral bis-crown phenolphthalein chemosensors 46.
Figure 29: Crown ether amino acid 47.
Figure 30: Luminescent receptor 48 for bis-alkylammonium guests.
Figure 31: Luminescent CEAA (49a), a bis-CEAA receptor for amino acids (49b) and the structure of lysine bindi...
Figure 32: Luminescent CEAA tripeptide for binding small peptides.
Figure 33: Bis crown ether 51a self assembles co-operatively with C60-ammonium ion 51b.
Figure 34: Triptycene-based macrotricyclic dibenzo-[24]-crown-8 ether host 52 and guests.
Figure 35: Copper imido diacetic acid azacrown receptor 53a and the suggested His-Lys binding motif; a copper ...
Figure 36: Urea (54) and thiourea (55) benzo crown receptor for transport and extraction of amino acids.
Figure 37: Crown pyryliums ion receptors 56 for amino acids.
Figure 38: Ditopic sulfonamide bridged crown ether receptor 57.
Figure 39: Luminescent peptide receptor 58.
Figure 40: Luminescent receptor 59 for the detection of D-glucosamine hydrochloride in water/ethanol and lumin...
Figure 41: Guanidinium azacrown receptor 61 for simple amino acids and ditopic receptor 62 with crown ether an...
Figure 42: Chiral bicyclic guanidinium azacrown receptor 63 and similar receptor 64 for the enantioselective t...
Figure 43: Receptors for zwitterionic species based on luminescent CEAAs.
Figure 44: 1,10-Azacrown ethers with sugar podand arms and the anticancer agent busulfan.
Figure 45: Benzo-18-crown-6 modified β-cyclodextrin 69 and β-cyclodextrin functionalized with diaza-18-crown-6...
Figure 46: Receptors for colorimetric detection of primary and secondary ammonium ions.
Figure 47: Porphyrine-crown-receptors 72.
Figure 48: Porphyrin-crown ether conjugate 73 and fullerene-ammonium ion guest 74.
Figure 49: Calix[4]arene (75a), homooxocalix[4]arene (75b) and resorcin[4]arene (75c) compared (R = H, alkyl c...
Figure 50: Calix[4]arene and ammonium ion guest (R = H, alkyl, OAcyl etc.), possible binding sites; A: co-ordi...
Figure 51: Typical guests for studies with calixarenes and related molecules.
Figure 52: Lower rim modified p-tert-butylcalix[5]arenes 82.
Figure 53: The first example of a water soluble calixarene.
Figure 54: Sulfonated water soluble calix[n]arenes that bind ammonium ions.
Figure 55: Displacement assay for acetylcholine (3) with a sulfonato-calix[6]arene (84b).
Figure 56: Amino acid inclusion in p-sulfonatocalix[4]arene (84a).
Figure 57: Calixarene receptor family 86 with upper and lower rim functionalization.
Figure 58: Calix[6]arenes 87 with one carboxylic acid functionality.
Figure 59: Sulfonated calix[n]arenes with mono-substitution at the lower rim systematically studied on their r...
Figure 60: Cyclotetrachromotropylene host (91) and its binding to lysine (81c).
Figure 61: Calixarenes 92 and 93 with phosphonic acids groups.
Figure 62: Calix[4]arene tetraphosphonic acid (94a) and a double bridged analogue (94b).
Figure 63: Calix[4]arene tetraphosphonic acid ester (92c) for surface recognition experiments.
Figure 64: Calixarene receptors 95 with α-aminophosphonate groups.
Figure 65: A bridged homocalix[3]arene 95 and a distally bridged homocalix[4]crown 96.
Figure 66: Homocalix[3]arene ammonium ion receptor 97a and the Reichardt’s dye (97b) for colorimetric assays.
Figure 67: Chromogenic diazo-bridged calix[4]arene 98.
Figure 68: Calixarene receptor 99 by Huang et al.
Figure 69: Calixarenes 100 reported by Parisi et al.
Figure 70: Guest molecules for inclusion in calixarenes 100: DAP × 2 HCl (101a), APA (101b) and Lys-OMe × 2 HC...
Figure 71: Different N-linked peptido-calixarenes open and with glycol chain bridges.
Figure 72: (S)-1,1′-Bi-2-naphthol calixarene derivative 104 published by Kubo et al.
Figure 73: A chiral ammonium-ion receptor 105 based on the calix[4]arene skeleton.
Figure 74: R-/S-phenylalaninol functionalized calix[6]arenes 106a and 106b.
Figure 75: Capped homocalix[3]arene ammonium ion receptor 107.
Figure 76: Two C3 symmetric capped calix[6]arenes 108 and 109.
Figure 77: Phosphorous-containing rigidified calix[6]arene 110.
Figure 78: Calix[6]azacryptand 111.
Figure 79: Further substituted calix[6]azacryptands 112.
Figure 80: Resorcin[4]arene (75c) and the cavitands (113).
Figure 81: Tetrasulfonatomethylcalix[4]resorcinarene (114).
Figure 82: Resorcin[4]arenes (115a/b) and pyrogallo[4]arenes (115c, 116).
Figure 83: Displacement assay for acetylcholine (3) with tetracyanoresorcin[4]arene (117).
Figure 84: Tetramethoxy resorcinarene mono-crown-5 (118).
Figure 85: Components of a resorcinarene based displacement assay for ammonium ions.
