Related Experiment Video

Updated: Jun 1, 2026

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes
09:54

Chemoselective Preparation of 1-Iodoalkynes, 1,2-Diiodoalkenes, and 1,1,2-Triiodoalkenes Based on the Oxidative Iodination of Terminal Alkynes

Published on: September 12, 2018

(4'-All-yloxy-2,2':6',2''-terpyridine)(dibenzoyl-methanido)dinitratoerbium(III) acetonitrile solvate

Qunbo Mei, Bihai Tong

    Acta Crystallographica. Section E, Structure Reports Online
    |May 18, 2011
    PubMed

    More Related Videos

    Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions04:38

    Preparation of Contiguous Bisaziridines for Regioselective Ring-Opening Reactions

    Published on: July 28, 2022

    Related Concept Videos

    Acidity of 1-Alkynes02:42

    Acidity of 1-Alkynes


    The acidic strength of hydrocarbons follows the order: Alkynes > Alkenes > Alkanes. The strength of an acid is commonly expressed in units of pKa — the lower the pKa, the stronger the acid. Among the hydrocarbons, terminal alkynes have lower pKa values and are, therefore, more acidic. For example, the pKa values for ethane, ethene, and acetylene are 51, 44, and 25, respectively, as shown here.
    Nomenclature of Alkynes02:39

    Nomenclature of Alkynes

    Alkynes are unsaturated hydrocarbons characterized by the presence of carbon-carbon triple bonds and have a general formula CnH2n-2. The nomenclature of alkynes follows a set of rules similar to alkanes and alkenes; however, alkynes bear the suffix "-yne" instead of "-ane" or "-ene." There are two approaches to naming alkynes:
    Solvents01:12

    Solvents

    A solvent is a substance, most often a liquid, that can dissolve other substances. Here, the substance being dissolved is called a solute. When a solvent and a solute combine, they form a solution - a homogenous mixture of both the solvent and the solute. Water is a universal biological solvent. Its polar structure allows it to dissolve many other polar compounds. The ability of water to dissolve is governed by a balance between water molecules binding to each other and binding to the solute.
    A...
    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.
    Hydroboration-Oxidation of Alkenes03:08

    Hydroboration-Oxidation of Alkenes

    In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
    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...