64261-57-0Relevant articles and documents
C5-Disubstituted Meldrum's Acid Derivatives as Platform for the Organocatalytic Synthesis of C3-Alkylated Dihydrocoumarins
Martzel, Thomas,Annibaletto, Julien,Levacher, Vincent,Brière, Jean-Fran?ois,Oudeyer, Sylvain
, p. 995 - 1000 (2019)
C5-disubstituted Meldrum's acid precursors were shown to be a useful platform for the synthesis of an array of 3-alkylated dihydrocoumarins with up to 93:7 er, thanks to an enantioselective domino cyclization-decarboxylative-protonation reaction triggered by an unprecedented benzhydryl-derived cupreine organocatalyst. This cyclization sequence was extended to an emerging organocatalytic decarboxylative-chlorination reaction in the presence of trichloroquinolinone and by means of a bifunctional cinchona derived Br?nsted base which gave rise to the formation of dihydrocoumarins (up to 79:21 er) with a tertiary chlorinated stereocenter. (Figure presented.).
Organocatalytic annulation of aldehydes and o-quinone methides: A facile access to dihydrocoumarins
Zhou, Ding,Mao, Kaizhe,Zhang, Jian,Yan, Bingliang,Wang, Wei,Xie, Hexin
, p. 5649 - 5652 (2016/11/29)
A [4+2] annulation of aldehydes and o-quinone methides catalyzed by a secondary amine is developed. This process leads to biologically important dihydrocoumarins in moderate to good yields after oxidation. In addition, the employment of a chiral secondary amine catalyst allows access to optically active dihydrocoumarins with up to 64% ee.
N-Heterocyclic carbene-catalyzed enantioselective annulations: A dual activation strategy for a formal [4+2] addition for dihydrocoumarins
Lee, Anna,Scheidt, Karl A.
, p. 3407 - 3410 (2015/03/18)
A highly efficient asymmetric formal [4+2] annulation for the synthesis of dihydrocoumarins has been developed via an in situ activated NHC catalysis. Both electrophilic and nucleophilic species are generated in situ simultaneously whereby acyl imidazoles facilitated rapid formation of an NHC-enolate intermediate to afford the [4+2] dihydrocoumarin adducts.
