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Efficient Synthesis of N-Carbamoylpropargylamines from α-Amido Sulfones Using Dimethylalkynylaluminum Reagents

Ji-Hoon Lee, Sang-Hyeup Lee*

*Department of Chemistry, Daegu Catholic University, Hayang-Ro 13-13, Gyeongsan, Gyeongbuk 38430, Korea, Email: leeshhcu.ac.kr

J.-H. Lee, S.-H. Lee, Synthesis, 2022, 54, 2233-2241.

DOI: 10.1055/s-0041-1737763


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Abstract

The addition of dimethylalkynylaluminum reagents derived from terminal alkynes and trimethylaluminum to various N-activated α-amido sulfones provides the corresponding propargylamines in good yields. The use of stable, N-activated α-amido sulfone avoids the preparation and isolation of relatively unstable N-activated imines.

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Details

The document details a study on the efficient synthesis of N-carbamoylpropargylamines from α-amido sulfones using dimethylalkynylaluminum reagents. This method avoids the preparation and isolation of unstable N-activated imines by generating them in situ from stable α-amido sulfones. The optimized protocol allows for the production of alkynylamines in moderate to excellent yields (51-98%) under mild conditions. The study highlights the importance of propargylamines in biologically active compounds and their use as building blocks in chemical transformations. Traditional methods using Grignard or organolithium reagents have limitations, such as low functional group tolerance and demanding conditions. The new method using dimethylalkynylaluminum reagents offers better functional group tolerance and avoids the use of expensive catalysts and long reaction times associated with transition-metal-mediated methods. The scope of the protocol was tested with various N-activated α-amido sulfones and terminal alkynes, yielding good to high results. The study concludes that this method is versatile and efficient for synthesizing primary alkynylamines in protected forms, making it valuable for pharmaceutical applications.


Key Words

ethylalkynylaluminum reagents, nucleophilic addition, propargylamines, N-activated α-amido sulfones, alkynylamines


ID: J66-Y2022