Reactions of N-substituted pyridinium carbamoylmethylenides with ethyl arylidenecyanoacetates
作者:T. S. Kuptsova、A. M. Shestopalov
DOI:10.1007/s11172-010-0016-4
日期:2009.2
Condensation of pyridinium N-alkyl-, N-cycloalkyl-, N-benzyl-, and N-phenethylcarb-amoylmethylenides with ethyl arylidenecyanoacetates stereoselectively gives 4,5-trans-1-alkyl-, 4,5-trans-l-cycloalkyl-, 4,5- trans-1-benzyl-, and 4,5-trans-1-phenethyl-4-aryl-3-cyano-6-oxo-5-(3-R-1-pyridinio)-1,4,5,6-tetrahydropyridin-2-olates. However, pyridinium N-arylcarb-amoylmethylenides react with the same esters without ring closure, yielding Michael adducts, viz., ethyl 3-aryl-4-(N-arylcarbamoyl)-2-cyano-4-(1-pyridinio)butyrates.
将吡啶鎓 N-烷基、N-环烷基、N-苄基和 N-苯乙基羰基氨基甲酰亚甲基烯化物与亚芳基氰基乙酸乙酯立体选择性缩合,可得到 4、5-trans-1-alkyl-, 4,5-trans-l-cycloalkyl-, 4,5- trans-1-benzyl-, and 4,5-trans-1-phenethyl-4-aryl-3-cyano-6-oxo-5-(3-R-1-pyridinio)-1,4,5,6-tetrahydropyridin-2-olates.然而,吡啶鎓 N-芳基氨基甲酰亚胺与相同的酯类发生反应而不闭环,会产生迈克尔加合物,即 3-芳基-4-(N-芳基氨基甲酰基)-2-氰基-4-(1-吡啶)丁酸乙酯。