We report the development of a multicatalytic, one-pot, asymmetric Michael/Stetter reaction between salicylaldehydes and electron-deficient alkynes. The cascade proceeds via amine-mediated Michael addition followed by an
N
-heterocyclic carbene-promoted intramolecular Stetter reaction. A variety of salicylaldehydes, doubly activated alkynes, and terminal, electrophilic allenes participate in a one-step or two-step protocol to give a variety of benzofuranone products in moderate to good yields and good to excellent enantioselectivities. The origin of enantioselectivity in the reaction is also explored;
E
/
Z
geometry of the reaction intermediate as well as the presence of catalytic amounts of catechol additive are found to influence reaction enantioselectivity.
我们报道了一种多催化剂、一锅法、不对称的Michael/Stetter反应,用于将水杨醛和电子不足的炔烃进行级联反应。该反应级联进行,首先通过胺介导的Michael加成,然后通过一种N-杂环卡宾促进的分子内Stetter反应。多种水杨醛、双重活化的炔烃和末端亲电性烯烃参与了一步或两步的反应,产率中等至良好,对映选择性良好至优异,得到了多种苯并呋喃酮产物。还探讨了反应对映选择性的起源;反应中间体的E/Z几何构型以及催化量的邻苯二酚添加剂的存在被发现会影响反应的对映选择性。