质子酸催化不对称Diels–Alder Reactions，螺四氢咔唑-3,3-吲哚酮框架的立体选择性
Brønsted Acid Catalyzed Asymmetric Diels–Alder Reactions: Stereoselective Construction of Spiro[tetrahydrocarbazole-3,3′-oxindole] Framework
Yang Wang , Man-Su Tu , Lei Yin , Meng Sun , and Feng Shi *
Jiangsu Key Laboratory of Green Synthetic Chemistry for Functional Materials, School of Chemistry and Chemical Engineering, Jiangsu Normal University, Xuzhou, 221116, China
J. Org. Chem
The chiral phosphoric acid catalyzed asymmetric Diels–Alder reactions of 2-vinylindoles with methyleneindolinones have been established, which efficiently construct the spiro[tetrahydrocarbazole-3,3′-oxindole] architecture with one quaternary and three contiguous stereogenic centers in high yields (up to 99%) and
excellent stereoselectivities (up to >95:5 dr, 97% ee). This reaction not only provides an efficient strategy to access enantioenriched spiro[tetrahydrocarbazole-3,3′-oxindoles] based on hydrogen-bonding activation mode but also supplies successful examples of catalytic asymmetric Diels–Alder reactions for constructing complex spiro-frameworks with optical purity.
