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131.
Mudaris N. Dimukhametov Vladimir F. Mironov Dmitry B. Krivolapov Igor A. Litvinov Rashid Z. Musin 《Mendeleev Communications》2012,22(2):98-100
Keeping of O,O’-bis(2-benzylideneaminophenyl) phenylphosphonite in a CCl4 solution for 50 days resulted in its spontaneous rearrangement into 1,6,7-triphenyl-3,4:9,10-dibenzo-2,11-dioxa-5,8-diaza-1-phosphatricyclo[6.3.0.01,5]undeca-3,9-diene, a representative of spirophosphoranes with P–N bonds. 相似文献
132.
133.
Wieczorek-Ciurowa K. Gamrat K. Shirokov Ju. G. 《Journal of Thermal Analysis and Calorimetry》2003,72(1):323-328
A catalytic action of the mechanochemical products of copper hydroxocarbonate with calcium carbonate was investigated in n-butyl
alcohol oxidation tests. The solid products of high-energy milling were identified using thermogravimetry supplemented by
X-ray diffraction method. It was shown that the mechanical activation induces more effective tested catalyst because it promotes
the alcohol conversion at lower temperatures than that unmilled one.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
134.
Il'yas S. Nizamov Tat'yana P. Sorokina Alexey V. Matseevskii Dmitry B. Krivolapov Aidar T. Gubaidullin Igor A. Litvinov Boris E. Abalonin Elvira S. Batyeva Vladimir A. Alfonsov 《Heteroatom Chemistry》2000,11(4):287-291
10‐Propylthio‐5,10‐dihydrophenarsazine 2 was obtained by the reaction of 10‐chloro‐5,10‐dihydrophenarsazine 1 with propanethiol in the presence of triethylamine under mild conditions. The structure of 2 was established by X‐ray single crystal diffraction. The reaction of 2 with 2,4‐bis(ethylthio)‐1,3,2,4‐dithiadiphosphetane‐2,4‐disulfide 3 at room temperature affords a novel route to S‐10(5,10‐dihydrophenarsazine) S′‐ethyl‐S″‐propyltetrathiophosphate 4 . © 2000 John Wiley & Sons, Inc. Heteroatom Chem 11:287–291, 2000 相似文献
135.
Alexander V. Gusakov Arkady P. Sinitsyn Alejandro G. Berlin Nonna N. Popova Alexander V. Markov Oleg N. Okunev Dmitry F. Tikhomirov Mark Emalfarb 《Applied biochemistry and biotechnology》1998,75(2-3):279-293
A model microassay system was developed to measure indigo backstaining on cotton fabrics in the presence of enzymes on a small
laboratory scale. Backstaining indexes for 11 cellulase samples were measured, and the enzymes were ranked from lower to higher
backstaining. Two multienzyme cellulase preparations were separated into fractions using chromatofocusing on a Mono P column.
Adsorption ability and backstaining properties of purified enzyme fractions were studied. Evidence was obtained that protein
adsorption on cotton fabrics is a crucial parameter causing backstaining (both for crude cellulase samples and purified enzyme
components). 相似文献
136.
The superelectrophilic activation of N-aryl amides of 3-arylpropynoic acids by Bronsted superacids (CF3SO3H, HSO3F) or strong Lewis acids AlX3 (X=Cl, Br) results in the formation of 4-aryl quinolin-2(1H)-ones in quantitative yields. The vinyl triflates or vinyl chlorides may be formed as additional reaction products. The investigated amides in reactions with benzene give 4,4-diaryl 3,4-dihydroquinolin-2-(1H)-ones under the superelectrophilic activation. 4-Aryl quinolin-2(1H)-ones in POCl3 are converted into 4-aryl 2-chloroquinolines. 4-Fluorophenyl-4-phenyl 3,4-dihydroquinolin-2-(1H)-one give N-formylation products in a yield of 79% under the Vilsmeier–Haack reaction conditions. 相似文献
137.
