NHC-Catalyzed Asymmetric Formal 4 + 2 Annulation To Construct Spirocyclohexane Pyrazolone Skeletons.

08:00 EDT 12th September 2019 | BioPortfolio

Summary of "NHC-Catalyzed Asymmetric Formal 4 + 2 Annulation To Construct Spirocyclohexane Pyrazolone Skeletons."

A chiral N-heterocyclic carbene (NHC)-catalyzed [4 + 2] annulation of γ-chloroenals and α-arylidene pyrazolinones was developed in the absence of expensive oxidants. The reaction proceeds smoothly via a vinyl enolate intermediate to afford spirocyclohexane pyrazolones in moderate to good yield (up to 86%) with high diastereoselectivities (up to 15:1 ) and excellent enantioselectivities (up to >99% ).


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Name: Organic letters
ISSN: 1523-7052


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