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.
A Clean, Facile and Practical Synthesis of α-OxoketeneS,S-Acetals in Water
作者:Yan Ouyang、Dewen Dong、Haifeng Yu、Yongjiu Liang、Qun Liu
DOI:10.1002/adsc.200505331
日期:2006.1
A clean, facile and practical synthesis of α-oxoketene S,S-acetals in water has been developed. Catalyzed by tetrabutylammonium bromide (TBAB) at room temperature in water, a range of β-dicarbonyl compounds have been converted to the corresponding α-oxoketene S,S-acetals in very high yields. The catalyst in the aqueous phase can be recycled after the separation of organic products.
A new route to extended tetrathiafulvalenes from α-acetyl ketene-S,S-acetals
作者:Yu-Long Zhao、Wei Zhang、Ji-Qing Zhang、Qun Liu
DOI:10.1016/j.tetlet.2006.02.128
日期:2006.5
extended tetrathiafulvalenes was described. The extended TTFs with hexa-2,4-diyne-1,6-diylidene spacer between the two 1,3-dithiole rings were prepared simply from the easily available α-acetyl ketene-(S,S)-acetals in good yields under mild conditions.
Domino Reaction of α-Acetyl-α-carbamoyl Ketene Dithioacetals with Vilsmeier Reagents: A Novel and Efficient Synthesis of 4-Halogenated 2(1<i>H</i>)-Pyridinones
A novel and efficient route to 4-halogenated N-substituted 2(1H)-pyridinones has been developed via a one-pot domino process of readily available α-acetyl-α-carbamoyl ketene dithioacetals with Vilsmeier reagents. These 4-halogenated-2(1H)-pyridinones constitute useful intermediates due to the easy elaboration on either the pyridinone core (by the displacement of the halogen atom) or functionality transformation