Titanium-Catalyzed Intermolecular Hydrothiomethylation of Alkenes
Hermann Thye1, Felix Fornfeist1, Levi L Schlüschen1
1Institut für Chemie, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany.
Chemistry (Weinheim an Der Bergstrasse, Germany)
|November 28, 2025
Summary
A new titanium catalyst enables hydrothiomethylation of alkenes via C-H activation of methyl sulfides. This efficient reaction yields branched products with high selectivity, offering a novel synthetic route.
Area of Science:
- Organometallic Chemistry
- Catalysis
- Organic Synthesis
Background:
- Methyl sulfides are versatile building blocks in organic synthesis.
- Hydrothiomethylation reactions are valuable for introducing sulfur-containing functional groups.
- Developing efficient and selective catalytic methods for C-H functionalization is a key area in modern chemistry.
Purpose of the Study:
- To screen catalysts for α-alkylation of methyl sulfides with unsaturated substrates.
- To develop a novel titanium-catalyzed hydrothiomethylation reaction.
- To investigate the scope and selectivity of the new reaction.
Main Methods:
- Catalyst screening using a 42-well aluminum reactor block.
- In situ preparation of the titanium catalyst from Ti(CH2SiMe3)4, a formamidinato ligand precursor, and [Ph3C][B(C6F5)4].
- Reactions with various alkenes and dimethyl sulfide.
Main Results:
- Discovery of a new titanium-catalyzed hydrothiomethylation reaction involving C-H activation.
- Optimal catalyst system identified for high yields and regioselectivity.
- Exclusive formation of branched hydrothiomethylation products with monosubstituted 1-alkenes (23 examples).
- Selective synthesis of mono- or dihydrothiomethylation products with dimethyl sulfide.
Conclusions:
- The developed titanium catalyst system is highly effective for hydrothiomethylation of alkenes.
- The reaction proceeds via C-H activation at the α-carbon of methyl sulfides.
- The method offers excellent control over regioselectivity, producing valuable branched products.
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