- Trimethylsilyl Pseudohalide Adducts of GaCl3 and B(C6F5)3
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Me3Si?X (X=CN, N3, OCN, and SCN) was treated with the Lewis acids GaCl3 and B(C6F5)3 in toluene yielding the desired adducts Me3Si?X→GaCl3 and Me3Si?X→B(C6F5)3. All synthesized adducts were isolated and completely characterized including single crystal structure elucidations. The different structures, thermodynamics of formation and charge transfer effects are discussed on the basis of experimental and theoretical data.
- Bl?sing, Kevin,Bresien, Jonas,Maurer, Steffen,Schulz, Axel,Villinger, Alexander
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supporting information
p. 1913 - 1920
(2021/05/10)
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- Borane Adducts of Hydrazoic Acid and Organic Azides: Intermediates for the Formation of Aminoboranes
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The reaction of HN3 with the strong Lewis acid B(C6F5)3 led to the formation of a very labile HN3?B(C6F5)3 adduct, which decomposed to an aminoborane, H(C6F5)NB(C6F5)2, above ?20 °C with release of molecular nitrogen and simultaneous migration of a C6F5 group from boron to the nitrogen atom. The intermediary formation of azide–borane adducts with B(C6F5)3 was also demonstrated for a series of organic azides, RN3 (R=Me3Si, Ph, 3,5-(CF3)2C6H3), which also underwent Staudinger-like decomposition along with C6F5 group migration. In accord with experiment, computations revealed rather small barriers towards nitrogen release for these highly labile azide adducts for all organic substituents except R=Me3Si (m.p. 120 °C, Tdec=189 °C). Hydrolysis of the aminoboranes provided C6F5-substituted amines, HN(R)(C6F5), in good yields.
- Bl?sing, Kevin,Bresien, Jonas,Labbow, René,Michalik, Dirk,Schulz, Axel,Thomas, Max,Villinger, Alexander
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supporting information
p. 6540 - 6544
(2019/04/10)
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- Synthesis, DNA-binding abilities and anticancer activities of triazole-pyrrolo[2,1-c][1,4]benzodiazepines hybrid scaffolds
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We synthesized a new series of PBD-hybrid derivatives having tethered triazoles and investigated for their cytotoxicity. The studies indicated that cis-olefin compounds induce higher cytotoxicity with increase in the G1 cell cycle phase compared with the trans-compounds. Quantitative RT-PCR assay indicated that compounds (16a-d) induced G1 phase arrest through down-regulation of cyclin D1 and up-regulation of p21, p27, and p53 mRNA expressions. Compounds 16a-d induced A375 early apoptosis as detected by flow cytometry after double-staining with annexin V and propidium iodide. Moreover, the Western blot analysis showed that A375 treated by compounds (16a-d) resulted in decreased levels of Bcl-2 and Bcl-xL, increased levels of Bax and Bad, and caspase/PARP degradation to identify apoptotic cells.
- Chen, Chung-Yu,Lee, Pei-Hua,Lin, Yong-Yong,Yu, Wen-Ting,Hu, Wan-Ping,Hsu, Chia-Chen,Lin, Ying-Ting,Chang, Long-Sen,Hsiao, Cheng-Tien,Wang, Jeh-Jeng,Chung, Mei-Ing
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p. 6854 - 6859
(2014/01/06)
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- METHOD FOR PRODUCING TRIMETHYLSILYL AZIDE
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The present invention relate to a method for producing a trimethylsilyl azide represented by the formula (3): ????????(CH3)3SiN3?????(3) which comprises reacting a trimethylsilyl chloride represented by the formula (1): ????????(CH3)3SiCl?????(1) with an inorganic salt of hydrogen azide represented by the formula (2): ????????M(N3)n?????(2) wherein M represents an alkali metal or an alkaline earth metal, and n represents 1 or 2, in the presence of a phase-transfer catalyst and an organic solvent having a high boiling point.
