A water-soluble Brønstedacid, 5-sulfosalicylic acid, efficiently catalyzed the direct three-component Mannich reactions of cyclohexanone and 3-pentanone in pure water. 21 Examples of Mannich reactions were presented, which afforded the corresponding β-amino ketones with up to 97% yield and decent diastereoselectivities. The acid catalyst can be recycled as an aqueous solution for at least six times
Starch sulfonic acid was used as efficient and highly stereoselective catalyst for the three-component Mannich reaction of aldehydes, amines, and ketones in water at ambient temperature to afford the corresponding β-amino ketones in good to excellent stereoselectivity and yields.
BromodimethylsulfoniumbromidecatalyzesMannich-typereactions of a variety of aldimines, generated in situ from aldehydes and anilines, with enolizable ketones or diethyl malonate in three-componentreactions to afford the corresponding β-amino carbonyl compounds. The salient features of this protocol are: shorter reaction times, simplicity of the procedure, good to excellent yields, avoidance of
Stereoselective synthesis of β-amino ketones via direct Mannich-type reaction catalyzed with silica sulfuric acid
作者:Hui Wu、Yang Shen、Li-yan Fan、Yu Wan、Pu Zhang、Cai-fa Chen、Wen-xiang Wang
DOI:10.1016/j.tet.2007.01.015
日期:2007.3
At room temperature, the direct Mannich-type reaction of a variety of in situ generated aldimines using aldehydes and anilines with ketones in a three-component reaction was efficiently catalyzed by silica sulfuricacid (SSA) in EtOH. This rapid reaction afforded the corresponding β-amino ketones in good yields with excellent stereoselectivities and catalyst was recyclable.
heterogeneous catalyst for the Mannich reaction. One-pot multi-component condensation of an aldehyde, an amine and a ketone at ambient temperature affords the corresponding β-amino ketones using novel nano-sized Rb2HPW12O40. Simple purification, short reaction time and high yield are some of the advantages of this reaction. Also, the catalyst can be readily isolated. The nano catalyst Rb2HPW12O40 has