A great variety of imines were efficiently isolated in high yields from the reaction of aldehydes and amines in ionic liquids. The ionic liquids could be recovered and reused for at least five cycles without loss in the yields being a useful alternative to dichloromethane or diethyl ether, which are the commonly used solvents for this reaction.
Cation Radical Aza-Diels-Alder Reaction between <i>N</i>-Arylimines and <i>N</i>-Vinyllactams: A Facile Synthesis of 4-Lactam-<i>N</i>-yl Tetrahydroquinolines
作者:Xiaodong Jia、Li Yang、Bing Han、Wei Zhang、Xiaoling Jin、Zhong-Li Liu
DOI:10.1055/s-2006-942521
日期:2006.9
Cycloaddition of N-arylimines with N-vinylpyrrolidin-2-one or N-vinylazepan-2-one was efficiently induced by tris(4-bromophenyl)aminium hexachloroantimonate producing stereoselectively the corresponding cis-2-aryl-4-(2-oxopyrrolidin-1-yl)- or cis-2-aryl-4-(2-oxoazepan-l-yl)tetrahydroquinoline derivative in good yields.
A general and versatile synthesis of 3-phenylthio β-lactams as lead molecules for 3-methyl-2-azetidinones
作者:Seema Kanwar、S. D. Sharma
DOI:10.1002/jhet.5570440523
日期:2007.9
Ketene-imine cycloaddition using phosphorus oxychloride and benzenesulfonyl chloride under the described reaction conditions yielded trans 3-phenylthio 2-azetidinones in good yields. Desulfurization using Raney nickel and alkylation finally afforded trans 3-methyl-2-azetidinones in a stereoselective manner.
Fast and Efficient Synthesis of Pyrano[3,2-<i>c</i>]quinolines Catalyzed by Niobium(V) Chloride
作者:Mauricio Constantino、Luiz da Silva-Filho、Valdemar Lacerda Júnior、Gil da Silva
DOI:10.1055/s-2008-1067186
日期:2008.8
A highly efficient two-step method for the synthesis of pyranoquinoline derivatives from imino-Diels-Alder reactions between aldimines and 3,4-dihydro-2H-pyran using niobium(V) chloride as catalyst under mild conditions is described.
We describe a titanium-mediated reaction for the convergent coupling of allenic alcohols with aromatic imines. Overall, the bond formation occurs at the central carbon of the allene, proceeds with net allylic transposition, and provides substituted 1,3-dienes bearing allylic amine functionality in a regio- and stereoselective fashion.