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Page/Page column 4
(2008/06/13)
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- Process for preparation of penam derivatives
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The invention relates to novel processes for preparing penam derivatives, such as Tazobactam and derivatives thereof. The processes according to the invention encompass procedures for the protection and deprotection of the carboxylic group as well as for the oxidation of the sulphur moiety of penam derivatives. Additionally, the present invention relates to new intermediates for the production of penam derivatives, allowing the desired penam-derivatives to be formulated with high purity and in good yields.
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Page/Page column 8
(2008/06/13)
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- Process for preparation of penam derivatives
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The invention relates to novel processes for preparing penam derivatives, such as Tazobactam and derivatives thereof. The processes according to the invention encompass procedures for the protection and deprotection of the carboxylic group as well as for the oxidation of the sulfur moiety of penam derivatives. Additionally, the present invention relates to new intermediates for the production of penam derivatives, allowing the desired penam-derivatives to be formulated with high purity and in good yields.
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Page/Page column 4-5
(2008/06/13)
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- The chemistry of N,N-bis(siloxy)enamines. Part 8. A general method for the preparation of α-azido oximes from aliphatic nitro compounds
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A new strategy for the synthesis of α-azido oximes from aliphatic nitro compounds via interaction of N,N-bis(silyloxy)enamines with trimethylsilylazide was realized to give the target products with good yields.
- Sukhorokov, Alexey Yu.,Bliznets, Igor V.,Lesiv, Alexey V.,Khomutova, Yulija A.,Strelenko, Yuriy A.,Ioffe, Sema L.
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p. 1077 - 1082
(2007/10/03)
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- A study on the haterogeneous reaction of trialkylsilyl chlorides with inorganic salts and monocarboxylates catalysed by PEG400
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The important and useful trialkylsilyl pseudohalides R3SiX, where X=NCS, NCO, N3 or CN and R=methyl or ethyl, and trimethylsilyl monocarboxylates, where X=RCOO, were readily prepared in high yields by nucleophilic substitution of R3SiCl with X ions provided by NaX or KX at room temperature catalysed by PEG400 and zinc iodide. The reactions of trimethylsilyl chloride with some metal oxysalts were also studied for the first time.
- Du, Yun-Fei,Cao, Yu-Qing,Dai, Zhi,Chen, Bao-Hua
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p. 223 - 225
(2007/10/03)
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- An ESR study on structures of a series of silylnitrenes
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Structures of a series of silylnitrenes formed from silyl azides were investigated by means of ESR. γ-Irradiation and photo-illumination of all the silyl azides resulted in the formation of triplet states even for those having two or three Si-N3 groups in a molecule. ESR spectra of the silylnitrenes exhibited a part of the fine structure at around 820 mT. All the silyl azides studied gave nearly identical D-values (ca. 1.5cm-1) and much larger than those in phenylnitrenes. The results suggested that electron spins are localized in the nitrogen p-orbitals to a large extent and was interpreted in terms of a mono-silane linkage of nitrene, -Si-N:, i.e., interrupting spin delocalization.
- Itagaki, Yoshiteru,Iseoka, Takashi,Iida, Toshiyuki,Ohshita, Joji,Shiotani, Masaru,Kunai, Atsutaka
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p. 249 - 254
(2007/10/03)
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- Herbicidal 1-aryl-4-substituted-1,4-dihydro-5H-tetrazol-5-ones and sulfur analogs thereof
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Herbicidal aryltetrazolinones and thiones of the formula STR1 in which W is oxygen or sulfur; R is alkyl, fluoroalkyl, alkenyl, haloalkenyl, cyanoalkyl, alkylthioalkyl, haloalkoxyalkyl, trifluoromethylthio or alkoxyalkyl; one of X1 and X2 is fluorine, chlorine, or bromine and the other is fluorine, chlorine, bromine, alkyl, nitro or haloalkyl; and Z is a group selected from a variety of substituents including 2-propynyloxy as disclosed and exemplified.
