Tunable and Diastereoselective Brønsted Acid Catalyzed Synthesis of β-Enaminones
作者:Ye-Won Kang、Yu Jin Cho、Seung Jin Han、Hye-Young Jang
DOI:10.1021/acs.orglett.5b03445
日期:2016.1.15
The Brønsted acid catalyzed Meyer–Schuster reaction of hemiaminals was studied for the stereoselective synthesis of β-enaminones. Hemiaminals were formed from propargyl aldehydes (or the oxidation of propargyl alcohols) and amines in the presence of Brønsted acids. A critical step to control the stereochemistry of the products is the protonation of the corresponding allenol intermediate, which is dictated
A convenient one-pot strategy for the regioselective synthesis of cis-β-enaminones has been developed via the condensation of propiolaldehydes and amines in EtOH. This process has opened a new synthetic route to enamines in good yield. A possible reaction mechanism involving a Michael addition/enol tautomerization via a six-membered ring transition state is proposed.