【摘 要】
:
Heterocycles such as chromans and chromenes are important classes of benzopyran derivatives to be found in many natural products and synthetic molecules exhibiting unique biogical and pharmacological
【机 构】
:
State Key Laboratory and Institute of Elemento-organic Chemistry,Collaborative Innovation Center of
论文部分内容阅读
Heterocycles such as chromans and chromenes are important classes of benzopyran derivatives to be found in many natural products and synthetic molecules exhibiting unique biogical and pharmacological activities1.Despite the fact that subclass of 4H-chromenes are important as core structures featured in a great number of biologically active molecules,efficient catalytic asymmetric methods allowing the rapid access to these heterocycles are still rare2.We have developed a concise synthetic approach to 3-spiropyrazolone benzopyran with high stereoselectivity and diastereoselectivity by using bifunctional catylysts3.Future studies will focus on the development of related transformations,such as the application of this methodology toward the synthesis of molecules with biological and medicinal interest.
其他文献
咪唑及其衍生物是构建配位化合物的优良配体 [1]。这类配合物在功能材料领域 (磁学、非线性光学、催化性能) 有着潜在的应用价值 [2]。本文合成了一个咪唑衍生物:1-(苯并三氮唑-1-甲基)-1-(2-甲基咪唑),用该化合物作为配体与过渡金属盐反应,得到了四个金属配合物,[Zn(bmmi)4]·2NO3 (1),[Cd(bmmi)(SO4)(2CH3OH)(H2O)]n (2),{[Ag(bmmi
双功能催化剂近年来发展十分迅速,在许多反应类型中都表现出很好的催化活性和立体选择性,特别是在手性药物和天然产物的合成中都发挥着重要的作用.通过Lewis/Br?nsted 酸和Lewis/Br?nsted 碱的合理配置和协同催化作用,双功能催化剂对参加反应的亲电试剂和亲核试剂能够同时进行活化.通过这种双活化作用机制,不仅有利于提高反应速度和产物的立体选择性,而且有利于拓展不对称催化反应的底物类型和
N-Sulfinyl imines are versatile intermediates in the asymmetric synthesis of chiral amines such as α-branched amines,α,β-dibranched amines,α-andβ-amino acids,aziridines,andα-andβ-aminophosphonic acids
本文成功的采用一步法合成磁性大孔/介孔复合孔生物活性玻璃(MMBG),主要采用廉价的盐刻蚀技术作为大孔模板,于此同时非离子型三嵌段共聚物P123 不仅作为介孔模板剂,而且作为还原剂,在P123 高温分解过程中铁源被还原成磁流体。
β-雷琐酸大环内酯(RALs)是一类结构独特的真菌代谢产物,迄今发现约40个天然RALs,它们基本都含一个1、2、4、6位四取代的苯环,并通过苯环6位连出的长碳链的10 位与1位酯基连接形成苯并14元环大环内酯.尽管已发现的RALs数量不多,但其中不少RALs因其独特的生物活性而备受关注,如具类雌激素作用的微生物毒素zearalenone、抗疟活性突出的aigialomycin D和paecilo
The biosynthetic cationic polyene cyclizations of acyclic precursors squalene and (3S)-2,3-oxidosqualene lead to a vast array of known tricyclic,tetracyclic and pentacyclic natural products.2 In parti
NAD+/NADH辅酶对是生命体内最重要的辅酶之一,它可以通过转移一个质子和两个电子(表观上一个负氢)来转移能量。它的氧化还原机理一直是化学家和生物学家研究的热点[1],但一直存在着众多争议[2]。如果没有具体的热力学和动力学数据以及直接检测到反应活性中间体的信息,我们很难判断氧化还原机理。我们用取代的1,4-二氢吡啶(G-BNAH 和G-PNAH)及其双氘代化合物作为NADH 模型物,详细研究了
本文研究了锦纶6 添加三烯丙基氰脲酸酯(TAC)前后的辐射交联,纯锦纶6 的起始凝胶化剂量为500KGy,添加5%TAC 后降至12KGy;采用XRD、DSC、TG 等方法对锦纶6 交联后的结构、热性能以及防熔滴性能、力学性能等进行了分析。结果表明:在10-200KG 的辐照剂量范围内,随着凝胶含量的增大,锦纶6 的熔滴现象有一定程度的改善;辐照对断裂强度有一个补强的作用,强度先增大后减少,断裂伸
Carbenoid chemistry has become a powerful tool in organic synthesis,diazo compounds are commonly used important precursors of metal carbene,and they have attracted considerable attentions over the pas