Figure 86: Chiral basket resorcin[4]arenas 121.
Figure 87: Resorcinarenes with deeper cavitand structure (122).
Figure 88: Resorcinarene with partially open deeper cavitand structure (123).
Figure 89: Water-stabilized deep cavitands with partially structure (124, 125).
Figure 90: Charged cavitands 126 for tetralkylammonium ions.
Figure 91: Ditopic calix[4]arene receptor 127 capped with glycol chains.
Figure 92: A calix[5]arene dimer for diammonium salt recognition.
Figure 93: Calixarene parts 92c and 129 for the formation molecular capsules.
Figure 94: Encapsulation of a quaternary ammonium cation by two resorcin[4]arene molecules (NMe4+@[75c]2 × Cl−...
Figure 95: Encapsulation of a quaternary ammonium cation by six resorcin[4]arene molecules (NMe3D+@[130]6 × Cl−...
Figure 96: Structure and schematic of cucurbit[6]uril (CB[6], 131a).
Figure 97: Cyclohexanocucurbit[6]uril (CB′[6], 132) and the guest molecule spermine (133).
Figure 98: α,α,δ,δ-Tetramethylcucurbit[6]uril (134).
Figure 99: Structure of the cucurbituril-phthalhydrazide analogue 135.
Figure 100: Organic cavities for the displacement assay for amine differentiation.
Figure 101: Displacement assay methodology for diammonium- and related guests involving cucurbiturils and some ...
Figure 102: Nor-seco-Cucurbituril (±)-bis-ns-CB[6] (140) and guest molecules.
Figure 103: The cucurbit[6]uril based complexes 141 for chiral discrimination.
Figure 104: Cucurbit[7]uril (131c) and its ferrocene guests (142) opposed.
Figure 105: Cucurbit[7]uril (131c) guest inclusion and representative guests.
Figure 106: Cucurbit[7]uril (131c) binding to succinylcholine (145) and different bis-ammonium and bis-phosphon...
Figure 107: Paraquat-cucurbit[8]uril complex 149.
Figure 108: Gluconuril-based ammonium receptors 150.
Figure 109: Examples of clefts (151a), tweezers (151b, 151c, 151d) and clips (151e).
Figure 110: Kemp’s triacid (152a), on example of Rebek’s receptors (152b) and guests.
Figure 111: Amino acid receptor (154) by Rebek et al.
Figure 112: Hexagonal lattice designed hosts by Bell et al.
Figure 113: Bell’s amidinium receptor (156) and the amidinium ion (157).
Figure 114: Aromatic phosphonic acids.
Figure 115: Xylene phosphonates 159 and 160a/b for recognition of amines and amino alcohols.
Figure 116: Bisphosphonate recognition motif 161 for a colorimetric assay with alizarin complexone (163) for ca...
Figure 117: Bisphosphonate/phosphate clip 164 and bisphosphonate cleft 165.
Figure 118: N-Methylpyrazine 166a, N-methylnicotinamide iodide (166b) and NAD+ (166c).
Figure 119: Bisphosphate cavitands.
Figure 120: Bisphosphonate 167 of Schrader and Finocchiaro.
Figure 121: Tweezer 168 for noradrenaline (80b).
Figure 122: Different tripods and heparin (170).
Figure 123: Squaramide based receptors 172.
Figure 124: Cage like NH4+ receptor 173 of Kim et al.
Figure 125: Ammonium receptors 174 of Chin et al.
Figure 126: 2-Oxazolin-based ammonium receptors 175a–d and 176 by Ahn et al.
Figure 127: Racemic guest molecules 177.
Figure 128: Tripods based on a imidazole containing macrocycle (178) and the guest molecules employed in the st...
Figure 129: Ammonium ion receptor 180.
Figure 130: Tetraoxa[3.3.3.3]paracyclophanes 181 and a cyclophanic tetraester (182).
Figure 131: Peptidic bridged paraquat-cyclophane.
Figure 132: Shape-selective noradrenaline host.
Figure 133: Receptor 185 for binding of noradrenaline on surface layers from Schrader et al.
Figure 134: Tetraphosphonate receptor for binding of noradrenaline.
Figure 135: Tetraphosphonate 187 of Schrader and Finocchiaro.
Figure 136: Zinc-Porphyrin ammonium-ion receptors 188 and 189 of Mizutani et al.
Figure 137: Zinc porphyrin receptor 190.
Figure 138: Zinc porphyrin receptors 191 capable of amino acid binding.
Figure 139: Zinc-porphyrins with amino acid side chains for stereoinduction.
Figure 140: Bis-zinc-bis-porphyrin based on Tröger’s base 193.
Figure 141: BINAP-zinc-prophyrin derivative 194 and it’s guests.
Figure 142: Bisaryl-linked-zinc-porphyrin receptors.
Figure 143: Bis-zinc-porphyrin 199 for diamine recognition and guests.
Figure 144: Bis-zinc-porphyrin crown ether 201.
Figure 145: Bis-zinc-porphyrin 202 for stereodiscrimination (L = large substituent; S = small substituent).
Figure 146: Bis-zinc-porphyrin[3]rotaxane and its copper complex and guests.
Figure 147: Dien-bipyridyl ligand 206 for co-ordination of two metal atoms.
Figure 148: The ligand and corresponding tetradentate co-complex 207 serving as enantioselective receptor for a...
