Related Experiment Video

Updated: May 18, 2026

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
06:46

Facile Preparation of (2Z,4E)-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate

Published on: June 21, 2017

(1E,2E)-1,2-Bis(2,3-dihydro-1H-inden-1-yl-idene)hydrazine

Wolfgang Imhof, Joachim Wunderle

    Acta Crystallographica. Section E, Structure Reports Online
    |September 13, 2012
    PubMed

    More Related Videos

    A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones07:30

    A Direct, Regioselective and Atom-Economical Synthesis of 3-Aroyl-N-hydroxy-5-nitroindoles by Cycloaddition of 4-Nitronitrosobenzene with Alkynones

    Published on: January 21, 2020

    Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles11:45

    Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles

    Published on: August 22, 2018

    Related Concept Videos

    Structure of Conjugated Dienes01:16

    Structure of Conjugated Dienes

    Introduction
    Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
    Diazonium Group Substitution: –OH and –H01:19

    Diazonium Group Substitution: –OH and –H

    Nitrous acid, a weak acid, is prepared in situ via the reaction of sodium nitrite with a strong acid under cold conditions. This nitrous acid prepared in situ reacts with primary arylamines to form arenediazonium salts. Such reactions are known as diazotization reactions. As shown in Figure 1, the formation of arenediazonium salts begins with the decomposition of nitrous acid in an acidic solution to give nitrosonium ions.
    Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene01:14

    Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene

    Electrophilic addition of halogens to alkenes proceeds via a cyclic halonium ion to form a 1,2-dihalide or a vicinal dihalide.
    E1 Reaction: Stereochemistry and Regiochemistry02:43

    E1 Reaction: Stereochemistry and Regiochemistry

    One of the critical aspects of the E1 reaction mechanism, as also observed in E2, is the regiochemistry, with multiple regioisomers obtained as products. In the example discussed, the presence of water as a weak base favors elimination over substitution to generate two alkenes. Given that alkenes’ stability increases with the number of alkyl groups across the double bond, typically, E1 reactions lead to the Zaitsev product, for this is more substituted and stable than the Hofmann product.
    [4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction01:16

    [4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction

    The Diels–Alder reaction is an example of a thermal pericyclic reaction between a conjugated diene and an alkene or alkyne, commonly referred to as a dienophile. The reaction involves a concerted movement of six π electrons, four from the diene and two from the dienophile, forming an unsaturated six-membered ring. As a result, these reactions are classified as [4+2] cycloadditions.
    Diels–Alder Reaction: Characteristics of Dienes01:29

    Diels–Alder Reaction: Characteristics of Dienes

    The Diels–Alder reaction brings together a diene and a dienophile to form a six-membered ring. Both components have unique characteristics that influence the rate of the reaction.
    Characteristics of the diene
    Conformation
    The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is more stable, the...