نتایج جستجو برای: dialkyl acetylenedicarboxylate

تعداد نتایج: 1366  

Journal: :The Journal of organic chemistry 2009
Yu Chen Chul-Hee Cho Feng Shi Richard C Larock

3-Sulfenyl- and 3-selenylindoles are readily synthesized by a two-step process involving the palladium/copper-catalyzed crossing coupling of N,N-dialkyl-ortho-iodoanilines and terminal alkynes and subsequent electrophilic cyclization of the resulting N,N-dialkyl-ortho-(1-alkynyl)anilines with arylsulfenyl chlorides or arylselenyl chlorides. The presence of a stoichiometric amount of n-Bu(4)NI i...

Journal: :International journal of toxicology 2016
Monice M Fiume Bart Heldreth Wilma F Bergfeld Donald V Belsito Ronald A Hill Curtis D Klaassen Daniel C Liebler James G Marks Ronald C Shank Thomas J Slaga Paul W Snyder F Alan Andersen

The Cosmetic Ingredient Review (CIR) Expert Panel (Panel) assessed the safety of 8 dialkyl sulfosuccinate salts for use in cosmetics, finding that these ingredients are safe in cosmetics in the present practices of use and concentration when formulated to be nonirritating. The dialkyl sulfosuccinate salts primarily function as surfactants in cosmetics. The Panel reviewed the new and existing av...

Journal: :The Journal of organic chemistry 2004
Pinjing Zhao Brett L Lucht Sarita L Kenkre David B Collum

Mechanistic studies of the enolization of 2-methylcyclohexanone mediated by lithium hexamethyldisilazide (LiHMDS; TMS(2)NLi) solvated by hindered dialkyl ethers (ROR') are described. Rate studies using in situ IR spectroscopy show that enolizations in the presence of i-Pr(2)O, 2,2,5,5-tetramethyltetrahydrofuran, and cineole proceed via dimer-based transition structures [(TMS(2)NLi)(2)(ROR')(ket...

2013
N. Selvakumaran A. Pratheepkumar Edward R.T. Tiekink R. Karvembu

Six square planar Ni(II) complexes of 3,3-dialkyl/aryl-1-benzoylthiourea derivatives have been synthesized and characterized by elemental analyses, and electronic, FT-IR and NMR spectroscopic techniques. A cis-O2S2 disposition in complexes 3, 4 and 5 was confirmed by single crystal X-ray crystallography. The cytotoxicity of the 3,3-dialkyl/aryl-1-benzoylthiourea molecules and their complexes wa...

Journal: :Beilstein Journal of Organic Chemistry 2006
Babak Kaboudin Fatemeh Farjadian

Reactions of O,O'-dialkyl thiophosphoric acids with alkyl halides, in the presence of a base, provide a direct synthetic route to phosphorothioates via O,O'-dialkyl thiophosphate anion formation. Studies on the reaction of ambident nucleophile ammonium O,O'-diethyl thiophosphate with benzyl halides and tosylate in different solvents show that only S-alkylation is obtained. Reaction of this ambi...

Journal: :Journal of the American Chemical Society 2013
Alexander P Pulis Daniel J Blair Eva Torres Varinder K Aggarwal

Simple, secondary 2,4,6-triisopropyl benzoates (TIB esters) and secondary dialkyl N,N-diisopropyl carbamates have been reported to be resistant to deprotonation by strong bases. We have found that the combination of sBuLi (1.6 equiv) and TMEDA (6 equiv) in CPME at -60 °C enables deprotonation of unactivated secondary dialkyl TIB esters, but not the carbamates. These carbanions were reacted with...

Journal: :Toxicon : official journal of the International Society on Toxinology 2009
Li Chen Henry Y Fadamiro

The venom of the red imported fire ant, Solenopsis invicta, is dominated by trans stereoisomers of 2,6-dialkylpiperidines. cis Stereoisomers of alkaloids in the venom of S. invicta were separated from trans stereoisomers by using silica gel short column chromatography and identified by coupled gas chromatography mass spectrometry (GC-MS). Seven pairs of cis and trans sterecoisomers were identif...

2011
Heiko Ihmels Jia Luo

Dibenzobarrelene derivatives, that are annelated with a pyrrolinium unit [N,N-dialkyl-3,4-(9',10'-dihydro-9',10'-anthraceno-3-pyrrolinium) derivatives], undergo a photo-induced di-π-methane rearrangement upon triplet sensitization to give the corresponding cationic dibenzosemibullvalene derivatives [N,N-dialkyl-3,4-{8c,8e-(4b,8b-dihydrodibenzo[a,f]cyclopropa[cd]pentaleno)}pyrrolidinium derivati...

2005
Akio Yamamoto Takakazu Yamamoto Sanshiro Komiya Fumiyuki Ozawa

Square planar dialkyl complexes of nickel, palladium and platinum exhibit intriguing difference in their reactivities. Thermolysis pathways of these dialkyls vary depending on the metal, ligands, alkyl groups, geometry as well as the presence or absence of added ligand. Kinetic studies on the thermolysis and trans-cis isomerizations of PdR,L2 (L = tertiary phosphine) complexes showed involvemen...

2008
Bernd Wrackmeyer Ezzat Khan Rhett Kempe

Protodeborylation of triorganoboranes, usually carried out under mild reaction conditions using an excess of acetic acid, affords 1,5-dialkyl-3,7-dimethyl-4,8,9-trioxa-2,6-dioxonia-1,5-diboratabicyclo [3.3.1]nona-2,6-dienes OB(R)OC(Me)OB(R)OC(Me)O [1 (R = Et), 2 (R = cyclooctyl)]. Acetoxy(dialkyl)boranes and di(acetoxy)alkylboranes were not formed in an appreciable amount. Compounds 1 and 2 wer...

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