Figure 149: Bis(oxazoline)–copper(II) complex 208 for the recognition of amino acids in aqueous solution.
Figure 150: Zinc-salen-complexes 209 for the recognition tertiary amines.
Figure 151: Bis(oxazoline)–copper(II) 211 for the recognition of amino acids in aqueous solution.
Figure 152: Zn(II)-complex of a C2 terpyridine crown ether.
Figure 153: Displacement assay and receptor for aspartate over glutamate.
Figure 154: Chiral complex 214 for a colorimetric displacement assay for amino acids.
Figure 155: Metal complex receptor 215 with tripeptide side arms.
Figure 156: A sandwich complex 216 and its displaceable dye 217.
Figure 157: Lanthanide complexes 218–220 for amino acid recognition.
Figure 158: Nonactin (221), valinomycin (222) and vancomycin (223).
Figure 159: Monesin (224a) and a chiral analogue for enantiodiscrimination of ammonium guests (224b).
Figure 160: Chiral podands (226) compared to pentaglyme-dimethylether (225) and 18-crown-6 (4).
Figure 161: Lasalocid A (228).
Figure 162: Lasalocid derivatives (230) of Sessler et al.
Figure 163: The Coporphyrin I tetraanion (231).
Figure 164: Linear and cyclic peptides for ammonium ion recognition.
Figure 165: Cyclic and bicyclic depsipeptides for ammonium ion recognition.
Figure 166: α-Cyclodextrin (136a) and novocaine (236).
Figure 167: Helical diol receptor 237 by Reetz and Sostmann.
Figure 168: Ammonium binding spherand by Cram et al. (238a) and the cyclic[6]metaphenylacetylene 238b in compar...
Figure 169: Receptor for peptide backbone and ammonium binding (239).
Figure 170: Anion sensor principle with 3-hydroxy-2-naphthanilide of Jiang et al.
Figure 171: 7-bromo-3-hydroxy-N-(2-hydroxyphenyl)naphthalene 2-carboxamide (241) and its amine binding.
Figure 172: Naturally occurring catechins with affinity to quaternary ammonium ions.
Figure 173: Spiropyran (244) and merocyanine form (244a) of the amino acid receptors of Fuji et al.
Figure 174: Coumarin aldehyde (245) and its iminium species with amino acid bound (245a) by Glass et al.
Figure 175: Coumarin aldehyde appended with boronic acid.
Figure 176: Quinolone aldehyde dimers by Glass et al.
Figure 177: Chromogenic ammonium ion receptors with trifluoroacetophenone recognition motifs.
Figure 178: Chromogenic ammonium ion receptor with trifluoroacetophenone recognition motif bound on different m...
(Pseudo)amide-linked oligosaccharide mimetics: molecular recognition and supramolecular properties
- José L. Jiménez Blanco,
- Fernando Ortega-Caballero,
- Carmen Ortiz Mellet and
- José M. García Fernández
Beilstein J. Org. Chem. 2010, 6, No. 20, doi:10.3762/bjoc.6.20
- blocks is inspired by the structure of peptides and the potential of carbohydrates to reproduce the structural features and biological properties of these polymers [12][13][17]. Poor bioavailability and metabolic stability of peptides have resulted in significant limitations as drug candidates. Another
- been synthesised [99]. Phosphoramidite 56 (Figure 24) was used as a building block to introduce guanidinium linkages at desired positions in the chimeric oligonucleotides. The biological properties were evaluated using the bcr-abl oncogene (the cause of chronic myeloid leukaemia) as the target. The
- groove. As in the case of RNG, a 20 base pair DNG/DNA chimera has been synthesised [106]. Phosphoramidite 66 (Figure 26) was used as the starting material for the introduction of guanidinium linkages at desired positions in the chimeric oligonucleotides. The biological properties were evaluated using the
Graphical Abstract
Figure 1: Schematic representation of sugar aminoacids (SAAs) and (pseudo)amide oligosaccharide mimetics.
Figure 2: Natural SAAs structures and natural nucleosidic antibiotics.
Scheme 1: Synthetic route to the target amide-linked sialooligomers. (a) Fmoc-Cl, NaHCO3, H2O, dioxane, 0 °C....
Figure 3: The general structure of glycoamino acids and their corresponding oligomers.
Figure 4: Conformational analysis of the β(1→2)-amide-linked glucooligomer 9.
Figure 5: Short oligomeric chains of C-glycosyl D-arabino THF amino acid oligomers.
Figure 6: (A) Stereoview of the minimized structure of compound 16 (produced by a 500 ps simulation) that mos...
Figure 7: Structures of linear oxetane-β- and δ-SAA homo-oligomers 19–20.
Figure 8: 10-Membered ring H-bonds in compound 21 consistent with NMR and modelling investigations.
Figure 9: General structure of carbopeptoid-oligonucleotide conjugates.
Figure 10: Protected derivatives of 2,6-diamino-2,6-dideoxy-β-D-glucopyranosyl carboxylic acid 22 and 23.
Figure 11: Cyclic homo-oligomers containing glucopyranoid-SAAs.
Scheme 2: Strategy for solid-phase synthesis of cyclic trimers and tetramers containing pyranoid δ-SAAs.
Figure 12: Cyclic tetramers of L-rhamno- and D-gulo-configured oxetane-SAAs.
Figure 13: Aminoglycosidic antibiotics of the glycocinnamoylspermidine family.
