Synthesis of <i>trans</i>-3-Substituted Cyclohexylamines via Brønsted Acid Catalyzed and Substrate-Mediated Triple Organocatalytic Cascade Reaction
作者:Benjamin List、Jian Zhou
DOI:10.1055/s-2007-984877
日期:——
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。