Synthesis and properties of some icosahedral carborane B,B'-dithiols

1980 ◽  
Vol 45 (6) ◽  
pp. 1775-1779 ◽  
Author(s):  
Jaromír Plešek ◽  
Zbyněk Janoušek ◽  
Stanislav Heřmánek
Keyword(s):  
Structure Analysis ◽  
Mass Spectra ◽  
X Ray ◽  
High Yields ◽  
Excess Sulfur

Reaction of icosahedral carboranes with excess sulfur over AlCl3 converts in high yields o-carborane to 9,12-, and m-carborane to 9,10- and 5(4),9-dithiols which were transformed by CH2Br2 to the appropriate cyclic thioformal derivatives. Reaction of 9,12(HS)2-1,2-C2B10H10 with acetone and AlCl3 afforded a cyclic thioketal, the structure of which was confirmed by X-ray structure analysis. All structures were proposed on the ground of 1H-, 11B-NMR and mass spectra.

Darstellung und Struktur kationischer η2-Thiocarbenkomplexe von Molybdän und Wolfram / Synthesis and Structure of Cationic η2-Thiocarbene Complexes of Molybdenum and Tungsten

1990 ◽  
Vol 45 (6) ◽  
pp. 921 ◽  
Author(s):  
N. Ullrich ◽  
C. Stegmair ◽  
H. Keller ◽  
E. Herdtweck ◽  
F. R. Kreißl
Keyword(s):  
Structure Analysis ◽  
Triple Bond ◽  
Mass Spectra ◽  
Electrophilic Attack ◽  
X Ray ◽  
High Yields ◽  
New Compounds ◽  
Carbyne Complexes ◽  
And Tungsten

The reaction of dimethyl(methylthio)sulfonium tetrafluoroborate [(CH3)2S–SCH3][BF4] with η/5-cyclopentadienyl(dicarbonyl)carbyne complexes of molybdenum and tungsten Cp(CO)2M ≡ C–R (M = Mo, W; R = CH3, C6H5, C6H4CH3) 1c, 2a–d results in an electrophilic attack of the SCH3 moiety at the metal carbon triple bond, providing orange to red, diamagnetic, cationic η2-thiocarbene complexes 3c, 4a–d in high yields. The new compounds were identified by X-ray structure analysis, NMR, IR and mass spectra.

scholarly journals Thiol-to-amine cyclization reaction enables screening of large libraries of macrocyclic compounds and the generation of sub-kilodalton ligands

2019 ◽  
Vol 5 (8) ◽  
pp. eaaw2851 ◽  
Author(s):  
S. S. Kale ◽  
M. Bergeron-Brlek ◽  
Y. Wu ◽  
M. G. Kumar ◽  
M. V. Pham ◽  
...  
Keyword(s):  
Drug Development ◽  
Structure Analysis ◽  
Drug Targets ◽  
Macrocyclic Ligands ◽  
Cyclization Reaction ◽  
Thrombin Inhibitor ◽  
Macrocyclic Compounds ◽  
Cyclization Reactions ◽  
X Ray ◽  
High Yields

Macrocyclic compounds are an attractive modality for drug development, but the limited availability of large, structurally diverse macrocyclic libraries hampers the discovery of leads. Here, we describe the discovery of efficient macrocyclization reactions based on thiol-to-amine ligations using bis-electrophiles, their application to synthesize and screen large libraries of macrocyclic compounds, and the identification of potent small macrocyclic ligands. The thiol-to-amine cyclization reactions showed unexpectedly high yields for a wide substrate range, which obviated product purification and enabled the generation and screening of an 8988 macrocycle library with a comparatively small effort. X-ray structure analysis of an identified thrombin inhibitor (Ki = 42 ± 5 nM) revealed a snug fit with the target, validating the strategy of screening large libraries with a high skeletal diversity. The approach provides a route for screening large sub-kilodalton macrocyclic libraries and may be applied to many challenging drug targets.

scholarly journals Synthesis of New Planar-Chiral Linked [2.2]Paracyclophanes-N-([2.2]-Paracyclophanylcarbamoyl)-4-([2.2]Paracyclophanylcarboxamide, [2.2]Paracyclophanyl-Substituted Triazolthiones and -Substituted Oxadiazoles

