Facile Synthesis of δ-Amino-β-ketoesters and Piperidinediones via a Vinylogous Mannich-Type Reaction of Brassard-Type Diene with Aldimines without Catalyst
摘要:
The vinylogous Mannich reaction of N-tosyl-aldimines with Brassard diene proceeds at room temperature under catalyst-free conditions smoothly to give gamma-amino-beta-ketoesters (4b-l) in good to excellent yields, which are easily converted to piperidinediones at higher temperature. The two-step reactions could be combined in a one-pot process with toluene as a solvent and without the use of any catalyst for direct synthesis of piperidinediones (5).
Molecular sieve mediated decarboxylative Mannich and aldol reactions of β-ketoacids
作者:Fangrui Zhong、Chunhui Jiang、Weijun Yao、Li-Wen Xu、Yixin Lu
DOI:10.1016/j.tetlet.2013.06.030
日期:2013.8
A molecular sieve mediated decarboxylativeMannichreaction of β-ketoacids with sulfonyl imines is reported; this protocol leads to an efficient preparation of synthetically useful β-amino ketones. An analogous molecular sieve promoted decarboxylative aldol reaction between β-ketoacids and isatins is also described, which affords bioactive 3-substituted-3-hydroxy-oxindoles in excellent yields.
Base-catalyzed three-component direct Mannich reaction of enolizable ketones with high syn-selectivities
作者:Qunsheng Guo、John Cong-Gui Zhao、Hadi Arman
DOI:10.1016/j.tetlet.2012.06.140
日期:2012.9
The three-component direct Mannichreaction between aldehydes, p-toluenesulfonamide, and enolizable ketones was achieved for the first time with organic bases as the catalysts. The corresponding N-tosylated β-aminoketones were obtained in high yields and good to excellent diastereoselectivities using TMG as the catalyst. Through reduction of the ketone group, the reaction product may be converted into