Intramolecular Aza-Anti-Michael Addition of an Amide Anion to Enones: A Regiospecific Approach to Tetramic Acid Derivatives
作者:Xihe Bi、Jingping Zhang、Qun Liu、Jing Tan、Bing Li
DOI:10.1002/adsc.200600542
日期:2007.10.8
A novel intramolecular aza-anti-Michael addition was disclosed in the one-pot reactions between 3-oxobutanamides and aryl (heteroaryl) aldehydes under basic conditions, in which amide anions regiospecifically attacked the α-carbon of an enone fragment, providing a newroute to biologically important tetramic acid derivatives. An explanation for the unexpected regioselectivity is proposed based on the
A facile and efficient one-pot synthesis of substituted pyridine-2,4(1H,3H)-diones has been developed. Subjected to N,N-dimethylformamide dimethyl acetal (DMFDMA) in N,N-dimethylformamide at 120 ˚C, a series of acyl(carbamoyl)ketene S,S-acetals were converted into the corresponding substituted pyridine-2,4(1H,3H)-diones in high yields.
Catalytic Synthesis of α-Oxoketene S,S-Acetals in a Wet Ionic Liquid [Bmim]Cl/H2O Homogeneous System
作者:Ping Yu、Yuangang Zu、Yujie Fu、Thomas Efferth
DOI:10.3390/molecules16064500
日期:——
A clean, practical and environmentally friendly synthesis in a homogeneous system has been developed for α-oxoketene S,S-acetals. A mixture of [Bmim]Cl and water was used as medium. The best economical and practical molar ratio of [Bmim]Cl to substrate was 4 to 1. With various types of 1,3-dicarbonyl compounds as substrate, the corresponding α-oxoketene S,S-acetals have been prepared under mild reaction
A tandem reaction of 2-acetylmethylene-1,3-dithiolanes via fragmentation of the dithiolane ring in the presence of amines: a facile route to functionalized thioamides
作者:Fushun Liang、Yan Li、Dazhi Li、Xin Cheng、Qun Liu
DOI:10.1016/j.tetlet.2007.09.065
日期:2007.11
A facile and efficient route to functionalized thioamides has been developed by a tandem reaction of 2-acetylmethylene-1,3-dithiolanes via fragmentation of the dithiolane ring upon heating and in the presence of an amine.
Intramolecular Thia-anti-Michael Addition of a Sulfur Anion to Enones: A Regiospecific Approach to Multisubstituted Thiophene Derivatives
作者:Yan Li、Fushun Liang、Xihe Bi、Qun Liu
DOI:10.1021/jo0611420
日期:2006.10.1
The intramolecular thia-anti-Michael addition starting from readily available α-alkenoyl-α‘-carbamoyl ketene-(S,S)-acetals 1 containing a 1,3-dithiolane moiety was developed. In particular, in the presence of aliphatic primary amines, a series of tetrasubstituted thiophene derivatives, 2-(alkylamino)-5-alkyl-4-hydroxythiophene-3-carboxamides 2, were synthesized via tandem fragmentation, substitution