We report a new organocatalytic cascade reaction. A combination of the amine substrate with a catalytic amount of a Brønsted acid merges enamine and iminium catalysis with Brønsted acid catalysis in a new organocatalytic cascade reaction. We found that the aniline substrate itself in combination with a catalytic amount of PTSA·H2O can function as an aminocatalyst accomplishing an aldol condensation-conjugate reduction cascade, which terminates in a Brønsted acid catalyzed reductive amination incorporating the amine substrate into the final product. This transformation furnishes trans-3-substituted cyclohexyl amines in good yields and good diastereoselectivities.
我们报告了一种新的有机催化级联反应。胺底物与催化量的布氏酸相结合,在一个新的有机催化级联反应中将烯胺催化和
亚胺催化与布氏酸催化合二为一。我们发现,
苯胺底物本身与催化量的
PTSA-
H2O 结合可作为胺催化剂,完成醛醇缩合-共轭物还原级联反应,最后在布氏酸催化下还原胺化,将胺底物纳入最终产物。这一转化过程能以良好的产率和非对映选择性生成反式-3-取代的
环己胺。