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Visible-Light-Driven N-Heterocyclic Carbene Catalyzed γ- and ϵ-Alkylation with Alkyl Radicals
Lei Dai1,2, Zi-Hao Xia1,2, Yuan-Yuan Gao1,2
1Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
Abstract:
The merging of photoredox catalysis and N-heterocyclic carbene (NHC) catalysis for γ- and ϵ-alkylation of enals with alkyl radicals was developed. The alkylation reaction of γ-oxidized enals with alkyl halides worked well for the synthesis γ-multisubstituted-α,β-unsaturated esters, including those with challenging vicinal all-carbon quaternary centers. The synthesis of ϵ-multisubstituted-α,β-γ,δ-diunsaturated esters by an unprecedented NHC-catalyzed ϵ-functionalization was also established.
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