Elena A. Shalamova Yeosan Lee Garam Chung Artem N. Semakin Jinho Oh Alexey Yu. Sukhorukov Dmitry E. Arkhipov Sema L. Ioffe Sergey E. Semenov 《Tetrahedron letters》2014
A general strategy for the assembly of previously unknown tris(β,β,γ-oximinoalkyl)amines from aliphatic nitro compounds and methyl vinyl ketone is described. The strategy involves N,N-bis(siloxy)enamines as key intermediates. The latter are accessible by double silylation of alkylnitro compounds. Nickel(II) and copper(II) complexes of tris(β,β,γ-oximinoalkyl)amines are prepared and structurally characterized. 相似文献
138.
Dr. Dmitry Katayev Kai F. Pfister Timo Wendling Prof. Dr. Lukas J. Gooßen 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(32):9902-9905
Various (hetero)arenecarboxylic acids were converted to the corresponding Daugulis amides and nitrated selectively in the ortho‐position in the presence of [CuNO3(PPh3)2] and AgNO2 at 50 °C. A microwave‐assisted saponification allows regenerating the carboxylate group within minutes, which may then be removed tracelessly by protodecarboxylation, or substituted by aryl‐ or alkoxy‐groups via decarboxylative cross‐coupling. 相似文献
139.
Palladium–N‐Heterocyclic Carbene (NHC)‐Catalyzed Asymmetric Synthesis of Indolines through Regiodivergent C(sp3)H Activation: Scope and DFT Study 下载免费PDF全文
Dmitry Katayev Dr. Evgeny Larionov Dr. Masafumi Nakanishi Dr. Céline Besnard Prof. Dr. E. Peter Kündig 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(46):15021-15030
Two bulky, chiral, monodentate N‐heterocyclic carbene ligands were applied to palladium‐catalyzed asymmetric C?H arylation to incorporate C(sp3)?H bond activation. Racemic mixtures of the carbamate starting materials underwent regiodivergent reactions to afford different trans‐2,3‐substituted indolines. Although this CAr?Calkyl coupling requires high temperatures (140–160 °C), chiral induction is high. This regiodivergent reaction, when carried out with enantiopure starting materials, can lead to single structurally different enantiopure products, depending on the catalyst chirality. The C?H activation at a tertiary center was realized only in the case of a cyclopropyl group. No C?H activation takes place alpha to a tertiary center. A detailed DFT study is included and analyses of methyl versus methylene versus methine C?H activation is used to rationalize experimentally observed regio‐ and enantioselectivities. 相似文献
140.
Pyranoside‐into‐Furanoside Rearrangement: New Reaction in Carbohydrate Chemistry and Its Application in Oligosaccharide Synthesis 下载免费PDF全文
Dr. Vadim B. Krylov Dmitry A. Argunov Dmitry Z. Vinnitskiy Stella A. Verkhnyatskaya Dr. Alexey G. Gerbst Dr. Nadezhda E. Ustyuzhanina Dr. Andrey S. Dmitrenok Prof. Dr. Johannes Huebner Prof. Dr. Otto Holst Prof. Dr. Hans‐Christian Siebert Prof. Dr. Nikolay E. Nifantiev 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(50):16516-16522
Great interest in natural furanoside‐containing compounds has challenged the development of preparative methods for their synthesis. Herein a novel reaction in carbohydrate chemistry, namely a pyranoside‐into‐furanoside (PIF) rearrangement permitting the transformation of selectively O‐substituted pyranosides into the corresponding furanosides is reported. The discovered process includes acid‐promoted sulfation accompanied by rearrangement of the pyranoside ring into a furanoside ring followed by solvolytic O‐desulfation. This process, which has no analogy in organic chemistry, was shown to be a very useful tool for the synthesis of furanoside‐containing complex oligosaccharides, which was demonstrated by synthesizing disaccharide derivatives α‐D ‐Galp‐(1→3)‐β‐D ‐ Galf ‐OPr, 3‐O‐s ‐lactyl‐β‐D ‐ Galf ‐(1→3)‐β‐D ‐Glcp‐OPr, and α‐L ‐ Fucf ‐(1→4)‐β‐D ‐GlcpA‐OPr related to polysaccharides from the bacteria Klebsiella pneumoniae and Enterococcus faecalis and the brown seaweed Chordaria flagelliformis. 相似文献