The simple tetraminocalixarene 1, which contains weak H-bond-donor NH2 groups, is reported to be a highly efficient organocatalyst for the Vinylogous Mukaiyama Aldol Reaction (VMAR) of 2-(trimethylsilyloxy)furan 5 with a-ketoesters 6a–l under “on-water” conditions owing to the hydrophobic amplification of weak H-bond interactions. The catalytic efficiency of calixarene catalyst 1 was shown to be closely related to its recognition abilities towards the reactants 5 and 6 through a multipoint recognition model. The proposed model provided good explanations for the differences on the reaction rate acceleration and on the stereoselectivity observed with different substrates.
|Titolo:||A Simple Tetraminocalixarene as a Highly Efficient Catalyst under “On-Water” Conditions through Hydrophobic Amplification of Weak Hydrogen Bonds|
|Data di pubblicazione:||2017|
|Appare nelle tipologie:||1.1.2 Articolo su rivista con ISSN|