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Reactions of Donor–Acceptor Cyclopropanes with Naphthoquinones: Redox and Lewis Acid Catalysis Working in Concert
Author(s) -
Lücht Alexander,
Patalag Lukas J.,
Augustin André U.,
Jones Peter G.,
Werz Daniel B.
Publication year - 2017
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201703732
Subject(s) - umpolung , chemistry , nucleophile , lewis acids and bases , electrophile , catalysis , ring (chemistry) , photochemistry , medicinal chemistry , lewis acid catalysis , redox , organic chemistry
Reactions of 2‐arylcyclopropane dicarboxylates with naphthoquinones are reported. The key feature was the use of catalytic amounts of SnCl 2 , which acts as both an electron donor and a Lewis acid. By an in situ umpolung of naphthoquinone the formerly electrophilic species is converted into a nucleophile that is able to trigger the ring‐opening of the three‐membered ring with formation of a new C−C bond. Treatment of these products with base under oxidative conditions resulted—through loss of methyl formate—in cyclopentannulated products with fully conjugated π systems exhibiting intensive absorptions in the visible range.