Scheme 3: Synthesis of (thio)trehazoline, via triflate, from β-hydroxy(thio)urea.
Figure 14: Approaches to access pseudoamide-type oligosaccharide mimics.
Figure 15: Calystegine B2 analogues 38 and 39 with urea-linked disaccharide structure.
Figure 16: Rotameric equilibrium shift of 40 by formation of a bidentate hydrogen bond.
Figure 17: Nucleotide analogues with thiourea and S-methylisothiouronium linkers.
Scheme 4: Retrosynthetic approach to synthesize thiourea-linked glycooligomers.
Figure 18: Rotameric equilibria for β-(1→6)-thiourea-linked glucodimer 41.
Figure 19: Schematic representation of (a) cyclodextrin (CDs) and (b) cyclotrehalan (CTs) family members.
Scheme 5: Synthesis of guanidine-linked pseudodisaccharides via carbodiimide.
Figure 20: β(1→6)-Guanidine-linked pseudodi- and pseudotrisaccharides 47 and 48.
Scheme 6: Synthesis of N-benzylguanidine-linked CT2 50.
Figure 21: Structure of RNG and DNG.
Figure 22: Preparation of Fmoc-guanidinium derivatives.
Figure 23: Structures of the homo-oligomeric RNG derivatives 51–55.
Figure 24: Phosphoramidite building block 56.
Figure 25: Structures of DNGs 57–65.
Figure 26: Structure of the phosphoramidite building block 66.
Mitomycins syntheses: a recent update
- Jean-Christophe Andrez
Beilstein J. Org. Chem. 2009, 5, No. 33, doi:10.3762/bjoc.5.33
- -alkylation of DNA [3]. The decisive role of the aziridine is far from unusual since its presence in a small number of other naturally occurring molecules such as azinomycins [4][5], FR-900482 [6], maduropeptin [7], and azicemicins [8] is accompanied by significant biological properties (Scheme 1) [3][9
Graphical Abstract
Scheme 1: Aziridine containing natural products.
Scheme 2: Mitomycin structures and nomenclature.
Scheme 3: Base catalysed epimerization of mitomycin B.
Scheme 4: Biosynthesis of mitomycin C (MMC) 7.
Scheme 5: Mode of action of mitomycin C.
Scheme 6: The N–C3–C9a disconnection.
Scheme 7: Danishefsky’s Retrosynthesis of mitomycin K.
Scheme 8: Hetero Diels–Alder reaction en route to mitomycins.
Scheme 9: Nitroso Diels–Alder cycloaddition.
Scheme 10: Frank azide cycloadddition.
Scheme 11: Final steps of mitomycin K synthesis. aPDC, DCM; bPhSCH2N3, PhH, 80 °C; cL-selectride, THF, −78 °C; ...
Scheme 12: Naruta–Maruyama retrosynthesis.
Scheme 13: Synthesis of a leucoaziridinomitosane by nitrene cycloaddition. aAlCl3-Et2O; bNaH, ClCH2OMe; cn-BuL...
Scheme 14: Thermal decomposition of azidoquinone 51.
Scheme 15: Diastereoselectivity during the cycloaddition.
Scheme 16: Oxidation with iodo-azide.
Scheme 17: Williams’ approach towards mitomycins.aDEIPSCl, Imidazole, DCM; bPd/C, HCO2NH4, MeOH; cAllocCl, NaH...
Scheme 18: Synthesis of pyrrolidones by homoconjugate addition.
Scheme 19: Homoconjugate addition on the fully functionalized substrate.
Scheme 20: Introduction of the olefin.
Scheme 21: Retrosynthesis of N–C9a, N–C3 bond formation.
Scheme 22: Synthesis of the pyrrolo[1,2]indole 82 using N-PSP activation.aAc2O, Py; bAc2O, Hg(OAc)2, AcOH, 90%...
Scheme 23: Synthesis of an aziridinomitosane. am-CPBA, DCM then iPr2NH, CCl4 reflux; bK2CO3, MeOH; cBnBr, KH; d...
Scheme 24: Oxidation products of a leucoaziridinomitosane obtained from a Polonovski oxidation.
Scheme 25: Polonovski oxidation of an aziridinomitosane. am-CPBA; bPd/C, H2; cDimethoxypropane, PPTS.
Scheme 26: The C1–C9a disconnection.
Scheme 27: Ziegler synthesis of desmethoxymitomycin A.aIm2C=O, THF; bNH3; cTMSOTf, 2,6-di-tert-butylpyridine, ...
Scheme 28: Transformation of sodium erythorbate.aTBDMSCl; bNaN3; cPPh3; d(Boc)2O, DMAP; eTBAF; fTf2O, Pyr.
Scheme 29: Formation of C9,C10-unsaturation in the mitomycins. am-CPBA, DCM; bO3, MeOH; cMe2S; dKHMDS, (EtO)3P...
Scheme 30: Fragmentation mechanism.
Scheme 31: Michael addition-cyclisation.
Scheme 32: SmI2 8-endo-dig cyclisation.
Scheme 33: Synthesis of pyrrolo[1,2-a]indole by 5-exo-dig radical cyclization.
Scheme 34: The C9–C9a disconnection.
Scheme 35: Intramolecular nitrile oxide cycloaddition.
Scheme 36: Regioselectivity of the INOC.
Scheme 37: Fukuyama’s INOC strategy.
