Title : Captodative Enamides: from Controlled Syntheses to Original Heterocycles
Abstract:
Enaminals are valuables building blocks in organic synthesis as they open the door to a wide range of more complex structures such as polyfunctionalized heterocycles or act as precursors of unconventional ? and ???? amino-acids for instance. Noteworthy, both regioisomers (? or ???? enaminals) are appealing as they allow access to different molecular edifices. If ????-enaminals, being valuable push-pull building blocks, have been well studied in the past, ?-enaminals, having this time a captodative character, have been much less investigated and remain really complex to obtain, especially if you target tri- or tetra-substituted scaffolds with complete control of the regio- and stereo-chemistry. During the past few years we have developed diverse methodologies based on carbonylation and silylation reactions on ynamides to obtain versatile enaminal derivatives. Notably these methodologies are highly stereo- and regio- controlled. Among the reactions that will be introduced, we will present the first examples of regiodivergent hydroformylation of alkynes which are totally controlled by the nature of the ligand used. In addition we will also introduce the controlled synthesis of various silylated enaminal-derivatives as well as their post-functionalization leading to a wide scope of original and valuable building blocks. Nicely, these new compounds open the door to rapid and efficient syntheses of original heterocycles.
Audience take-away:
- How to control efficiently, thanks to the catalytic conditions, the difunctionalization of ynamides.
- How to control the dual character (electrophilic & nucleophilic) of captodative enaminals.
- The potential of captodative enamines as building blocks in organic synthesis
