Route to Benzo- and Pyrido-Fused 1,2,4-Triazinyl Radicals via <i>N</i>′-(Het)aryl-<i>N</i>′-[2-nitro(het)aryl]hydrazides
作者:Andrey A. Berezin、Georgia Zissimou、Christos P. Constantinides、Yassine Beldjoudi、Jeremy M. Rawson、Panayiotis A. Koutentis
DOI:10.1021/jo402481t
日期:2014.1.3
involves the N′-(2-nitroarylation) of easily prepared N′-(het)arylhydrazides via nucleophilic aromatic substitution of 1-halo-2-nitroarenes, which in most cases gives N′-(het)aryl-N′-[2-nitro(het)aryl]hydrazides in good yields. Mild reduction of the nitro group followed by an acid-mediated cyclodehydration gives the fused triazines, which upon alkali treatment afford the desired radicals. Fifteen examples
Intramolecular Diels–Alder and [3+2] Cycloaddition Reactions in the One-Pot Synthesis of Epoxypyrrolo[3,4-g]indazoles
作者:Abdolali Alizadeh、Kaveh Amir Ashjaee Asalemi、Mohammadreza Halvagar
DOI:10.1055/s-0037-1612426
日期:2019.8
intramolecular Diels–Alder (IMDA) reaction. A one-pot approach for the synthesis of epoxypyrrolo[3,4-g]indazoles is presented. The first step was initiated by a three-componentreaction of an isocyanide, a dialkyl acetylenedicarboxylate, and 2-furancarboxylic acid, and led to 1,3-dioxoepoxyisoindole, followed by the addition of hydrazonoyl chloride through a [3+2]-cycloaddition reaction in the second
抽象的 提出了一种一锅法合成环氧吡咯并[3,4- g ]吲唑的方法。第一步是由异氰酸酯,乙炔二羧酸二烷基酯和2-呋喃羧酸的三组分反应引发的,并生成1,3-二氧代环氧异吲哚,然后通过[3 + 2]-环加成反应加入酰氯。第二步反应。形成最终化合物的关键步骤涉及通过分子内Diels–Alder(IMDA)反应的双环化策略。 提出了一种一锅法合成环氧吡咯并[3,4- g ]吲唑的方法。第一步是由异氰酸酯,乙炔二羧酸二烷基酯和2-呋喃羧酸的三组分反应引发的,并生成1,3-二氧代环氧异吲哚,然后通过[3 + 2]-环加成反应加入酰氯。第二步反应。形成最终化合物的关键步骤涉及通过分子内Diels–Alder(IMDA)反应的双环化策略。
A formal [3+2] cycloaddition reaction of <i>N</i>-methylimidazole as a masked hydrogen cyanide: access to 1,3-disubstitued-1<i>H</i>-1,2,4-triazoles
作者:Issa Yavari、Omid Khaledian
DOI:10.1039/d0cc01065k
日期:——
N-Methylimidazole (NMI) can act as a masked HCN in the synthesis of 1,3-disubstitued-1H-1,2,4-triazoles via a formal cycloaddition reaction of hydrazonoyl chloride with NMI. The product was proved to be formed via an initial nucleophilic substitution of hydrazonoyl chloride with NMI following cyclization and two sequential C–N bond cleavages.
N-甲基咪唑(NMI)可通过1,酰氯与NMI的正式环加成反应在合成1,3-二取代-1 H -1,2,4-三唑中充当掩蔽的HCN 。事实证明,该产物是通过环化反应和两次连续的C–N键裂解后,用NMI进行酰肼基氯的初始亲核取代而形成的。
Synthesis of Spirobidihydropyrazole through Double 1,3-Dipolar Cycloaddition of Nitrilimines with Allenoates
The double 1,3-dipolar cycloaddition of allenoates with nitrilimines has been achieved under mild reaction conditions, affording a variety of spirobidihydropyrazoles in moderate to excellent yields with excellent diastereoselectivities. The reaction diastereoselectively constructs double dihydropyrazole moieties and two chiral centers including a spiro carbon center.
A [4 + 3] Annulation Reaction of aza-<i>o</i>-Quinone Methides with Arylcarbohydrazonoyl Chlorides for Synthesis of 2,3-Dihydro-1<i>H</i>-benzo[<i>e</i>][1,2,4]triazepines
An unprecedented [4 + 3] annulation reaction of aza-ortho-quinone methides with arylcarbohydrazonoyl chlorides has been achieved under mild conditions. The annulation underwent a sequential conjugate addition/intramolecular annulation/rearrangement, providing a useful method for the synthesis of biologically interesting 2,3-dihydro-1H-benzo[e][1,2,4]triazepine.
在温和的条件下,已完成了氮杂-邻苯醌甲基化物与芳基羰基肼基甲酰氯的前所未有的[4 + 3]环化反应。进行连续的共轭加成/分子内的成环/重排,为生物上有趣的2,3-二氢-1 H-苯并[ e ] [1,2,4]三氮杂卓合成提供了有用的方法。