What the study found
The study found that 2-lithiomethylindoles, which are organolithium reagents, can be used as versatile starting points for making many 2-functionalized indoles. The authors report that the approach worked with several kinds of electrophiles and with multiple indole substrates.
Why the authors say this matters
The authors suggest the method is valuable because it opens access to new functionalized indole derivatives, a useful class of compounds in synthesis. They also say that using deep eutectic solvents, mixtures that can support reactions under air- and moisture-tolerant conditions, highlights a greener and operationally simple character.
What the researchers tested
The researchers tested a protocol for generating 2-lithiomethylindoles, using BuLi (n-butyllithium) at room temperature as the most effective condition. They then trapped the organolithium reagents with electrophiles such as Weinreb amides, ketones, alkyl bromides, and epoxides, and applied the method to different 2-methylindoles and 2-benzylindoles.
What worked and what didn't
BuLi at room temperature was reported as the most effective way to form the 2-lithiomethylindole intermediates. The intermediates were efficiently trapped with diverse electrophiles, giving a broad range of C2-functionalized indoles in good yields, and the method was also successful across indoles with different substituents on the benzenoid ring, at C3, and on nitrogen.
What to keep in mind
The abstract does not describe specific failed substrates, low-yield cases, or detailed limitations. It also provides only a brief summary of the subsequent derivatization example, which is the two-step preparation of 2,4-disubstituted carbazoles.
Key points
- 2-lithiomethylindoles were used as intermediates for making 2-functionalized indoles.
- BuLi at room temperature was described as the most effective protocol for forming the organolithium reagents.
- Weinreb amides, ketones, alkyl bromides, and epoxides were all used as trapping agents.
- The method worked with differently substituted 2-methylindoles and with 2-benzylindoles.
- Deep eutectic solvents allowed the reactions to proceed under air- and moisture-tolerant conditions.
Disclosure
- Research title:
- 2-Lithiomethylindoles enable broad 2-functionalized indole synthesis
- Authors:
- Sara Gómez‐Gil, Marta Solas, Samuel Suárez‐Pantiga, Roberto Sanz
- Institutions:
- Universidad de Burgos, Universidad de Burgos, Universidad de Burgos, Universidad de Burgos
- Publication date:
- 2026-02-23
- OpenAlex record:
- View
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