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- Nucleophilic Substitution Reactions of Alkyl Halides By Using New Polymer-Supported Reagents Containing Hemin
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A new polymer reagent consisting of hemin, divinylbenzene, and 2-methyl-5-vinylpyridine was synthesized by suspension copolymerization.Substitution reactions of primary, secondary, and tertiary alkyl halides with the hemin copolymer combined with cyanide, azide, and thiocyanate ions were given satisfactory yields.This reaction mechanism was revealed to be a SNi type on the basis of stereochemical study.The hemin copolymer was not only a polymer-supported reagent with functional capabilities, but also served to separate the product from the reaction mixture.
- Saito, Kiyoshi,Harada, Kaoru
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p. 2562 - 2566
(2007/10/02)
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- Selective Formation of Alkyl Azides Using Trimethylsilyl Azide and Carbonyl Compounds
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Whereas tin(II) chloride, or zinc chloride, catalyzed reaction of trimethylsilyl azide (TMSA) with carbonyl compounds gave gem-diazides 3, a catalytic amount of sodium azide/15-crown-5 promoted an addition reaction of TMSA toward these compounds to give α-siloxy azides 2 exclusively.A stereoelectronic effect was found to be important for these reactions.
- Nishiyama, Kozaburo,Yamaguchi, Tomoko
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p. 106 - 108
(2007/10/02)
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- EXPERIMENTAL STUDIES OF THE ANOMERIC EFFECT. PART 2 RING INVERSION AND NITROGEN INVERSION EQUILIBRIA IN CIS-DECAHYDROQUINAZOLINES
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The positions of conformational equilibria due to the double ring inversion in cis-decahydroquinazoline (7-->//07-->8 1.08 kcal mol-1; -ΔG09-->10 1.10 kcal mol-1) for the conformation which would allow the lone pairs on N(1) and N(3) to lie on the hindered 'inside' face of the molecules.However, the values of 3J(CHNH) coupling constants for both cis-decahydro-3-methylquinazoline (10) and cis (4aH, 8aH) cis (2H, 8aH)-decahydro-2,3-dimethylquinazoline (14) show that the N-inversion equilibrium at N(1) prefers the conformation in which N(1)-H is 'inside' (axial), and N(1)-lone pair equatorial, thus demonstrating the ability of the anomeric effect to outweigh steric repulsions.
- Booth, Harold,Khedhair, Khedhair A.,Al-Shirayda, Hatif A. R. Y.
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p. 1465 - 1476
(2007/10/02)
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- REACTIONS OF TRIMETHYLSILYL AZIDE WITH ALDEHYDES: FACILE AND CONVENIENT SYNTHESES OF DIAZIDES, TETRAZOLES, AND NITRILES
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The reactions of trimethylsilyl azide (TMSA) with various aldehydes were found to be versatile procedures for the synthesis of gem- and 1,3-diazides, tetrazoles, and nitriles, whose formation was varied by controlling the quantities of TMSA, catalyst, and the reaction conditions.
- Nishiyama, Kozaburo,Oba, Makoto,Watanabe, Akio
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p. 693 - 700
(2007/10/02)
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- Storage of Silan- and Germanimines Me2E=NR (E = Si, Ge) by Way of Sila- or Germadihydrotetrazoles
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Silan- and germanimines Me2E=NR (1, 2) ntBu3-n, SiPh3, EMe2N(SiMe3)2> react with azidoalkanes or -silanes R'N3 ntBu3-n, SiPh3, SiMe2N(SiMe3)2> by cycloaddition to form sila- or germatetrazoles 5, 6 (in addition, insertion products of Me2E=NR in the R'N bond of the azides and others are formed in some cases).The sila- or germadihydrotetrazoles decompose at raised temperatures in a first-order reaction, reversing their formation by cycloreversion into azides R'N3 or RN3 and imines Me2E=NR or Me2E=NR' (rate constants: Table 1).Consequently, azides operate as stores for silan- and germanimines.The unsaturated systems are formed only as short-lived intermediates.Their stabilization, as a rule, takes place by dimerization and/or insertion of the imines into the RN or R'N bond of the azides, formed as well by thermolysis of dihydrotetrazoles.
