A Cooperative Participation of the Amido Group in the Organocatalytic Construction of All-Carbon Quaternary Stereocenters by Michael Addition with β-Ketoamides
作者:Maria del Mar Sanchez Duque、Olivier Baslé、Nicolas Isambert、Anouk Gaudel-Siri、Yves Génisson、Jean-Christophe Plaquevent、Jean Rodriguez、Thierry Constantieux
DOI:10.1021/ol200924e
日期:2011.7.1
The secondary amido group of a-substituted beta-ketoamides plays a crucial role in the control of the reactivity and spatial arrangement (selectivity) in the organocatalyzed Michael addition to unsaturated carbonyls. This results in an unprecedented activation mode of substrates through H-bonding interactions allowing the construction of enantiomerically enriched functionalized all-carbon quaternary centers and spiroaminals of high synthetic potential.
Origin of the Enantioselectivity in Organocatalytic Michael Additions of β-Ketoamides to α,β-Unsaturated Carbonyls: A Combined Experimental, Spectroscopic and Theoretical Study
作者:Adrien Quintard、Diana Cheshmedzhieva、Maria del Mar Sanchez Duque、Anouk Gaudel-Siri、Jean-Valère Naubron、Yves Génisson、Jean-Christophe Plaquevent、Xavier Bugaut、Jean Rodriguez、Thierry Constantieux
DOI:10.1002/chem.201404481
日期:2015.1.7
The organocatalytic enantioselective conjugate addition of secondary β‐ketoamides to α,β‐unsaturated carbonyl compounds is reported. Use of bifunctional Takemoto’s thiourea catalyst allows enantiocontrol of the reaction leading either to simple Michael adducts or spirocyclic aminals in up to 99 % ee. The origin of the enantioselectivity has been rationalised based on combined DFT calculations and kinetic