A highly enantioselective cascade reaction for the generation of five quaternary stereocenters in one-pot operation is reported for the first time in the history of organic synthesis. Cinchona-alkaloid derived hydrogen-bonding catalyst furnished structurally complex cascade products from simple substrates in excellent yields and stereoselectivities.
View Article and Find Full Text PDFA novel, base-catalyzed and highly diastereoselective direct Michael addition-isomerization sequence is presented for the efficient synthesis of Rauhut-Currier-type adducts. An unexpected α-addition of γ-butyrolactam onto the 3-acyl coumarin derivatives was observed rather than the γ-addition, which is more common. The adducts could further undergo hydrolysis/decarboxylation to generate the products which are equivalent to those obtained by α-addition of γ-butyrolactam onto the corresponding chalcones.
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