Intramolecular 1,3-Dipolar Cycloaddition of Alkenylnitrones of the 4H-Imidazole Series: Synthesis of a New Nitroxide pH-Sensitive Spin Probe
作者:Denis Morozov、Igor Kirilyuk、Yuri Gatilov、Irina Bagryanskaya、Julya Bozhko、Denis Komarov、Igor Grigor’ev
DOI:10.1055/s-0029-1217109
日期:2010.1
A new method was used for the preparation of a pH-sensitive spin probe involving an intramolecular 1,3-dipolar cycloaddition - reductive isoxazolidine ring-opening - oxidation reaction sequence. 2-(2-Allyloxyphenyl)-5-R-4,4-dimethyl-4H-imidazole-3-oxides (R = Me, NMe2), prepared from 3-hydroxylamino-3-methylbutan-2-one, undergo intramolecular 1,3-dipolar cycloaddition upon heating in toluene. Treatment
一种新的方法被用来制备pH敏感的自旋探针,涉及分子内的1,3-偶极环加成-还原异恶唑烷开环-氧化反应序列。由3-羟基氨基-3-甲基丁烷-2-一制备的2-(2-烯丙氧基苯基)-5-R-4,4-二甲基-4 H-咪唑-3-氧化物(R = Me,NMe 2)在甲苯中加热时分子内的1,3-偶极环加成。用低价钛(LVT)试剂处理环加合物导致异恶唑烷环的NO键还原裂解,得到3'-羟甲基-5,5-二甲基-4-R-2,5-二氢螺[咪唑- 2,4'-苯并[]。胺(R = NMe 2)然后用MCPBA氧化为目标氮氧化物-3'-羟甲基-5,5-二甲基-4-二甲基氨基-2,5-二氢螺并[咪唑-2,4'-苯并吡喃] -1-氧基。 1,3-偶极环加成-低价钛-氮氧自由基-4 H-咪唑3-氧化物-pH敏感型自旋探针