Scheme 38: Synthesis of a mitosane core by rearrangement of a 1-(1-pyrrolidinyl)-1,3-butadiene.
Scheme 39: Sulikowski synthesis of an aziridinomitosene. aPd(Tol3P)2Cl2, Bu3SnF, 140; bH2, Pd/C; cTFAA, Et3N; d...
Scheme 40: Enantioselective carbene insertion.
Scheme 41: Parson’s radical cyclization.
Scheme 42: Cha’s mitomycin B core synthesis.
Scheme 43: The N-aromatic disconnection.
Scheme 44: Kishi retrosynthesis.
Scheme 45: Kishi synthesis of a starting material. aallyl bromide, K2CO3, acetone, reflux; bN,N-Dimethylanilin...
Scheme 46: Kishi synthesis of MMC 7. aLDA, THF, −78 °C then PhSeBr, THF, −78 °C; bH2O2, THF-EtOAc; cDIBAL, DCM...
Scheme 47: Acid catalyzed degradation of MMC 7.
Scheme 48: In vivo formation of apomitomycin B.
Scheme 49: Advanced intermediate for apomitomycin B synthesis.
Scheme 50: Remers synthesis of a functionalized mitosene. aTMSCl, Et3N, ZnCl2 then NBS; bAcOK; cNH2OH; dPd/C, H...
Scheme 51: Coleman synthesis of desmethoxymitomycin A. aSnCl2, PhSH, Et3N, CH3CN; bClCO2Bn, Et3N; cPPh3, DIAD,...
Scheme 52: Transition state and pyrrolidine synthesis.
Scheme 53: Air oxidation of mitosanes and aziridinomitosanes.
Scheme 54: The C9-aromatic disconnection.
Scheme 55: Synthesis of the aziridine precursor. aLHMDS, THF; bNaOH; c(s)-α-Me-BnNH2, DCC, HOBT; dDIBAL; eK2CO3...
Scheme 56: Synthesis of 206 via enamine conjugate addition.
Scheme 57: Rapoport synthesis of an aziridinomitosene.
Scheme 58: One pot synthesis of a mitomycin analog.
Scheme 59: Synthesis of compound 218 via intramolecular Heck coupling. aEtMgCl, THF, then 220; bMsCl, Et3N; cN...
Scheme 60: Elaboration of indole 223. aEt3N, Ac2O; bAcOH; cSOCl2, Et3N; dNaN3, DMF; eH2SO4, THF; fK2CO3, MeOH; ...
Scheme 61: C9-C9a functionalization from indole.
Scheme 62: Synthesis of mitomycin K. a2 equiv. MoO5.HMPA, MeOH; bPPh3, Et3N, THF-H2O; cMeOTf, Py, DCM; dMe3SiCH...
Scheme 63: Configurational stability of mitomycin K derivatives.
Scheme 64: Epimerization of carbon C9a in compound 227b.
Scheme 65: Corey–Chaykovsky synthesis of indol 235.
Scheme 66: Cory intramolecular aza-Darzens reaction for the formation of aziridinomitosene 239.
Scheme 67: Jimenez synthesis of aziridinomitosene 242.
Scheme 68: Von Braun opening of indoline 244.
Scheme 69: C9a oxidation of an aziridinomitosane with DDQ/OsO4.
Scheme 70: Synthesis of epi-mitomycin K. aNaH, Me2SO4; bH2, Pd/C; cMitscher reagent [165]; d[(trimethylsilyl)methyl...
Scheme 71: Mitomycins rearrangement.
Scheme 72: Fukuyama’s retrosynthesis.
Scheme 73: [2+3] Cycloaddition en route to isomitomycin A. aToluene, 110 °C; bDIBAL, THF, −78 °C; cAc2O, Py.; d...
Scheme 74: Final steps of Fukuyama’s synthesis.
Scheme 75: “Crisscross annulation”.
Scheme 76: Synthesis of 274; the 8-membered ring 274 was made using a crisscross annulation. a20% Pd(OH)2/C, H2...
Scheme 77: Conformational analysis of compound 273 and 275.
Scheme 78: Synthesis of a mitomycin analog. aNa2S2O4, H2O, DCM; bBnBr (10 equiv), K2CO3, 18-crown-6 (cat.), TH...
Scheme 79: Vedejs retrosynthesis.
Scheme 80: Formation of the azomethine ylide.
Scheme 81: Vedejs second synthesis of an aziridinomitosene. aDIBAL; bTPAP, NMO; c287; dTBSCl, imidazole.
Scheme 82: Trityl deprotection and new aziridine protecting group 300.
Scheme 83: Ene reaction towards benzazocinones.
Scheme 84: Benzazocenols via homo-Brook rearrangement.
Scheme 85: Pt-catalyzed [3+2] cycloaddition.
Scheme 86: Carbonylative lactamization entry to benzazocenols. aZn(OTf)2, (+)-N-methylephedrine, Et3N, TMS-ace...
Scheme 87: 8 membered ring formation by RCM. aBOC2O, NaHCO3; bTBSCl, Imidazole, DMF; callyl bromide, NaH, DMF; ...
Scheme 88: Aziridinomitosene synthesis. aTMSN3; bTFA; cPOCl3, DMF; dNaClO2, NaH2PO4, 2-methyl-2-butene; eMeI, ...
Scheme 89: Metathesis from an indole.