- Wiberg, Nils,Karampatses, Petros,Kim, Chung-Kyun
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p. 1213 - 1222
(2007/10/02)
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- Partially Substituted Tetrazenes (Me3E)nN4H4-n (E = Si, Ge, Sn): Preparation, Characterization, and Thermolysis
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Partially substituted tetrazenes (Me3E)nN4H4-n (E = Si, Ge, Sn) can be prepared by protolysis of higher substituted tetrazenes (Me3E)oN4H4-o (o > n) or by silylation, germylation, or stannylation of lower substituted tetrazenes (Me3E)mN4H4-m (m 140 deg C1/2 = 3/4 h), of (Me3Si)2N-N=N-NH2 to Me3SiN3 and Me3SiNH2 (concentrated solution; τ40 deg C1/2 ca. 1/4 h), and of (Me3Si)HN-N=N-NH(SiMe3) to N2 and (Me3Si)2N-NH2 (dilute solution; τ140 deg C1/2 > 1 h) or to HN3 and (Me3Si)2NH (concentrated solution; τ140 deg C1/2 1 h).
- Wiberg, Nils,Meyers, Rene,Vasisht, Sham Kumar,Bayer, Heiner
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p. 2886 - 2899
(2007/10/02)
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- Darstellung silylierter Lithium-tetrazenide
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Reactions of butyllithium with tris- or bis(trimethylsilyl)tetrazene, (Me3Si)3N4H or (Me3Si)2N4H2, lead to tetrazenides 1 - 3 which are sensitive in hydrolysis and thermolysis as well as against oxygen.Reactions (1) - (6) refer to their modes of thermolysis.
- Wiberg, Nils,Bayer, Heiner,Vasisht, Sham Kumar
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p. 2658 - 2660
(2007/10/02)
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- Tetrasubstituted Tetrazenes (Me3E)2N-N=N-N(EMe3)2 (E = Si, Ge, Sn): Reactivity
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By substitution of the silyl, germyl, or stannyl groups, (Me3Si)2N-N=N-N(SiMe3)2 (1) reacts with variable amounts of trifluoroacetic acid to form (Me3Si)4-nN4Hn, (Me3Ge)2N-N=N-N(GeMe)2 (2) with variable amounts of methanol to form (Me3Ge)4-nN4Hn, and (Me3Sn)2N-N=N-N(SnMe3)2 (3) with variable amounts of trimethylchlorosilane to give (Me3Sn)4-nN4(SiMe3)n (n = 1-4).The reaction of 1 with benzenesulfonyl isocyanate leads by substitution and cyclization to silylated 5-hydroxytetrazole 12.Substitution in connection with thermolysis of the substitution products formed is found in the reaction of 1 with methanol, aluminium chloride, or nitrosyl chloride and in the reaction of 3 with trimethylstannane, acetone, or nitrosobenzene.By oxidation of 1 with chlorine, bromine, or p-benzoquinone and of 3 with p-benzoquinone or oxygen, all tetrazene nitrogen is envolved.The reduction of 1 with hydrogen or alkali metals leads to nitrogen and (Me3Si)2NH or (Me3Si)2NM.
- Wiberg, Nils,Bayer, Heiner,Vasisht, Sham Kumar,Meyers, Rene
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p. 2916 - 2927
(2007/10/02)
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- Facile preparation of silyl azides with dipolar aprotic solvents
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The reaction of sodium azide with chlorosilanes in hexamethylphosphoric triamide or dimethylformamide at room temperature affords a high yield preparation of silyl azides, e.g. Me3SiN3,Me2Si(N3)2, PhMeSi(N3)2 and Ph2Si(N3)2. For characterization, the azides may be converted to silyphosphiimies, R3Si-N=PPh3.
- S. Washburne, Stephen,R. Peterson Jr., William
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p. 153 - 156
(2007/10/05)
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