A Convenient Regioselective Synthesis of Mannich Bases
作者:C. Rochin、O. Babot、J. Dunogues、F. Duboudin
DOI:10.1055/s-1986-31742
日期:——
A new, convenient regioselective process for aminomethylation of ketones is reported, involving the in situ formation of silyl enol ethers and iminium salts.
报道了一种新的、便捷的酮类化合物氨甲基化区域选择性过程,该过程涉及硅烷基烯醇醚和亚胺盐的现场生成。
Palladium-Promoted Transformation of β-Amino Ketones to Enaminones
作者:Shun-Ichi Murahashi、Yo Mitsue、Tatsuo Tsumiyama
DOI:10.1246/bcsj.60.3285
日期:1987.9
The reaction of β-amino ketones with bis(acetonitrile)dichloropalladium(II) in the presence of triethylamine gives the corresponding enaminones regioselectively. The cyclic β-amino ketones can be converted into the corresponding exocyclic enaminones. The enaminones thus obtained are versatile synthetic intermediates. The reaction of (E)-enaminones with organocuprates gave the corresponding (E)-α,β-unsaturated ketones.
Mannich bases react thermally with ketones to give 1,5-diketones by what appears to be a Michael reaction. In some cases the orientation of the product differs significantly from that observed in the Michael reaction, and Mannich bases lacking a hydrogen β to the N atom are able to react via an intermediate migration.
corresponding Mannich products by various dimethyl(methylene)ammonium salts under a range of reaction conditions. The several methods used to form these derivatives are compared. Excellent approaches to aldehyde derivatives involve treating the enol silyl ether of the carbonyl compound with methyllithium and then an iminium salt, or directly adding the iminium salt to the enol silyl ether. Ketones may be
Aminoketones were trifluoromethylated by using trialkyl(trifluoromethyl)silanes without any reaction promoters. Formation of cyclic intermediates is proposed to be possible transition states in this reaction. Moderate diastereoselectivities were observed in the trifluoromethylation of the aminoketones having a side chain.