1,3-偶极环加成反应因此也分为三类:一类是由1,3-偶极体出HOMO,称为HOMO控制的反应;一类是由1,3-偶极体出LUMO,称为LUMO控制的反应;还有一类就是两种情况都存在,称为(HOMO-LUMO)控制的反应。 1,3-偶极子(1,3-dipole)是三原子形成的4π电子化学...
1,3-Dipolar cycloaddition of 6,7-dialkoxy-3,4-dihydroisoquinolinium salts to dipolarophiles of azomethin- and alkene type have been investigated. The regioselectivity of the reactions rationalized on the basis of the perturbation theory, using CNDO/2 and CNDO/S approximations. Good agreement ...
相关工作以“Arenes participate in 1,3-dipolar cycloaddition with in situ-generated diazoalkenes”为题发表在Nat. Chem.上(DOI: 10.1038/s41557-023-01188-z)。 1,3-偶极环加成反应已被研究了超过一个世纪,该反应在含有五元杂环化合物的合成中被广泛应用。在经典的1,3-偶极环加成反应中,烯烃和炔烃作为亲偶...
近日,清华大学李艳梅团队报道了一种光触发的四氮唑类杂环化合物与 Dha 残基之间的 1,3-偶极环加成反应,该反应无需催化剂,仅通过施加短时间的光照即可开启反应,从而能够实现对各种多肽及蛋白底物的快速高效化学修饰。 该项工作以 “Light...
Cyanameisensaure-ethylester lagert das Azomethin-imin 1 zum Δ3-1,2,4-Triazolin-Derivat an.1,3-Dipolar Cycloadditions, 81. Additions of C,C,Nα-Triaryl-Nβ-cyano-azomethine Imines to Dipolarophiles with CN Multiple BondsThe azomethine imines of the title add at room temperature to the...
1,3-偶极环加成反应（1,3-dipolar cycloaddition）是发生在1,3-偶极体和烯烃、炔烃或相应衍生物之间的环加成反应，产物是一个五元杂环化合物。烯烃类化合物在反应中称亲偶极体。德国化学家RolfHuisgen首先广泛应用此类反应制取五元杂环化合物，因此它也称为Huisgen反应。以前曾认为1,3-偶极环加成反应是经过一个双...
The influences of the frontier molecular orbitals and optimized geometry of the precursor on the reaction rates and endo/exo selectivity are discussed,and a reasonable explanation about the steroselectivity of 1,3-dipolar cycloaddition reaction in the presence of copper-(Ⅱ)-or. 用理论计算方法研究...
A 1,3-dipolar cycloaddition reaction is defined as a reaction involving a dipolarophile and 1,3-dipolar compounds containing one or more heteroatoms which can be described as having at least one mesomeric state structure that represents a charged dipole. ...
通过理论计算,作者提出了反应途径并揭示了一系列精细协调的断键和成键过程。相关工作以“Arenes participate in 1,3-dipolar cycloaddition with in situ-generated diazoalkenes”为题发表在Nat. Chem.上(DOI: 10.1038/s41557-023-01188-z)。 1,3-偶极环加成反应已被研究了超过一个世纪,该反应在含有五元杂环化合...
1,3-Dipolar cycloadditions of diphenyldiazomethane to thioketones afford 2,5-dihydro-1,3,4-thiadiazoles 8, which rapidly lose N2. The liberated thiocarbonyl ylides 10 furnish thiiranes 9 by electrocyclic ring closure. The rate constants, measured by spectrophotometry (DMF, 40掳C) for 16 ...