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3315
Author(s):  
Ashraf A. Aly ◽  
Stefan Bräse ◽  
Alaa A. Hassan ◽  
Nasr K. Mohamed ◽  
Lamiaa E. Abd El-Haleem ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Acid Chloride ◽  
Mass Spectra ◽  
Enantiomeric Purity ◽  
X Ray ◽  
Hplc Purification

The manuscript describes the synthesis of new racemic and chiral linked paracyclophane assigned as N-5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carbamoyl)-5’-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carboxamide. The procedure depends upon the reaction of 5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)hydrazide with 5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)isocyanate. To prepare the homochiral linked paracyclophane of a compound, the enantioselectivity of 5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carbaldehyde (enantiomeric purity 60% ee), was oxidized to the corresponding acid, which on chlorination, gave the corresponding acid chloride of [2.2]paracyclophane. Following up on the same procedure applied for the preparation of racemic-carbamoyl and purified by HPLC purification, we succeeded to obtain the target Sp-Sp-N-5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carbamoyl)-5’-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)carboxamide. Subjecting N-5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)hydrazide to various isothiocyanates, the corresponding paracyclophanyl-acylthiosemicarbazides were obtained. The latter compounds were then cyclized to a new series of 5-(1,4(1,4)-dibenzenacyclohexaphane-12-yl)-2,4-dihydro-3H-1,2,4-triazol-3-thiones. 5-(1,4(1,4)-Dibenzenacyclohexaphane-12-yl)-1,3,4-oxadiazol-2-amines were also synthesized in good yields via internal cyclization of the same paracyclophanyl-acylthiosemicarbazides. NMR, IR, and mass spectra (HRMS) were used to elucidate the structure of the obtained products. The X-ray structure analysis was also used as an unambiguous tool to elucidate the structure of the products.

X-Ray Structure Analysis and Spectroscopic Data of the Antibiotic 8-(Dichloroacetyl)-5-hydroxy-2,7-dimethyl-1,4-naphthoquinone from the Fungus Mollisia sp.*

1987 ◽  
Vol 42 (1-2) ◽  
pp. 1-3 ◽  
Author(s):  
Gabriela Weber ◽  
Thomas Hübner ◽  
Alfred Gieren ◽  
Johann Sonnenbichler ◽  
Tadeusz Kowalski ◽  
...  
Keyword(s):  
High Resolution ◽  
Structure Analysis ◽  
Spectroscopic Data ◽  
Mass Spectra ◽  
Nmr Spectra ◽  
X Ray ◽  
H Nmr

Abstract Mass spectra, X-ray data and high resolution 13C and 1H NMR spectra of 8-(dichloroacetyl)-5-hydroxy-2,7-dim ethyl-1,4-naphthoquinone are reported. The antibiotic active com pound was isolated from the fungus Mollisia sp.

Synthese und Röntgenstrukturanalyse von [Fe(η6-C6H4{1,3-(CH3)2})(η5 -C5(C6H5)5]+ [FeCl4]- / Synthesis and X-Ray Structure Analysis of [Fe(η6-C6H4{1 ,3 -(CH3)2})(η5-C5(C6H5)5]+ [FeCl4]-

1997 ◽  
Vol 52 (5) ◽  
pp. 573-576 ◽  
Author(s):  
Herbert Schumann ◽  
Alexander Lentz ◽  
Roman Weimann
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Structure Analysis ◽  
Mass Spectra ◽  
X Ray Diffraction ◽  
Space Group ◽  
X Ray

Abstract Fe[C5(C6H5)5](CO)2Br (1) reacts with m-xylene at 80°C followed by hydrolysis with diluted HCl in the presence of air, to give [Fe(η6-C6H4{1,3-(CH3)2})(775-C5(C6H5)5)]+[FeCl4]- (3). The 1H, 13CNMR and mass spectra as well as the single crystal X-ray diffraction analysis confirm the proposed sandwich cation structure. 3 crystallizes in the space group P 21/n with a = 984,0(1), b = 2201,0(7), c = 1684,9(2) pm, β = 91,94(1)° and V = 3647(1) x 10-30m3. The final refinement resulted in R = 0,054 for 2982 observed reflections with F0 ≥4σ (F0)

