2,2,3,3-四甲基-7a-R-1,2,3,7a-四氢咪唑并[1,2 - b ]异恶唑-6,7-二羧酸酯衍生物的异常热转变
摘要:
二甲基2,2,3,3-四甲基-7a-R-1,2,3,7a-四氢咪唑并[1,2- b ]-异恶唑-6,7-二羧酸酯衍生物沿两种竞争路线进行热重排生成2-(2-R-4,5-二氢-1 H -3λ-5-咪唑-3-亚甲基)-3-氧代琥珀酸酯衍生物和(或)二甲基-2-氧代-3-(1- R-咪唑啉丁-2-亚基)琥珀酸酯。在N-未取代的衍生物的情况下,后者进行分子内环化,生成甲基5,6-二氧-1--1-R-2,3,5,6-四氢-1 H-吡咯并[1,2 - a ]咪唑-7 -羧酸盐。
Mechanism of the migration of the substituent in 1,2,3,7a-tetrahydroimidazo[1,2-b]isoxazole derivatives
作者:N. V. Chukanov、S. A. Popov、T. N. Drebushchak、V. A. Reznikov
DOI:10.1007/s11172-010-0318-6
日期:2010.9
intramolecular rearrangements by two main pathways. One rearrangement affords azomethine ylide derivatives. Another rearrangement leads to the migration of the substituent from position 7a to the nitrogen atom. The rate constants of these reactions were determined. Quantum chemical calculations by the DFT method were carried out. Based on the data for the migration of the substituent, the concerted mechanism
Transformation of 1,2,3,7a-tetrahydroimidazo[1,2-b]isoxazole derivatives into isoxazoles
作者:N. V. Chukanov、S. A. Popov、G. V. Romanenko、V. A. Reznikova
DOI:10.1007/s11172-007-0185-y
日期:2007.6
The reactions of 1,2,3,7a-tetrahydroimidazo[1,2-b]isoxazolederivatives with electrophilic reagents, such as protic acids, benzoyl chloride, BF3, and bromine, produce isoxazole, 2,2,3,3-tetramethylaziridine, and 2,3,3-trimethylpropen-2-ylamine derivatives.
1,3-Dipolar cycloaddition reaction of 4,5-dihydro-1<i>H</i>-imidazole 3-oxides with alkynes
作者:Sergey A. Popov、Nikita V. Chukanov、Galina V. Romanenko、Tatjana V. Rybalova、Yuri V. Gatilov、Vladimir A. Reznikov
DOI:10.1002/jhet.5570430206
日期:2006.3
4,5-Dihydro-1H-imidazole3-oxides bearing different substituents at positions 1 and 2 of the heterocycle were shown to react with a wide range of acceptor-substituted alkynes forming corrsponding cycloadducts - derivatives of 1,2,3,7a-tetrahydroimidazo[1,2-b]isoxazole. High regioselectivity of this process stipulated by conjugation of the nitrogen atom with the nitrone group was revealed.
显示在杂环的1和2位带有不同取代基的4,5-二氢-1 H-咪唑3-氧化物可与各种受体取代的炔烃反应形成相应的环加合物-1,2,3,7a衍生物-四氢咪唑并[1,2- b ]异恶唑。揭示了该过程的高区域选择性,这是由氮原子与硝酮基团的缀合所规定的。
The unusual thermal transformations of the dimethyl 2,2,3,3-tetramethyl-7a-R-1,2,3,7a-tetrahydroimidazo[1,2-b]isoxazole-6,7-dicarboxylate derivatives
作者:Nikita V. Chukanov、Sergey A. Popov、Galina V. Romanenko、Vladimir A. Reznikov
DOI:10.1016/j.tet.2008.05.038
日期:2008.7
3-tetramethyl-7a-R-1,2,3,7a-tetrahydroimidazo[1,2-b]-isoxazole-6,7-dicarboxylate derivatives were shown to undergo thermal rearrangement along two competing routes giving rise to dimethyl 2-(2-R-4,5-dihydro-1H-3λ-5-imidazol-3-ylidene)-3-oxosuccinate derivatives and (or) dimethyl-2-oxo-3-(1-R-imidazolidin-2-ylidene)succinates. The latter undergoes intramolecular cyclization producing, in case of N-unsubstituted
二甲基2,2,3,3-四甲基-7a-R-1,2,3,7a-四氢咪唑并[1,2- b ]-异恶唑-6,7-二羧酸酯衍生物沿两种竞争路线进行热重排生成2-(2-R-4,5-二氢-1 H -3λ-5-咪唑-3-亚甲基)-3-氧代琥珀酸酯衍生物和(或)二甲基-2-氧代-3-(1- R-咪唑啉丁-2-亚基)琥珀酸酯。在N-未取代的衍生物的情况下,后者进行分子内环化,生成甲基5,6-二氧-1--1-R-2,3,5,6-四氢-1 H-吡咯并[1,2 - a ]咪唑-7 -羧酸盐。