Related Experiment Video

Updated: May 20, 2026

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
07:12

Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions

Published on: July 17, 2020

(Z)-3-(4-Bromo-phen-yl)-2-[(2-phenyl-cyclo-hex-2-en-1-yl)imino]-1,3-thia-zol-idin-4-one

Chin Wei Ooi, Hoong-Kun Fun, Ching Kheng Quah

    Acta Crystallographica. Section E, Structure Reports Online
    |July 19, 2012
    PubMed

    More Related Videos

    Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines10:42

    Preparation of N-(2-alkoxyvinyl)sulfonamides from N-tosyl-1,2,3-triazoles and Subsequent Conversion to Substituted Phthalans and Phenethylamines

    Published on: January 3, 2018

    Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts09:58

    Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts

    Published on: February 24, 2015

    Related Concept Videos

    Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene01:13

    Electrophilic Aromatic Substitution: Fluorination and Iodination of Benzene

    Bromination and chlorination of aromatic rings by electrophilic aromatic substitution reactions are easily achieved, but fluorination and iodination are difficult to achieve. Fluorine is so reactive that its reaction with benzene is difficult to control, resulting in poor yields of monofluoroaromatic products. To address this, Selectfluor reagent is used as a fluorine source in which a fluorine atom is bonded to a positively charged nitrogen.
    Halogenation of Alkenes02:46

    Halogenation of Alkenes

    Halogenation is the addition of chlorine or bromine across the double bond in an alkene to yield a vicinal dihalide. The reaction occurs in the presence of inert and non-nucleophilic solvents, such as methylene chloride, chloroform, or carbon tetrachloride.
    Consider the bromination of cyclopentene. Molecular bromine is polarized in the proximity of the π electrons of cyclopentene. An electrophilic bromine atom adds across the double bond, forming a cyclic bromonium ion intermediate.
    Reactions at the Benzylic Position: Halogenation01:11

    Reactions at the Benzylic Position: Halogenation

    Benzylic halogenation takes place under conditions that favor radical reactions such as heat, light, or a free radical initiator like peroxide.
    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.
    Preparation and Reactions of Sulfides02:26

    Preparation and Reactions of Sulfides

    Sulfides are the sulfur analog of ethers, just as thiols are the sulfur analog of alcohol. Like ethers, sulfides also consist of two hydrocarbon groups bonded to the central sulfur atom. Depending upon the type of groups present, sulfides can be symmetrical or asymmetrical. Symmetrical sulfides can be prepared via an SN2 reaction between 2 equivalents of an alkyl halide and one equivalent of sodium sulfide.
    ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH301:11

    ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3

    All ortho–para directors, excluding halogens, are activating groups. These groups donate electrons to the ring, making the ring carbons electron-rich. Consequently, the reactivity of the aromatic ring towards electrophilic substitution increases. For instance, the nitration of anisole is about 10,000 times faster than the nitration of benzene. The electron-donating effect of the methoxy group in anisole activates the ortho and para positions on the ring and stabilizes the corresponding...