Direct Catalytic Asymmetric Vinylogous Conjugate Addition of Unsaturated Butyrolactones to α,β-Unsaturated Thioamides

• Published in: Angewandte Chemie International Edition 2014-05, Vol.53 (21), p.5327-5331
• Main Authors: Yin, Liang, Takada, Hisashi, Lin, Shaoquan, Kumagai, Naoya, Shibasaki, Masakatsu
• Format: Article
• Language: English
• Subjects: 4-Butyrolactone - chemistry; asymmetric catalysis; Catalysis; copper; Copper - chemistry; heterocycles; Lewis Acids - chemistry; Michael addition; Stereoisomerism; synthetic methods; Thioamides - chemistry
• ISSN: 1433-7851; 1521-3773
• DOI: 10.1002/anie.201402332

Soft Lewis acid/Brønsted base cooperative catalysts have enabled direct catalytic asymmetric vinylogous conjugate addition of α,β‐ and β,γ‐unsaturated butyrolactones to α,β‐unsaturated thioamides with perfect atom economy. When using α‐angelica lactone and its derivatives as pronucleophiles, as little as 0.5 mol % catalyst loading was sufficient to complete the reaction necessary to construct consecutive tri‐ and tetrasubstituted stereogenic centers in a highly diastereo‐ and enantioselective fashion. Soft spot: Soft Lewis acid/Brønsted base cooperative catalysts have enabled the title reaction of α,β‐ and β,γ‐unsaturated butyrolactones with perfect atom economy. When using α‐angelica lactone and its derivatives as pronucleophiles, a 0.5 mol % catalyst loading was sufficient to complete the reaction to construct consecutive tri‐ and tetrasubstituted stereogenic centers in a highly diastereo‐ and enantioselective fashion.