Decarboxylative [4+2] Cycloaddition by Synergistic Palladium and Organocatalysis |
| |
Authors: | Lars A Leth Dr Florian Glaus Dr Marta Meazza Dr Liang Fu Mathias K Thøgersen Emma A Bitsch Prof?Dr Karl Anker Jørgensen |
| |
Institution: | Department of Chemistry, Aarhus University, Aarhus C, Denmark |
| |
Abstract: | A novel reaction based on synergistic catalysis, combining palladium‐ and organocatalysis has been developed. The palladium catalyst activates vinyl benzoxazinanones via a decarboxylation to undergo a 4+2] cycloaddition with iminium‐ion activated α,β‐unsaturated aldehydes. The reaction is demonstrated to proceed for a number of combinations of vinyl benzoxazinanones reacting with α,β‐unsaturated aldehydes, providing highly substituted vinyl tetrahydroquinolines in good to high yields, and excellent enantio‐ and diastereoselectivities (>98 % ee and >20:1 d.r.). The palladium catalyst used in the synergistic catalysis can be re‐used in a one‐pot sequential coupling reaction with an aromatic boronic acid forming the coupling product in 95 % yield, >20:1 d.r. and 99 % ee. |
| |
Keywords: | asymmetric catalysis cycloaddition decarboxylation heterocycles synergistic catalysis |
|
|