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Efficient Synthesis of All-Carbon Quaternary Centers via the Conjugate Addition of Functionalized Monoorganozinc Bromides
Published on: May 26, 2019
Novel one-pot method for chemoselective bromination and sequential Sonogashira coupling
Noriki Kutsumura1, Kentaro Niwa, Takao Saito
1Department of Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan. nkutsu@rs.kagu.tus.ac.jp
Organic Letters
|July 3, 2010
Summary
A new one-pot method efficiently brominates and eliminates allyl alcohol derivatives, enabling subsequent Sonogashira coupling. This process features selective elimination of vicinal dibromoalkanes using DBU, even with adjacent O-functional groups.
Area of Science:
- Organic Chemistry
- Synthetic Chemistry
- Catalysis
Background:
- Allyl alcohol derivatives are versatile synthetic intermediates.
- Efficient functionalization of these compounds is crucial for complex molecule synthesis.
- Existing methods for bromination-elimination and coupling can be multi-step and less efficient.
Purpose of the Study:
- To develop a streamlined, one-pot procedure for the synthesis of functionalized alkynes.
- To investigate a chemoselective bromination-elimination reaction.
- To enable sequential Sonogashira coupling following the initial transformation.
Main Methods:
- A one-pot reaction combining bromination-elimination with Sonogashira coupling.
- Utilizing 1,3-dibromination of allyl alcohol derivatives.
- Employing 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) for chemoselective elimination.
- Palladium-catalyzed Sonogashira coupling with terminal alkynes.
Main Results:
- Successful synthesis of various substituted alkynes in a single pot.
- High chemoselectivity observed in the DBU-promoted elimination of vicinal dibromoalkanes with adjacent O-functional groups.
- The method tolerates a range of functional groups, demonstrating its broad applicability.
- Good yields achieved for the sequential bromination-elimination and Sonogashira coupling.
Conclusions:
- The developed one-pot method offers an efficient and practical route to functionalized alkynes.
- Chemoselective DBU-promoted elimination is a key step, simplifying the synthetic sequence.
- This approach enhances synthetic efficiency for constructing complex organic molecules.
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