American Chemical Society
jo9b03076_si_001.pdf (4.33 MB)

Organocatalytic Asymmetric Hetero-Diels–Alder Reaction of in Situ Generated Dienes: Access to α,β-Unsaturated δ‑Lactones Featuring CF3‑Substituted Quaternary Stereocenter

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journal contribution
posted on 2020-01-28, 18:06 authored by Harshit Joshi, Ankit Yadav, Arko Das, Vinod K. Singh
Chiral bifunctional urea-catalyzed asymmetric direct hetero-DielsAlder reaction between alkylidene azlactone-derived dienes and trifluoromethyl aryl ketones is reported for the first time. The direct hetero-DielsAlder reaction followed by ring opening results in densely functionalized α,β-unsaturated δ-lactones featuring a CF3-substituted quaternary stereocenter in high yields with excellent enantioselectivities. The method is compatible over a range of substrates. Moreover, the reaction is scaled up and the α,β-unsaturated δ-lactones were converted to amino acid derivatives decorated with trifluoromethylated carbinol functionality.