112175-88-9Relevant academic research and scientific papers
Photogeneration of Highly Electrophilic Benzoylketene from Dibenzoyldiazomethane in Aqueous Solvents: Reaction with Amino Acids and DNA Cleavage
Nakatani, Kazuhiko,Shirai, Junya,Tamaki, Ryo,Saito, Isao
, p. 5363 - 5366 (2007/10/02)
Photoirradiation of dibenzoyldiazomethane in the presence of amino acid derivatives in aqueous solutions efficiently produced the addition products through a reaction with photogenerated benzoylketene.Efficient DNA cleavage was observed with a dibenzoyldiazomethane derivative, possessing a cationic side chain under photoirradiation conditions.
Formation of Polycyclic Dimers from Vinyl Nitroxides and Their Dissociation and Isomerization
Aurich, Hans Guenter,Bubenheim, Otto,Kessler, Wilfried,Mogendorf, Klaus-Dieter
, p. 4997 - 5004 (2007/10/02)
The ambiphilic vinyl nitroxides (VN) 6 dimerize, affording either tricyclic dimers (TRI-DI) 8 or bicyclic dimers (BI-DI) 7.Formation of 8 is rationalized by C-C bond formation followed by an intramolecular (3 + 2 + 2) cycloaddition involving one nitrone and two carbonyl groups, whereas 7 must arise from O-C bond formation followed by an intramolecular (3 + 2) cycloaddition of nitrone and alkene moiety.Since the BI-DIs 7 are the thermodynamically more stable dimers, the course of the reaction depends on the question of whether it is possible to overcome the activation barrier for its formation.The crucial reaction step, the 1,3 dipolar cycloaddition involving the nitrone and alkene moiety, is favored by N-phenyl substitution and retarded by N-tert-butyl substitution of the nitrone group.Thus, BI-DIs 7 arise from N-phenyl-substituted VNs, whereas VNs with R1 = tert-butyl yield TRI-DIs 8 at room temperature.Most of the TRI-DIs 8 dissociate at room temperature or slightly elevated temperatures.Dissociation is favored either by steric congestion of 8 or by enhanced stabilization of the acyl group R3CO of the VNs 6.Tetracyclic dimers (TET-DI) 12 arise from TRI-DIs 8 in refluxing methanol or in the presence of acids at room temperature.Isomerization in aprotic solvents in the absence of acids requires higher temperatures.Under these conditions formation of TET-DIs 12 is frequently accompanied by formation of BI-DIs 7 which must be formed via the VNs 6.
N,O-Heterocycles. Part 18. Regiochemistry and Site Selectivity of N-Alkylhydroxylamine Addition to 2,3-Diphenylcyclopropenone
Liguori, Angelo,Sindona, Giovanni,Uccella, Nicola
, p. 961 - 967 (2007/10/02)
This paper evaluates the reactivity of 2,3-diphenylcyclopropenone towards N-alkylhydroxylamines and 2,2-dimethylnitrosoethane (4).CPO preferentially affords 2-methyl-4,5-diphenylisoxazol-3(2H)-one when it is treated with N-methylhydroxylamine, while treatment with higher homologues gives rise to acyclic products. 3,4-Diphenyl-2-t-butylisoxazol-5(2H)-one is formed when substrate (1) reacts with (4).The formation of the products is strongly affected by the oxidizing power of the α- nucleophiles which drive the population of the observed reaction channels from the 1,2 or 1,4 adducts initially formed.A general mechanism is proposed whereby isoxazolones are formed from CPO and both nitroso compounds and hydroxylamine.
