597-04-6Relevant articles and documents
NMR Spectroscopic Studies of Intermediary Metabolites of Cyclophosphamide. 2. Direct Observation, Characterization, and Reactivity Studies of Iminocyclophosphamide and Related Species
Boyd, Victoria L.,Summers, Michael F.,Ludeman, Susan Marie,Egan, William,Zon, Gerald,Regan, Judith B.
, p. 366 - 374 (1987)
4-Hydroxy-5,5-dimethylcyclophosphamide (6) was synthesized as a stable (to fragmentation) analogue of 4-hydroxycyclophosphamide (1).In anhydrous Me2SO-d6 (0.03 mol percent water), cis- and trans-6 were observed by multinuclear NMR spectroscopy to equlibrate with α,α-dimethylaldophosphamide (7) and 5,5-dimethyliminocyclophosphamide (8).Identification of 8 was based on 1H, 13C, and 31P chemical shifts, selective INEPT and two-dimensional NMR correlation experiments, and temperature-dependent equilibria data.The interconversion of cis-/trans-6 and -7 was also observed in lutidine buffer; 8 was not detected under the aqueous conditions.In Me2SO-d6, hydroxy metabolite 1 underwent dehydration to give iminocyclophosphamide (5), as evidenced by chemical shift data and a selective INEPT experiment.Concentrations of cis-/trans-1, aldophosphamide (2), and 5 were found to be temperature-dependent with higher temperatures favoring 2 and 5 in a reversible manner, thus indicating that 1/2/5 were interconverting.The addition of small amount of water to Me2SO-d6 solutions of imine 5 resulted in the immediate disappearance of its NMR signals.The role of imine 5 in the conversion of 1 to C-4 substituted analogues of 1 was elucidated for the formation of 4-cyanocyclophosphamide (3a) from 1 and sodium cyanate in lutidine buffer.
Five Roads That Converge at the Cyclic Peroxy-Criegee Intermediates: BF3-Catalyzed Synthesis of β-Hydroperoxy-β-peroxylactones
Vil, Vera A.,Gomes, Gabriel Dos Passos,Ekimova, Maria V.,Lyssenko, Konstantin A.,Syroeshkin, Mikhail A.,Nikishin, Gennady I.,Alabugin, Igor V.,Terent'Ev, Alexander O.
, p. 13427 - 13445 (2018/11/02)
We have discovered synthetic access to β-hydroperoxy-β-peroxylactones via BF3-catalyzed cyclizations of a variety of acyclic precursors, β-ketoesters and their silyl enol ethers, alkyl enol ethers, enol acetates, and cyclic acetals, with H2O2. Strikingly, independent of the choice of starting material, these reactions converge at the same β-hydroperoxy-β-peroxylactone products, i.e., the peroxy analogues of the previously elusive cyclic Criegee intermediate of the Baeyer-Villiger reaction. Computed thermodynamic parameters for the formation of the β-hydroperoxy-β-peroxylactones from silyl enol ethers, enol acetates, and cyclic acetals confirm that the β-peroxylactones indeed correspond to a deep energy minimum that connects a variety of the interconverting oxygen-rich species at this combined potential energy surface. The target β-hydroperoxy-β-peroxylactones were synthesized from β-ketoesters, and their silyl enol ethers, alkyl enol ethers, enol acetates, and cyclic acetals were obtained in 30-96% yields. These reactions proceed under mild conditions and open synthetic access to a broad selection of β-hydroperoxy-β-peroxylactones that are formed selectively even in those cases when alternative oxidation pathways can be expected. These β-peroxylactones are stable and can be useful for further synthetic transformations.
Development of metal-organic framework (MOF)-B12 system as new bio-inspired heterogeneous catalyst
Xu, Jing,Shimakoshi, Hisashi,Hisaeda, Yoshio
, p. 89 - 95 (2015/03/31)
Abstract A novel bimetal complex {Zn4Ru2(bpdc)4·4C2NH8·9DMF}n (1) (H2bpdc = 4,4′-biphenyldicarboxylic acid) was synthesized by the solvothermal method. The results of the X-ray crystallographic analysis revealed that 1 crystallizes in the orthorhombic Pna21 space group, which has a 3D 2-fold interpenetrated hex framework, with open channel sizes along the [010] direction of ca. 1.4 nm × 1.4 nm. The photosensitizer [Ru(bpy)3]2+ was adsorbed into the 1 to form Ru@MOF by cation exchanging. A cobalamin derivative (B12), heptamethyl cobyrinate, was also effectively immobilized on Ru@MOF, and the resulting hybrid complex, B12-Ru@MOF, exhibited a high reactivity for the dechlorination reaction of 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) under an N2 atmosphere by visible light irradiation in the solid state. The catalysis of B12-Ru@MOF can still reach more than a ca. 80% conversion after third recyclings. Furthermore, the heterogeneous catalyst, B12-Ru@MOF, was useful for the cobalamin-dependent reaction, such as the 1,2-migration of the acetyl group.
