Catalytic,Cascade Ring‐Opening Benzannulations of 2,3‐Dihydrofuran O,O‐ and N,O‐Acetals |
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| Authors: | Joel Aponte‐Guzmán Dr Lien H Phun Marchello A Cavitt J Evans Taylor Jr Jack C Davy Prof Dr Stefan France |
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| Affiliation: | 1. School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia, USA;2. Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia, USA |
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| Abstract: | An Al(OTf)3‐catalyzed intramolecular cascade ring‐opening benzannulation of 2,3‐dihydrofuran O,O‐ and N,O‐acetals is described. The cascade sequence involves the dihydrofuran ring‐opening by acetal hydrolysis, an intramolecular Prins‐type cyclization, and aromatization to generate an array of benzo‐fused (hetero)aromatic systems in up to 95 % yield. This method represents the first example of dihydrofuran acetal usage in benzannulation reactions. The approach provides excellent regiocontrol based on the choice of alkenes used to form the requisite dihydrofuran acetals. |
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| Keywords: | benzannulation domino reactions fused-ring systems heterocycles ring-opening cyclizations |
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