2955-79-5Relevant articles and documents
Photochemistries of oxadiazabicyclo[1.2.4]nonadiene, oxadiazabicyclo[2.2.3]nonadiene, and oxatriazabicyclo[2.2.3]nonadiene systems: Cycloreversion reactions to generate azepine or diazepine derivatives and isomerization reaction of oxadiazabicyclo[2.2.3]nonadiene system to oxadiazabicyclo[1.2.4]nonadiene system
Tomita, Tsunetaka,Ishiguro, Hiroyuki,Saito, Katsuhiro
, p. 141 - 144 (2007/10/03)
An irradiation of an oxadiazabicyclo[1.2.4]nonadiene derivative in acetonitrile with a low pressure mercury lamp afforded an 1H-azepine derivative. An irradiation of an oxadiazabicyclo[2.2.3]nonadiene derivative gave an oxadiazabicyclo[1.2.4]nonadiene derivative and an 1H-azepine derivative. On the other hand, a photo-reaction of an oxatriazabicyclo [2.2.3]nonadiene derivative generated a 1H-1,2-diazepine derivative. All these reactions are considered to proceed through the same type of reaction intermediate.
Cs2CO3 or CaO as promoters of ethyl N-{[(4-methylphenyl)sulphonyl]oxy}carbamate in amination reactions
Barani, Marco,Fioravanti, Stefania,Pellacani, Lucio,Tardella, Paolo A.
, p. 11235 - 11238 (2007/10/02)
Replacing triethylamine by heterogeneous inorganic bases makes it possible to aminate benzene or other nitrene acceptors, using the title reagent, previously reported to be scarcely reactive. Products of C-H insertion and/or those coming from intermediate aziridines are also obtained.
Improved amination by ethyl n-(4-nitrophenyl)sulphonyloxy carbamate in the presence of inorganic oxides or carbonates
Barani, Marco,Fioravanti, Stefania,Antonietta Loreto,Pellacani, Lucio,Tardella, Paolo A.
, p. 3829 - 3834 (2007/10/02)
Inorganic solid bases give rise to α-elimination reactions of NsONHCO2Et under easy and mild conditions without catalyst or ultrasounds. For several kinds of substrates, a comparison of yields and reaction times with previous methods is presented.
Electrophilic Aromatic N-Substitution by Ethoxycarbonylnitrenium Ion generated from Ethyl Azidoformate in the Presence of Trifluoroacetic Acid
Takeuchi, Hiroshi,Mastubara, Eiji
, p. 981 - 985 (2007/10/02)
Thermal reactions of ethyl azidoformate with aromatic compounds in the presence of trifluoroacetic acid (TFA) gave ethyl N-arylcarbamates.Toluene, nitrobenzene, or naphthalene was selectively attacked on the ortho- and para-positions, on the ortho- and meta-positions, or in the 1- and 2-positions, respectively.The yields were ca. twice as high as those for thermolysis ( a nitrene-azepine route) in the absence of TFA with the subsequent addition of TFA at room temperature.The positional selectivities for toluene and naphthalene were lower for the former thermolysis than for the latter.The reactivity of cyclohexane or toluene relative to benzene was greater in the latter thermolysis than the former.A Hammett plot with ρ - 1.7 was obtained for the formation of ethyl N-arylcarbamates in the former thermolysis in TFA-nitrobenzene (8:2 v/v); the value was more negative than that (-1.32) for the disappearance of substituted benzenes in the reaction with ethoxycarbonylnitrene.The results suggest that the thermolysis in the presence of TFA involves an electrophilic aromatic N-substitution by ethoxycarbonylnitrenium ion.
Investigation of Thermally Induced α-Deoxysilylation of Organosilylated Hydroxylamine Derivatives as a General Method for Nitrene Production
Chang, Young Hwan,Chiu, Fang-Ting,Zon, Gerald
, p. 342 - 354 (2007/10/02)
A variety of organosilylated hydroxylamine derivatives have been synthesized and studied as possible nitrene generators by thermally induced α-deoxysilylation: GN(OR')SiR3 GN + R'OSiR3, where G = EtO2C, ArCO, ArSO2, Me, H, and Ph2PO.The methods used to assess nitrene formation include trapping product characterization, substitutent variation, kinetic activation parameter measurements, Hammett studies, and solvent effects.While the latter two types of precursors were only briefly investigated because of their marked resistance to fragmentation, the combined data for the remaining compounds are consistent with the intermediacy of a nitrene.The existence of alternative deoxysilylation pathways is discussed in some cases, and for comparison with the nitrogen systems reported herein, kinetic activation parameters for α-deoxysilylation about carbon and silicon have been determined.