Scheme 90: Synthesis of early biosynthetic intermediates of mitomycins.
(−)-Complanine, an inflammatory substance of marine fireworm: a synthetic study
- Kazuhiko Nakamura,
- Yu Tachikawa and
- Daisuke Uemura
Beilstein J. Org. Chem. 2009, 5, No. 12, doi:10.3762/bjoc.5.12
- ; thus, the biological properties of complanine can be understood as controlling this cascade [2]. From a structural perspective, complanine possesses amphipathic properties due to its characteristic unsaturated carbon chain and a γ-aminobutyric acid (GABA)-derived trimethylammonium substructure. Natural
- good agreement with the absolute configuration of the natural product. The biological activities of both enantiomers were examined, but no significant difference between them was observed based on the inflammatory activity on a mouse foot pad. Detailed biological properties (for example, PKC activation
Graphical Abstract
Figure 1: Structure of (R)-(−)-complanine.
Figure 2: Marine fireworm Eurythoe complanata (body length 10 cm).
Scheme 1: Total synthesis of complanine. Keys: a) 1. BH3·SMe2 (71%); 2. cat. TsOH, Et2CO (59%); 3. TsCl, pyri...
Recent progress on the total synthesis of acetogenins from Annonaceae
- Nianguang Li,
- Zhihao Shi,
- Yuping Tang,
- Jianwei Chen and
- Xiang Li
Beilstein J. Org. Chem. 2008, 4, No. 48, doi:10.3762/bjoc.4.48
- ]. More recently the annonaceous acetogenins have also been shown to overcome resistance in multidrug resistant (MDR) tumors [13]. Because of their structural diversity and the numerous biological properties, many authors are working on the total synthesis of ACGs. Previous reviews on the total synthesis
Graphical Abstract
Scheme 1: Total synthesis of longifolicin by Marshall’s group.
Scheme 2: Total synthesis of corossoline by Tanaka’s group.
Scheme 3: Total synthesis of corossoline by Wu’s group.
Scheme 4: Total synthesis of pseudo-annonacin A by Hanessian’s group.
Scheme 5: Total synthesis of tonkinecin by Wu’s group.
Scheme 6: Total synthesis of gigantetrocin A by Shi’s group.
Scheme 7: Total synthesis of annonacin by Wu’s group.
Scheme 8: Total synthesis of solamin by Kitahara’s group.
Scheme 9: Total synthesis of solamin by Mioskowski’s group.
Scheme 10: Total synthesis of cis-solamin by Makabe’s group.
Scheme 11: Total synthesis of cis-solamin by Brown’s group.
Scheme 12: The formal synthesis of (+)-cis-solamin by Donohoe’s group.
Scheme 13: Total synthesis of cis-solamin by Stark’s group.
Scheme 14: Total synthesis of mosin B by Tanaka’s group.
Scheme 15: Total synthesis of longicin by Hanessian’s group.
Scheme 16: Total synthesis of murisolin and 16,19-cis-murisolin by Tanaka’s group.
Scheme 17: Synthesis of a stereoisomer library of (+)-murisolin by Curran’s group.
Scheme 18: Total synthesis of murisolin by Makabe’s group.
Scheme 19: Total synthesis of reticulatain-1 by Makabe’s group.
Scheme 20: Total synthesis of muricatetrocin C by Ley’s group.
Scheme 21: Total synthesis of (4R,12S,15S,16S,19R,20R,34S)-muricatetrocin (146) and (4R,12R,15S,16S,19R,20R,34S...
Scheme 22: Total synthesis of parviflorin by Hoye’s group.
Scheme 23: Total synthesis of parviflorin by Trost’s group.
Scheme 24: Total synthesis of trilobacin by Sinha’s group.
Scheme 25: Total synthesis of 15-epi-annonin I 181b by Scharf’s group.
Scheme 26: Total synthesis of squamocin A and squamocin D by Scharf’s group.
Scheme 27: Total synthesis of asiminocin by Marshall’s group.
Scheme 28: Total synthesis of asiminecin by Marshall’s group.
Scheme 29: Total synthesis of (+)-(30S)-bullanin by Marshall’s group.
Scheme 30: Total synthesis of uvaricin by the group of Sinha and Keinan.
Scheme 31: Formal synthesis of uvaricin by Burke’s group.
Scheme 32: Total synthesis of trilobin by Marshall’s group.
Scheme 33: Total synthesis of trilobin by the group of Sinha and Keinan.
Scheme 34: Total synthesis of asimilobin by the group of Wang and Shi.
Scheme 35: Total synthesis of squamotacin by the group of Sinha and Keinan.
Scheme 36: Total synthesis of asimicin by Marshall’s group.
Scheme 37: Total synthesis of asimicin by the group of Sinha and Keinan.
Scheme 38: Total synthesis of asimicin by Roush’s group.
Scheme 39: Total synthesis of asimicin by Marshall’s group.
Scheme 40: Total synthesis of 10-hydroxyasimicin by Ley’s group.
Scheme 41: Total synthesis of asimin by Marshall’s group.
Scheme 42: Total synthesis of bullatacin by the group of Sinha and Keinan.
Scheme 43: Total synthesis of bullatacin by Roush’s group.
Scheme 44: Total synthesis of bullatacin by Pagenkopf’s group.
Scheme 45: Total synthesis of rollidecins C and D by the group of Sinha and Keinan.
