A Cooperative N‐Heterocyclic Carbene/Chiral Phosphate Catalysis System for Allenolate Annulations |
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| Authors: | Dr Anna Lee Prof Karl A Scheidt |
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| Institution: | Department of Chemistry Center for Molecular Innovation and Drug Discovery, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208 (USA) |
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| Abstract: | The highly enantioselective NHC‐catalyzed 3+2] annulation reaction with α,β‐alkynals and α‐ketoesters has been developed. A new mode of cooperative catalysis involving the combination of a chiral Brønsted acid and a C1‐symmetric biaryl saturated‐imidazolium precatalyst was required to generate the desired γ‐crotonolactones in high yields and levels of enantioselectivity. |
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| Keywords: | annulation asymmetric synthesis cooperative catalysis N‐heterocyclic carbene synthetic methods |
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