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Triarylborane-Promoted Cyano-Mukaiyama Aldol Reaction Involving a 1,5-Metalate Shift.
Hongliang Zhao1, Meijun Xiong2, Qing Han3
1High & New Technology Research Center, Henan Academy of Sciences, Zhengzhou 450002, P. R. China.
Organic Letters
|June 8, 2026
Summary
A novel cascade reaction enables efficient synthesis of 3-aminoindenonones using cyano-allenol ethers and triphenylboranes. This method offers broad substrate scope and functional group tolerance under mild conditions.
Area of Science:
- Organic Chemistry
- Synthetic Chemistry
Background:
- Developing efficient synthetic routes for complex organic molecules is crucial.
- 3-Aminoindenonones are valuable structural motifs in medicinal chemistry.
Purpose of the Study:
- To develop an efficient protocol for synthesizing functionalized 3-aminoindenonones.
- To explore a novel cascade reaction involving cyano-allenol ethers and triphenylboranes.
Main Methods:
- A cascade reaction involving *in situ* generated cyano-allenol ethers.
- Activation and coordination roles of triphenylboranes (BAr3) as Lewis acid and coordination bridge.
- Mukaiyama aldol addition followed by a 1,5-metalate shift.
Main Results:
- Efficient synthesis of functionalized 3-aminoindenonones achieved under mild conditions.
- The developed method demonstrates a broad substrate scope and excellent functional group tolerance.
- Triphenylboranes were found to play a dual role in activating the cyano group and facilitating the reaction cascade.
Conclusions:
- A new, efficient, and versatile method for synthesizing 3-aminoindenonones has been established.
- The dual role of BAr3 in the reaction mechanism is highlighted.
- This protocol offers a valuable tool for organic synthesis.
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