Related Experiment Video

Updated: Jun 4, 2026

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes
12:27

Synthesis of Hypervalent Iodonium Alkynyl Triflates for the Application of Generating Cyanocarbenes

Published on: September 8, 2013

Cleavage at met-x bonds by cyanogen bromide

Richard J Simpson

    CSH Protocols
    |March 2, 2011
    PubMed
    Summary

    Cyanogen bromide selectively cleaves proteins at methionine residues, producing large peptide fragments. This protocol details a reliable method using excess cyanogen bromide under mild acidic conditions for efficient protein fragmentation.

    More Related Videos

    Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides07:50

    Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides

    Published on: May 26, 2019

    Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene09:45

    Accessing Valuable Ligand Supports for Transition Metals: A Modified, Intermediate Scale Preparation of 1,2,3,4,5-Pentamethylcyclopentadiene

    Published on: March 20, 2017

    Related Concept Videos

    Aldehydes and Ketones with HCN: Cyanohydrin Formation Mechanism01:10

    Aldehydes and Ketones with HCN: Cyanohydrin Formation Mechanism

    Cyanohydrins are formed when cyanide nucleophiles and carbonyl compounds like aldehydes and ketones react. A strong base, the cyanide ion, catalyzes cyanohydrin formation. The ions are generated from HCN under aqueous conditions. Once the cyanide ions are generated, the first step involves the nucleophilic attack of the cyanide ions on the electrophilic carbonyl carbon. This attack shifts the π electrons from the C=O to the oxygen atom forming the alkoxide ion intermediate. The alkoxide anion...
    Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview01:32

    Aldehydes and Ketones with HCN: Cyanohydrin Formation Overview

    Cyanohydrins are compounds that contain –CN and –OH groups on the same carbon atom. They are formed by the nucleophilic addition of the cyanide ions to the carbonyl group. Cyanide ions are highly basic and nucleophilic and can be generated from HCN under aqueous conditions. However, since HCN is a weak acid, the number of cyanide ions generated is very small. Hence, a small amount of base or KCN/NaCN is added to HCN to increase the concentration of the cyanide ions in the reaction mixture.
    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.
    Alkynes to Carboxylic Acids: Oxidative Cleavage02:01

    Alkynes to Carboxylic Acids: Oxidative Cleavage

    Alkynes undergo oxidative cleavage in the presence of oxidizing reagents like potassium permanganate and ozone. The triple bond — one σ bond and two π bonds — is completely cleaved, and the alkyne is oxidized to carboxylic acids. When warm and basic aqueous potassium permanganate is used as an oxidizing agent, alkynes are first converted to carboxylate salts via an unstable α-diketone intermediate. Further, a mild acid treatment protonates the carboxylate anions generating free carboxylic acid...
    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.
    Radical Formation: Homolysis00:54

    Radical Formation: Homolysis

    A bond is formed between two atoms by sharing two electrons. When this bond is broken by supplying sufficient energy, either two electrons can be taken up by one atom forming ions by the cleavage called heterolysis, or the two electrons are shared by two atoms, with one each creating radicals by the cleavage called homolysis.