Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Conversion of Alcohols to Alkyl Halides02:48

Conversion of Alcohols to Alkyl Halides

7.7K
This lesson delves into the conversion of alcohols to corresponding alkyl halides and the mechanism of action for different reagents. Typically, the hydroxyl group is first protonated to convert it to a stable leaving group. Consequently, based on the starting alcohol, the mechanism undergoes either of the nucleophilic substitution routes, SN1 or SN2. Tertiary alkyl halides are made using the two-step SN1 mechanism that occurs via a carbocation intermediate, which is stabilized by...
7.7K
Radical Substitution: Halogenation of Alkanes and Alkyl Substituents01:27

Radical Substitution: Halogenation of Alkanes and Alkyl Substituents

9.2K
In the presence of heat or light, alkanes react with molecular halogens to form alkyl halides by a substitution reaction called radical halogenation. This reaction has three steps: initiation, propagation, and termination, as seen in the radical chlorination of methane to produce methyl chloride.
In the initiation step of the reaction, the chlorine molecule undergoes homolytic cleavage in the presence of light or heat, forming two highly reactive chlorine radicals. Propagation occurs in two...
9.2K
Alkyl Halides02:45

Alkyl Halides

18.6K
Structural Properties
Alkyl halides are halogen-substituted alkanes wherein one or more hydrogen atoms of an alkane is replaced by a halogen atom such as fluorine, chlorine, bromine, or iodine. The carbon atom in an alkyl halide is bonded to the halogen atom, which is sp3-hybridized and exhibits a tetrahedral shape.
Unlike alkyl halides, compounds in which a halogen atom is bonded to an sp2 -hybridized carbon atom of a carbon-carbon double bond (C=C) are called vinyl halides. Whereas aryl...
18.6K
Electrophilic Addition to Alkynes: Hydrohalogenation02:35

Electrophilic Addition to Alkynes: Hydrohalogenation

10.6K
Electrophilic addition of hydrogen halides, HX (X = Cl, Br or I) to alkenes forms alkyl halides as per Markovnikov's rule, where the hydrogen gets added to the less substituted carbon of the double bond. Hydrohalogenation of alkynes takes place in a similar manner, with the first addition of HX forming a vinyl halide and the second giving a geminal dihalide.
10.6K
Preparation and Reactions of Sulfides02:26

Preparation and Reactions of Sulfides

5.3K
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.
5.3K
SN2 Reaction: Transition State02:26

SN2 Reaction: Transition State

11.0K
An SN2 reaction of an alkyl halide is a single-step process in which bond formation between the nucleophile and the substrate and bond breaking between the substrate and the halide occurs simultaneously through a transition state without forming an intermediate.
When the nucleophile approaches the electrophilic carbon with its lone pairs, the halide acts as a leaving group and moves away with the electron-pair bonded to the carbon. Dotted partial bonds represent the bonds being formed or broken...
11.0K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Discovery of Novel Plant O-Methyltransferases for Directed Methylation of Flavonoids and Stilbenoids.

Chembiochem : a European journal of chemical biology·2026
Same author

Metal-Dependent Effects and Crowding Robustness of Pseudomonas fluorescens Esterase I.

Chembiochem : a European journal of chemical biology·2026
Same author

High-throughput assays for SAM-dependent methyltransferases: advances, challenges, and future perspectives.

Natural product reports·2026
Same author

Reprogramming of bacterial virulence by lysine acetylation.

Nature communications·2026
Same author

AcuB senses cellular energy charge to coordinate acetyl-CoA synthesis in bacteria.

Nature communications·2026
Same author

Investigation of regioselectivity and thermostability of free and immobilized Pleurotus citrinopileatus lipase.

Applied microbiology and biotechnology·2026

Related Experiment Video

Updated: Nov 8, 2025

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues
12:07

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues

Published on: November 22, 2014

14.2K

From Natural Methylation to Versatile Alkylations Using Halide Methyltransferases.

Qingyun Tang1, Ioannis V Pavlidis2, Christoffel P S Badenhorst1

  • 1Institute of Biochemistry, University of Greifswald, Felix-Hausdorff-Str. 4, 17489, Greifswald, Germany.

Chembiochem : a European Journal of Chemical Biology
|April 23, 2021
PubMed
Summary

Halide methyltransferases (HMTs) create S-adenosyl-l-methionine (SAM) analogues. Protein engineering expands HMTs

Keywords:
SAM analoguealkyl iodidealkylationhalide methyltransferasemethylation

More Related Videos

Targeted DNA Methylation Analysis by Next-generation Sequencing
08:38

Targeted DNA Methylation Analysis by Next-generation Sequencing

Published on: February 24, 2015

37.6K
An Engineered Split-TET2 Enzyme for Chemical-inducible DNA Hydroxymethylation and Epigenetic Remodeling
08:34

An Engineered Split-TET2 Enzyme for Chemical-inducible DNA Hydroxymethylation and Epigenetic Remodeling

Published on: December 18, 2017

6.8K

Related Experiment Videos

Last Updated: Nov 8, 2025

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues
12:07

Sequence-specific Labeling of Nucleic Acids and Proteins with Methyltransferases and Cofactor Analogues

Published on: November 22, 2014

14.2K
Targeted DNA Methylation Analysis by Next-generation Sequencing
08:38

Targeted DNA Methylation Analysis by Next-generation Sequencing

Published on: February 24, 2015

37.6K
An Engineered Split-TET2 Enzyme for Chemical-inducible DNA Hydroxymethylation and Epigenetic Remodeling
08:34

An Engineered Split-TET2 Enzyme for Chemical-inducible DNA Hydroxymethylation and Epigenetic Remodeling

Published on: December 18, 2017

6.8K

Area of Science:

  • Biocatalysis and enzyme engineering
  • Synthetic biology
  • Organic chemistry

Background:

  • Halide methyltransferases (HMTs) catalyze the synthesis of S-adenosyl-l-methionine (SAM) using methyl iodide.
  • Methionine adenosyltransferases (MATs) also synthesize SAM but require chemical synthesis of methionine analogues and have broader substrate scope.
  • Current HMTs have limited substrate scope compared to MATs.

Purpose of the Study:

  • To explore the discovery and engineering of promiscuous HMTs.
  • To develop a versatile toolbox of HMT variants for biocatalytic alkylations.
  • To expand the substrate scope of HMTs beyond methyl iodide.

Main Methods:

  • Characterization of naturally occurring HMTs.
  • Protein engineering of HMTs to create variants with altered substrate specificities.
  • Evaluation of HMT variants for the synthesis of ethyl, propyl, and allyl SAM analogues.

Main Results:

  • Engineered HMT variants can synthesize ethyl, propyl, and allyl analogues of SAM.
  • HMTs offer an alternative to chemical synthesis of methionine analogues.
  • Demonstrated potential for chemo- and regioselective biocatalytic alkylations using engineered HMTs.

Conclusions:

  • Enzyme engineering has successfully expanded the capabilities of HMTs.
  • Promiscuous HMTs provide a powerful platform for biocatalytic alkylations.
  • A toolbox of HMT variants will enable versatile synthetic applications.