Pentamethylcyclopentadienyl Halfsandwich Complexes of Rhodium and Iridium Containing 1,1′-Ferrocene Dichalcogenido Ligands

1992 ◽  
Vol 47 (8) ◽  
pp. 1091-1098 ◽  
Author(s):  
Max Herberhold ◽  
Guo-Xin Jin ◽  
Arnold L. Rheingold ◽  
George F. Sheats
Keyword(s):  
Electron Impact ◽  
Structure Analysis ◽  
Mass Spectra ◽  
Nmr Spectra ◽  
Direct Interaction ◽  
Bimetallic Complexes ◽  
X Ray ◽  
New Compounds

A series of 12 bimetallic complexes Cp M(L)[(EC5H4)2Fe] (M(L) = Rh(PMe3), Ir(PMe3), Ir(PPh3) and Ir(CNtBu); E = S, Se, Te) has been synthesized from the dichlorides Cp M(L)Cl2. The new compounds have been characterized by their 1H, 13C and 31P NMR spectra in solution. The mass spectra indicate that the two-electron ligand L is preferentially eliminated upon electron-impact. Oxidation by AgBF4 to give ferrocenium-type cations also occurs readily. An X-ray structure analysis of CpRh(PMe3)[(SC5H4)2Fe] (la) confirms the presence of a 1,1′-ferrocene dithiolate ligand with parallel and ecliptic cyclopentadienyl rings. The long Rh ... Fe (430.4(1) pm) distance rules out any direct interaction between the rhodium center and the iron in the cavity of the ferrocene sandwich.

Halfsandwich cyclo-Pentasulfido and cyclo-Pentaselenido Complexes, (η5-C5Me5)M(NO)(E5) (E = S, Se; M = Cr, Mo, W)

1991 ◽  
Vol 46 (4) ◽  
pp. 500-506 ◽  
Author(s):  
Max Herberhold ◽  
Guo-Xin Jin ◽  
Walter Kremnitz ◽  
Arnold L. Rheingold ◽  
Brian S. Haggerty
Keyword(s):  
Structure Analysis ◽  
Chair Conformation ◽  
High Yield ◽  
Acetonitrile Solution ◽  
Chelate Ligand ◽  
Hydrogen Selenide ◽  
Chromium Complex ◽  
X Ray ◽  
Excess Sulfur ◽  
Hydrolysis Of

The reactions of the pentamethylcyclopentadienyl halfsandwich nitrosyl complexes Cp*Cr(NO)2I and Cp*M(NO)I2 (M = Mo, W) with either methanolic ammonium polysulfide solutions or hydrogen selenide solutions (generated by hydrolysis of Al2Se3) can be used to prepare cyc/o-pentachalcogenido compounds such as Cp*M(NO)(S5) (M = Cr (la), Mo (2a), W (3a)) and Cp*M(NO)(Se5) (M = Cr (lb), W (3b)). The chromium complex Cp*Cr(NO)(S5) (la) is also formed in high yield by photodecarbonylation of Cp*Cr(CO)2NO in acetonitrile solution in the presence of excess sulfur. An X-ray structure analysis of Cp*W(NO)(S5) (3 a) revealed a cyclo-S5 chelate ligand in the chair conformation and an almost linear nitrosyl group.

Zur Chemie der 1,3,5-Triaza-2-phosphorinan-4,6-dione. Teil X. Umsetzungen von 2-Hydro-1,3,5-trimethyl-1,3,5-triaza-2-oxo-2λ4- phosphorinan-4,6-dion mit Triazin-Derivaten sowie mit einigen Aldehyden / Chemistry of the 1,3,5-Triaza-2-phosphorinan-4,6-diones. Part X. Reactions of 2-Hydro-1,3,5-trimethyl-1,3,5-triaza-2-oxo-2λ4 -phosphorinan-4,6-dione with Triazine Derivatives and with Some Aldehydes

