Beilstein J. Org. Chem.2012,8, 1485–1498, doi:10.3762/bjoc.8.168
Organic Chemistry I, University of Erlangen-Nuremberg, Henkestraße 42, 91054, Erlangen, Germany 10.3762/bjoc.8.168 Abstract A new guanidine-thiourea organocatalyst has been developed and applied as bifunctional organocatalyst in the Michael addition reaction of diethyl malonate to trans-β-nitrostyrene
. Extensive DFT calculations, including solvent effects and dispersion corrections, as well as ab initio calculations provide a plausible description of the reaction mechanism.
Keywords: bifunctional organocatalyst; DFT calculations; guanidine-thiourea; Michael addition; organocatalysis; transition states
guanidine-thiourea organocatalysts would perform as well as or even better than amine-thioureas and imidazole-thioureas. Generally, guanidines are well-known basic catalysts in organic synthesis, but only scattered examples of chiral guanidines as organocatalysts are known [49]. Indeed, only one guanidine
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Graphical Abstract
Scheme 1:
Synthesis of guanidine-thiourea organocatalyst 7.