نتایج جستجو برای: dialkyl acetylenedicarboxylate daad
تعداد نتایج: 1661 فیلتر نتایج به سال:
Geometrically constrained dioxaphospholane rings were incorporated into a bis(phosphinimine)carbazole ligand (HL) in an effort to generate an ancillary ligand system that is capable of supporting reactive lutetium alkyl functionalities and resistant to cyclometalation reactivity. This new ligand was used to prepare a lutetium dialkyl species, LLu(CH2SiMe3)2; however, the complex exhibited low t...
The synthesis of the title compounds was carried out by reacting dicarboxylic acid chlorides with oximes in the presence of excess triethylamine. Disubstituted malonyl chlorides gave 2-alkenyl-4,4-dialkyl-3,5-isoxazolidinediones (8a-f) and 2,2'-ethylidene-bis[4,4-dialkyl-3,5-isoxazolidinedione]s (9a-f). Compounds 9 were formed from 8 and its N-unsubstituted 3,5-isoxazolidinedione decomposition ...
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...
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...
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...
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...
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...
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...
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...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید