1. Microwave-Assisted Organocatalyzed Rearrangement of Propargyl Vinyl Ethers to Salicylaldehyde Derivatives: An Experimental and Theoretical Study.
- Author
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Tejedor, David, Cotos, Leandro, Márquez ‐ Arce, Daniel, Odriozola ‐ Gimeno, Mikel, Torrent ‐ Sucarrat , Miquel, Cossío, Fernando P., and García ‐ Tellado, Fernando
- Subjects
VINYL ethers ,BENZOPHENONES ,PROPARGYLAMINES ,POLYCYCLIC aromatic compounds ,AROMATIZATION - Abstract
The microwave-assisted imidazole-catalyzed transformation of propargyl vinyl ethers (PVEs) into multisubstituted salicylaldehydes is described. The reaction is instrumentally simple, scalable, and tolerates a diverse degree of substitution at the propargylic position of the starting PVE. The generated salicylaldehyde motifs incorporate a broad range of topologies, spanning from simple aromatic monocycles to complex fused polycyclic systems. The reaction is highly regioselective and takes place under symmetry-breaking conditions. The preparative power of this reaction was demonstrated in the first total synthesis of morintrifolin B, a benzophenone metabolite isolated from the small tree Morinda citrifolia L. A DFT study of the reaction was performed with full agreement between calculated values and experimental results. The theoretically calculated values support a domino mechanism comprising a propargyl Claisen rearrangement, a [1,3]-H shift, a [1,7]-H shift (enolization), a 6π electrocyclization, and an aromatization reaction. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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