Stereoselective Synthesis of β-Amino Ketones via Direct Mannich-Type Reactions, Catalyzed with ZrOCl2·8H2O under Solvent-Free Conditions
作者:Bagher Eftekhari-Sis、Amir Abdollahifar、Mohammed M. Hashemi、Maryam Zirak
DOI:10.1002/ejoc.200600493
日期:2006.11
zirconium oxychloride (ZrOCl2·8H2O) efficiently catalyzes the directMannich-typereaction of a variety of in situ generated aldimines using aldehydes and anilines with ketones in a three-componentreaction under solvent-free conditions. The reaction proceeds rapidly and affords the corresponding β-aminoketones in good to high yields with good to excellent stereoselectivities. The catalyst can be recycled
A new binary acid system featuring an air stable organometallic precursor, titanocene dichloride and a simple Brønsted acid–base compound, was developed. The new catalyst system allowed for mild and highly efficient direct three-component Mannich reactions of both aryl ketones and alkyl ketones, in particular, acetone and its derivatives with excellent yields. Mechanistic study elucidated the dramatic synergistic effect of the new binary acid system.