Synthesis and characterization of phenyl-substituted C-phenyl-N-tert-butylnitrones and some of their radical adducts
摘要:
Synthesis of C-phenyl-N-tert-butylnitrone (PBN) and several of its analogues with substituents in the 2-, 3-, or 4-position on the phenyl ring is described. While a one-pot reduction/condensation method proved suitable for most compounds, it was necessary to prepare some examples by direct condensation or through oxidation of the appropriate imine. The H-1 NMR data for the 3-X- and 4-X-PBN's can be correlated with the Hammett equation. For the 3-X series DELTA-delta for the alpha-proton correlates best with sigma(+) and has a correlation coefficient of 0.90. For the 4-X series a dual substituent parameter equation using sigma(R)0 gives the best correlation with r = 0.99. The hyperfine splitting constants (hfsc's) of the HO. and HOO. adducts of several substituted PBN's are also included and their correlation with the Hammett equation is discussed.
Rh(III)- and Ir(III)-Catalyzed C–H Alkynylation of Arenes under Chelation Assistance
作者:Fang Xie、Zisong Qi、Songjie Yu、Xingwei Li
DOI:10.1021/ja501910e
日期:2014.3.26
Rh(III)- and Ir(III)-catalyzed, chelation-assisted C-H alkynylation of a broad scope of (hetero)arenes has been developed using hypervalent iodine-alkyne reagents. Heterocycles, N-methoxy imines, azomethine imines, secondary carboxamides, azo compounds, N-nitrosoamines, and nitrones are viable directing groups to entail ortho C-H alkynylation. The reaction proceeded under mild conditions and with controllable
Iridium(III)-Catalyzed C–H Amidation of Nitrones with Dioxazolones
作者:Xia Mi、Weisheng Feng、Chao Pi、Xiuling Cui
DOI:10.1021/acs.joc.9b00300
日期:2019.5.3
efficiently achieved through Ir(III)-catalyzed direct C–H amidation of nitrones with good to excellent yields and tolerance of broad functional groups. This reaction smoothly proceeded at roomtemperature in the absence of acid or base in a short reaction time. Carbon dioxide was generated as the sole byproduct, thus providing an environmentally benign amidation process. The title products could be efficiently
Substituent effects on ESR parameters of α-phenyl-N-tert-butylnitrone spin adducts. Resolution enhancement and mass spectrometry
作者:Kai Pan、Chiou-Rong Lin、Tong-Ing Ho
DOI:10.1002/mrc.1260310705
日期:1993.7
The combination of high‐performance liquid chromatography (HPLC) and ESR spectrometry was used to isolate the free radicals produced by the reaction of a Grignard reagent with 15 substituted α‐Phenyl‐N‐tert‐butylnitrone. Long‐range hyperfine splitting constants (hfsc) were obtained by the resolution enhancement method. Linear correlation studies between hfsc and Hammett σp constants are reported. Dual‐parameter
COMPOSITIONS AND METHODS OF INHIBITING RETINAL DEGENERATION
申请人:Anderson Robert E.
公开号:US20130225694A1
公开(公告)日:2013-08-29
Nitrone-based compositions are disclosed that may be utilized for the prevention and treatment of a variety of ophthalmic diseases or conditions where RPE65 protein isomerohydrolase is implicated. Methods of production and use of said nitrone-based compositions, as well as pharmaceutical and ophthalmic compositions containing same, are disclosed.