Abstract
Diene-transmissive hetero-Diels–Alder sequences involving carbonyl dienophiles are reported for the first time. High enantioselectivities are achieved in the reaction of phenylglyoxal with a broad range of dendralene structures, through the optimization of a Pd2+ catalyst system. The initial catalyst-controlled enantioselective oxa-Diels–Alder (ODA) cycloaddition to a [3]dendralene generates a dihydropyran carrying a semicyclic diene. This participates in a subsequent catalyst or substrate-controlled Diels–Alder reaction to generate sp3-rich fused polycyclic systems containing both heterocycles and carbocycles. Computational investigations reveal a concerted asynchronous mechanism. π-Complexation of a diene C=C bond to Pd2+ occurs in both the pre-transition state (TS) complex and in cycloaddition TSs, controlling stereoselectivity. A formal enantioselective [4+2]cycloaddition of a CO2 dienophile is demonstrated.
Original language | English |
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Article number | e202204872 |
Number of pages | 6 |
Journal | Angewandte Chemie - International Edition |
Volume | 61 |
Issue number | 39 |
Early online date | 28 Jul 2022 |
DOIs | |
Publication status | Published - 26 Sept 2022 |
Keywords
- Asymmetric Catalysis
- Cycloadditions
- Dendralenes
- Domino Reactions
- Hydrocarbons