Scheme 46: Total synthesis of 30(S)-hydroxybullatacin by Marshall’s group.
Scheme 47: Total synthesis of uvarigrandin A and 5(R)-uvarigrandin A by Marshall’s group.
Scheme 48: Total synthesis of membranacin by Brown’s group.
Scheme 49: Total synthesis of membranacin by Lee’s group.
Scheme 50: Total synthesis of rolliniastatin 1 and rollimembrin by Lee’s group.
Scheme 51: Total synthesis of longimicin D by the group of Maezaki and Tanaka.
Scheme 52: Total synthesis of the structure proposed for mucoxin by Borhan’s group.
Scheme 53: Modular synthesis of adjacent bis-THF annonaceous acetogenins by Marshall’s group.
Scheme 54: Total synthesis of 4-deoxygigantecin by Tanaka’s group.
Scheme 55: Total synthesis of squamostatins D by Marshall’s group.
Scheme 56: Total synthesis of gigantecin by Crimmins’s group.
Scheme 57: Total synthesis of gigantecin by Hoye’s group.
Scheme 58: Total synthesis of cis-sylvaticin by Donohoe’s group.
Scheme 59: Total synthesis of 17(S),18(S)-goniocin by Sinha’s group.
Scheme 60: Total synthesis of goniocin and cyclogoniodenin T by the group of Sinha and Keinan.
Scheme 61: Total synthesis of jimenezin by Takahashi’s group.
Scheme 62: Total synthesis of jimenezin by Lee’s group.
Scheme 63: Total synthesis of jimenezin by Hoffmann’s group.
Scheme 64: Total synthesis of muconin by Jacobsen’s group.
Scheme 65: Total synthesis of (+)-muconin by Kitahara’s group.
Scheme 66: Total synthesis of muconin by Takahashi’s group.
Scheme 67: Total synthesis of muconin by the group of Yoshimitsu and Nagaoka.
Scheme 68: Total synthesis of mucocin by the group of Sinha and Keinan.
Scheme 69: Total synthesis of mucocin by Takahashi’s group.
Scheme 70: Total synthesis of (−)-mucocin by Koert’s group.
Scheme 71: Total synthesis of mucocin by the group of Takahashi and Nakata.
Scheme 72: Total synthesis of mucocin by Evans’s group.
Scheme 73: Total synthesis of mucocin by Mootoo’s group.
Scheme 74: Total synthesis of (−)-mucocin by Crimmins’s group.
Scheme 75: Total synthesis of pyranicin by the group of Takahashi and Nakata.
Scheme 76: Total synthesis of pyranicin by Rein’s group.
Scheme 77: Total synthesis of proposed pyragonicin by the group of Takahashi and Nakata.
Scheme 78: Total synthesis of pyragonicin by Rein’s group.
Scheme 79: Total synthesis of pyragonicin by Takahashi’s group.
Scheme 80: Total synthesis of squamostanal A by Figadère’s group.
Scheme 81: Total synthesis of diepomuricanin by Tanaka’s group.
Scheme 82: Total synthesis of (−)-muricatacin [(R,R)-373a] and its enantiomer (+)-muricatacin [(S,S)-373b] by ...
Scheme 83: Total synthesis of epi-muricatacin (+)-(S,R)-373c and (−)-(R,S)-373d by Scharf’s group.
Scheme 84: Total synthesis of (−)-muricatacin 373a and 5-epi-(−)-muricatacin 373d by Uang’s group.
Scheme 85: Total synthesis of four stereoisomers of muricatacin by Yoon’s group.
Scheme 86: Total synthesis of (+)-muricatacin by Figadère’s group.
Scheme 87: Total synthesis of (+)-epi-muricatacin and (−)-muricatacin by Couladouros’s group.
Scheme 88: Total synthesis of muricatacin by Trost’s group.
Scheme 89: Total synthesis of (−)-(4R,5R)-muricatacin by Heck and Mioskowski’s group.
Scheme 90: Total synthesis of muricatacin (−)-373a by the group of Carda and Marco.
Scheme 91: Total synthesis of (−)- and (+)-muricatacin by Popsavin’s group.
Scheme 92: Total synthesis of (−)-muricatacin by the group of Bernard and Piras.
Scheme 93: Total synthesis of (−)-muricatacin by the group of Yoshimitsu and Nagaoka.
Scheme 94: Total synthesis of (−)-muricatacin by Quinn’s group.
Scheme 95: Total synthesis of montecristin by Brückner’s group.
Scheme 96: Total synthesis of (−)-acaterin by the group of Franck and Figadère.
Scheme 97: Total synthesis of (−)-acaterin by Singh’s group.
Scheme 98: Total synthesis of (−)-acaterin by Kumar’s group.
Scheme 99: Total synthesis of rollicosin by Quinn’s group.
Scheme 100: Total synthesis of Rollicosin by Makabe’s group.
Scheme 101: Total synthesis of squamostolide by Makabe’s group.
Scheme 102: Total synthesis of tonkinelin by Makabe’s group.
