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Dearomatization Reactions of N-OMe Ureas
Nazmee Parveen1, Marian N Aziz1, Delphine Gout1
1Department of Chemistry and Biochemistry, University of Texas Arlington, Arlington, Texas 76019, United States.
Organic Letters
|September 25, 2025
Summary
Chemoselective dearomatization of N-methoxy ureas offers a new route to spirocyclic ureas. This method enables the synthesis of complex molecules, including fragments of the marine alkaloid KB343.
Area of Science:
- Organic Chemistry
- Synthetic Chemistry
Background:
- Dearomatization reactions are crucial for creating complex molecular architectures.
- Controlling chemoselectivity in dearomatization remains a synthetic challenge.
Purpose of the Study:
- To develop a method for controlling chemoselectivity in the dearomatization of benzylic ureas.
- To utilize N-methoxy ureas as stabilized nitrenium ion equivalents for dearomatization reactions.
Main Methods:
- Evaluation of N-methoxy ureas as nitrenium ion precursors.
- Treatment of secondary amine-derived substrates with iodosobenzene diacetate.
- Cyclization reactions to form spirocyclic ureas.
Main Results:
- Successful dearomatization and cyclization of benzylic N-methoxy ureas.
- Formation of spirocyclic ureas in modest to excellent yields.
- Demonstration of the scope and limitations of the developed transformation.
Conclusions:
- N-methoxy ureas are effective stabilized nitrenium ion equivalents for dearomatization.
- The developed method provides access to valuable spirocyclic urea scaffolds.
- The dearomatized products can be further functionalized for natural product synthesis, such as fragments of marine alkaloid KB343.
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