Highly Efficient Aza-Michael Reactions of Enones with Carbamates Using a Combination of Quaternary Ammonium Salts and BF<sub>3</sub>·OEt<sub>2</sub>as a Catalyst
作者:Chun-Gu Xia、Li-Wen Xu、Lyi Li、Shao-Lin Zhou、Jing-Wei Li、Xiao-Xue Hu
DOI:10.1055/s-2003-43333
日期:——
Aza-Michael reactions of enones with carbamates took efficiently in the presence of a catalytic amount of quaternary ammonium salts and BF 3 .OEt 2 to afford the total products in high yields. The new catalytic system was also efficient in the aza-Michael reaction of chalcone, which was difficult to react with carbamates by transition metal salts catalysts.
Heteropoly Acids Catalyzed Direct Mannich Reactions: Three-Component Synthesis of N-Protected β-Amino Ketones
作者:Xiaoxia Lu、Rui Wang、Taikun Huang、Lin Shi、Bogang Li
DOI:10.1055/s-2007-984913
日期:——
catalyzed one-pot three-component Mannich reactions of aryl aldehydes, aryl ketones, and carbamates at ambient temperature and afforded the corresponding N-protected beta-amino ketones in good to excellent yields. This method provides a novel and improved modification of three-component Mannich reactions in terms of a wide scope of aldehydes, ketones and carbamates, economic viability and reusability.
Transition Metal Salt-Catalyzed Direct Three-Component Mannich Reactions of Aldehydes, Ketones, and Carbamates: Efficient Synthesis of N-Protected β-Aryl-β-Amino Ketone Compounds
作者:Li-Wen Xu、Chun-Gu Xia、Lyi Li
DOI:10.1021/jo048778g
日期:2004.11.1
three-component Mannich reactions of aryl aldehydes, aryl ketones, and carbamates are described. The RuCl3·xH2O-, AuCl3−PPh3-, and AuCl3-catalyzed direct Mannich reactions led to the synthesis of N-protected β-aryl-β-amino ketones, and the results create new possibilities for exploiting the transition metal salt-catalyzed direct Mannich reaction and facile synthesis of β-amino ketone libraries.
描述了过渡金属盐催化的芳基醛,芳基酮和氨基甲酸酯的直接三组分曼尼希反应。RuCl 3 · x H 2 O-,AuCl 3 -PPh 3-和AuCl 3催化的直接曼尼希反应导致N保护的β-芳基-β-氨基酮的合成,其结果为开发新的可能性提供了可能性过渡金属盐催化的直接曼尼希反应,并且易于合成β-氨基酮库。
Improved Protocol for the Three-ComponentBiginelli Reactions andBiginelli-LikeMannich Reactions of Carbamates, Aldehydes, and Ketones
A mild, convenient, and improved method for the direct three-component Biginelli and Biginelli-like Mannich-type reactions of carbonyl compounds in the presence of inexpensive FeCl3⋅6 H2O and Me3SiCl as catalysts is described. Reactions performed with carbamates can be used to directly access N-protected β-amino carbonyl compounds in a single step.
Hf(OTf)4-Catalyzed Three-Component Synthesis of N-Carbamate-Protected β-Amino Ketones
作者:Zhen-Zhen Chen、Dong-Zhao Yang、Ying-Ying Dong、Mei Chi、Shou-Zhi Pu、Qi Sun
DOI:10.3390/molecules27031122
日期:——
been identified as a potent catalyst for the direct three-component synthesis of β-carbamate ketones. This new method, featuring a low catalyst loading, fast reaction rate, and solvent-free conditions, provided facile access to a diversity of carbamate-protected Mannich bases. A mechanistic investigation indicated that the three-component reaction proceeds via sequential aldol condensation and aza-Michael