Phaeochromycins F–H, three new polyketide metabolites from Streptomyces sp. DSS-18
- Jian Li,
- Chun-Hua Lu,
- Bao-Bing Zhao,
- Zhong-Hui Zheng and
- Yue-Mao Shen
Beilstein J. Org. Chem. 2008, 4, No. 46, doi:10.3762/bjoc.4.46
- ), H (3), were obtained from the culture broth of marine actinomycete strain Streptomyces sp. DSS-18. Their structures were established on the basis of detailed spectroscopic analyses, including 1D-, 2D-NMR and HR-ESI MS techniques. Keywords: biological properties; isolation; polyketides; Streptomyces
- from marine derived actinomycetes, a strain of the genus Streptomyces was isolated from deep sediment collected from the west Pacific. Herein, we report the isolation and structure determination and biological properties of three new polyketides, namely phaeochromycins F (1), G (2) and H (3), from
Graphical Abstract
Figure 1: The fragments 1a and 1b of compounds 1 and compound 2, 3 and the selected HMBC correlations (H→C).
Synthesis of new triazole- based trifluoromethyl scaffolds
- Michela Martinelli,
- Thierry Milcent,
- Sandrine Ongeri and
- Benoit Crousse
Beilstein J. Org. Chem. 2008, 4, No. 19, doi:10.3762/bjoc.4.19
- . On the other hand, it is well known that the introduction of fluorine atoms or a fluoroalkyl group can greatly modify the physico-chemical features and thus the biological properties of a molecule (resistance to metabolic oxidation and hydrolysis, modification of pKa, hydrophobicity,...) [14][15][16
Graphical Abstract
Scheme 1: Synthetic approach to the trifluoromethyl triazoles.
Figure 1: Experimentally found NOE correlation for compound 2c.
Scheme 2: Cycloaddition of enantiopure propargylamine.
Stereoselective synthesis of (2S,3S,4Z)-4-fluoro- 1,3-dihydroxy- 2-(octadecanoylamino)octadec- 4-ene, [(Z)-4-fluoroceramide], and its phase behavior at the air/water interface
- Gergana S. Nikolova and
- Günter Haufe
Beilstein J. Org. Chem. 2008, 4, No. 12, doi:10.3762/bjoc.4.12
- formation of additional hydrogen bridges, which enhance the rigidity of the intercellular lipid aggregates and hence decrease the transepidermal water loss [24][25]. Several of the biological properties of sphingosines and ceramides (e.g. sphingomyelinase activity) were assigned to the OH group in the 3
Graphical Abstract
Figure 1: Natural sphingosines 1a, 2a and synthesized fluorinated analogues 1b, 2b.
Scheme 1: Synthesis of 4-fluorosphingosine (2b); Reagents: i ClTi(OEt)3/Et3N, CH2Cl2, 13 h, 0 °C; ii 15% aq c...
Scheme 2: Mechanism of the aldol reaction.
Figure 2: Favorable conformations of the tert-butyl amino acid ester 7.
Figure 3: π–A Isotherms of ceramide (2a) and 4-fluoroceramide (2b) at 20 °C (80 cm2/min compression velocity)....
Figure 4: Cycles of compression and expansion for ceramide (2a) and 4-fluoroceramide (2b).
Facile synthesis of two diastereomeric indolizidines corresponding to the postulated structure of alkaloid 5,9E- 259B from a Bufonid toad (Melanophryniscus)
- Angela Nelson,
- H. Martin Garraffo,
- Thomas F. Spande,
- John W. Daly and
- Paul J. Stevenson
Beilstein J. Org. Chem. 2008, 4, No. 6, doi:10.1186/1860-5397-4-6
- alkaloids from the natural sources, for the most part the biological properties of these materials have not been fully evaluated. However, synthetic 5,8-disubstituted indolizidine 5,9Z-235B' (Figure 1), has recently been shown to be a potent and selective non-competitive inhibitor of nicotinic acetylcholine
Graphical Abstract
Figure 1: Subclasses of diastereoisomeric 5,8-disubstituted alkaloids. The absolute stereochemistry of 5,9Z-2...
Scheme 1: Reagents: (i) MeMgI. 96% (ii) PTSA 71%. (iii) TiCl4 CH2Cl2 25 oC 3d 68%. (iv) MsCl, Et3N, THF -40 o...
Figure 2: EIMS spectra of a) natural 5,9E-259B, b) synthetic 7, and c) synthetic minor diastereomer of 7. Str...
Figure 3: Vapor-phase FTIR spectra of a) natural 5,9E-259B, and b) synthetic 7. Structure shown with relative...
Microwave assisted synthesis of triazoloquinazolinones and benzimidazoquinazolinones
- Aboul-Fetouh E. Mourad,
- Ashraf A. Aly,
- Hassan H. Farag and
- Eman A. Beshr
Beilstein J. Org. Chem. 2007, 3, No. 11, doi:10.1186/1860-5397-3-11
- -Minia University, 61519-El-Minia, Egypt 10.1186/1860-5397-3-11 Abstract Background Benzimidazoquinazolinones and related quinazolines are classes of heterocycles that are of considerable interest because of the diverse range of their biological properties. Although numerous classes of quinazolines have
- heterocycles that are of considerable interest because of the diverse range of their biological properties, including anticancer, [14] anti-inflammatory, [15] anticonvulsant, [16] and antidituric, [17] activities. Moreover, the imidazoquinazolinones have the activity to afford agents capable of lowering the
Graphical Abstract
Scheme 1: Synthesis of triazoloquinazolinones 4a-d via microwave irradiation.
Scheme 2: Oxidation of tetrahydrotriazoloquinazolinones.
Scheme 3: Synthesis of benzimidazoquinazolinones 8a-e via microwave irradiation.