1995 ◽  
Vol 50 (12) ◽  
pp. 1833-1838 ◽  
Author(s):  
Ion Neda ◽  
Michael Farkens ◽  
Holger Thönnessen ◽  
Peter G. Jones ◽  
Reinhard Schmutzler
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Structure Analysis ◽  
Mass Spectra ◽  
Nmr Spectra ◽  
Glyoxylic Acid ◽  
Crystal Structure Analysis ◽  
Membered Ring ◽  
X Ray ◽  
Triazine Derivatives

The reactions o f 2-hydro-1,3,5-trim ethyl-1,3,5-triaza-2-oxo-2λ4 -phosphorinan-4,6-dione 1 with the triazine derivatives, 1,3,5-trimethyl- and 1,3,5-tribenzyl-hexahydro-1,3,5-triazine, are described. The reaction of three equivalents of 1 with one equivalent of the triazine derivative gave 2 and 3. Both compounds were characterized via their 1H, 13C, and 31P NMR spectra, mass spectra and, in the case of 2, by an X-ray crystal structure analysis, which showed an almost planar six-membered ring; hydrogen bonds of the form N-H···O link the molecules in centrosymmetric pairs. The reactions of 1 with the aldehydes glyoxylic acid, 2-hydroxybenzaldehyde and 3,4,5-trimethoxybenzaldehyde gave addition products. The C (:O) group o f the aldehyde is inserted into the P -H bond o f 1. The resulting compounds 4 ,5 and 6 were characterized through their 1H, 13C, and 31P NMR spectra, and mass spectra.

Das Isosterenpaar SiO/PN, I. Zur Isosterie von Perchlorcyclosiloxanen und Perchlorcyclophosphazenen. Schwingungsspektren und Röntgenstrukturanalyse von (Cl2SiO)3 und (Cl2SiO)4 / The SiO/PN Isoelectronic Pair, I. Perchlorocyclosiloxanes and Perchlorocyclophosphazenes. Vibrational Spectra and X-Ray Structure Analysis of (Cl2SiO)3 and (Cl2SiO)4

1991 ◽  
Vol 46 (7) ◽  
pp. 931-940 ◽  
Author(s):  
Ulrich Wannagat ◽  
Gabriele Bogedain ◽  
Adrian Schervan ◽  
Heinrich C. Marsmann ◽  
David J. Brauer ◽  
...  
Keyword(s):  
Structure Analysis ◽  
Vibrational Spectra ◽  
Mass Spectra ◽  
Ring Systems ◽  
X Ray

Hexachlorocyclotrisiloxane (2) and octachlorocyclotetrasiloxane (4) were prepared by reaction of SiCl4 with O2 at 955 °C. Their mass spectra are compared with those of the isoelectronic cyclophosphazenes. The vibrational spectra of 2 and 4 are very similar and closely related to that of (PNCl2)3, but clearly different from that of the puckered (PNCl2)4 molecule. The X-ray examination of 2 and 4 reveals planarity of the (SiO)n, n = 3 and 4 ring systems, with d(Si—O) on average 1.619(4) and 1.584(3) A, respectively.

Synthese und Kristallstruktur von 2,4-Di-tert-butyl-3-pentafluorphenyl-1,2,4,3-thiadiazaboretidin / Synthesis and Crystal Structure of 2,4-Di-tert-butyl-3-pentafluorophenyl-1,2,4,3-thiadiazaboretidine

1991 ◽  
Vol 46 (5) ◽  
pp. 625-628 ◽  
Author(s):  
Carl D. Habben ◽  
Regine Herbst-Irmer ◽  
Mathias Noltemeyer
Keyword(s):  
Crystal Structure ◽  
Structure Analysis ◽  
Mass Spectra ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Tert Butyl

Sulfur-diimides react with bismethylmercapto-pentafluorophenylboranes by reductive 1,3-cycloaddition of the NSN-sequence and formation of the 1,2,4,3-thiadiazaboretidines 2a,b. NMR (1H, 11B, 13C, 19F, 29Si), mass spectra and the results of the X-ray structure analysis of 2 a are reported and discussed.

Sign in / Sign up

Export Citation Format

Share Document