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Over the recent decades, due to the special electronic characteristics and diverse reactivities, N-heterocyclic carbene (NHC) has received significant interest in organocatalyzed reactions. The formation of Breslow intermediates by NHC can convert into acyl anion equivalent, enolates, homoenolate, acyl azolium, and vinyl enolate etc., and the cycloaddition reactions of these species has attracted lots of attention. In this review, we focus on the summry of the development of NHC-activation of carbonyl carbon (or imine carbon) in situ, α-, β-, γ-, and beyond, and the cycloaddition reaction of these species.  相似文献   

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Lycorane is a pentacyclic core presented in alkaloids isolated from the Amaryllidaceae family of herbaceous flowering plants. Members of this class of natural products have shown to display important biological properties including analgesic, antiviral, and antiproliferative activities. This review presents the known synthetic routes toward α-, β-, γ-, and δ-lycoranes. α-(19 routes), β-(10 routes), γ-(38 routes), and δ-(6 routes).  相似文献   

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李钧  李云贵  王序 《化学学报》1980,38(6):581-583
本文报道用高锰酸钾在碱性溶液中氧化3-甲硫基-5-羟基-6-甲基-1,2,4-三嗪(3)以合成3-甲砜基-5-羟基-6-甲基-1,2,4-三嗪(13),后者在缓和条件下经亲核性取代反应制得一系列3-取代-5-羟基-6-甲基-1,2,4-三嗪类化合物(1)。为研究1,2,4-三嗪类化合物生理活性,拟合成(1)类化合物。3-巯基-5-羟基-6-甲基-1,2,4-三嗪(2),3-甲硫基-5-羟基6-甲基-1,2,4-三嗪(3),3-乙硫基-5-羟基-6-甲基-1,2,4-三嗪(4)及3-苄硫基-5-羟基-6-甲基-1,2,4-三嗪(5)均已合成[1,2]。  相似文献   

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The condensation of aminals of -dimethylaminoacrolein and 5-dimethylaminopenta-2,4-dienal with cyclic and acyclic 1,2-, 1,3-, 1,4-, 1,5-, and 1,6-diketones was studied. A series of previously unknown bis(,-dimethylaminopolyenyl)diketones was synthesized; their structures were established by means of1H and13C NMR spectroscopies. The electron absorption spectra were employed to study the mutual influence of -aminopolyene chromophores separated by two C=O groups.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1235–1241, July, 1993.  相似文献   

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本文给出了一条较好的制备5-丁基-9-苯基-4, 5, 6, 9-四氢苯并[d, e]恶唑[5, 4-g]-异喹啉-4, 6-二酮的反应路线, 即: 先由4-溴-1, 8-萘酐经亚胺化、硝化、水解和还原等反应制得N-丁基-3-硝基-4-羟基-1, 8萘酰亚胺, 再在硼酸的存在下, 将亚胺与苯甲酰氯反应可得到目标化合物。文中给出了该化合物的质谱、核磁共振、红外、紫外和荧光等光谱数据。  相似文献   

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文章描述了面包酵母将1, 4, 4α, 8α-四氢-1, 4-亚甲基萘-5, 8-二酮催化异构化为1, 4-二氢-5, 8-二羟基-1, 4-亚甲基萘, 而不是还原为相应的羟基化合物。  相似文献   

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