CATALYTIC INTERMOLECULAR HYDROACYLATION USING RHODIUM COMPLEX

我们在2004年报道了水杨醛与1，4-五或1，5-六-二烯在Rh催化剂作用下的分子间氢酰化反应，反应条件温和，得到了异氢酰化产物和正氢酰化产物的混合物。上述发现促使我们研究这一反应，以开发与立体选择性和区域选择性有关的实际合成反应。Rh催化的降冰片烯与水杨醛的π表面选择性分子间氢酰化反应实现了降冰片烯与水杨醛的π表面选择性氢酰化反应。在与降冰片烯的反应中，由于空间位阻的作用，选择性地生成了外氢酰化产物。在降冰片二烯的情况下，由于螯合作用，内切产物是立体选择性地获得的。此外，由于7-叔丁氧基降冰片二烯与7-叔丁氧基降冰片二烯的络合作用和远取代基效应，7-叔丁氧基降冰片二烯反应生成的产物为内切、共聚产物。从而实现了立体选择性的氢酰化反应。丁腈促进的Rh催化的烯烃与水杨醛的分子间氢酰化反应在室温下进行，水杨醛和烯基腈的分子间氢酰化反应优先得到正的氢酰化产物。乙腈和乙酸钠的加入加速了Rh催化单烯烃的氢酰化反应，在温和的反应条件下只生成正常的氢酰化产物。还提出了地区选举的合理反应机制。因此，该反应的通用性可以得到广泛的发展。

We reported in 2004 that an intermolecular hydroacylation between salicylaldehydes and 1,4-penta-or 1,5-hexa-dienes by Rh-catalyst proceeded under mild reaction conditions to give a mixture of iso-and normal-hydroacylated products. The above findings prompted us to study this reaction to develop a practical synthetic reaction in connection with stereoselectivity and regioselectivity.1. Rh-catalyzed π-facial selective intermolecular hydroacylation of norbornenesRh-catalyzed π-facial selective intermolecular hydroacylation of norbornenes with salicylaldehydes have been attained. In the reaction with norbornylene, the exo-hydroacylated product was produced selectively because of steric hindrance. In the case of norbornadiene, the endo-product was obtained stereoselectively because of chelation effect. Additionally, because of chelation effect and remote substituent effects, the product formed in the reaction of 7-tert-butoxynorbornadiene was the endo, syn-product. Thus, the stereoselective hydroacylation could be achieved.2. Nitrile-promoted Rh-catalyzed intermolecular hydroacylation of olefins with salicylaldehydeRh-catalyzed intermolecular hydroacylation of salicylaldehyde and alkenylnitriles has been found to proceed at room temperature and to preferentially give normal-hydroacylated products. Addition of acetonitrile and sodium acetate accelerated the Rh-catalyzed hydroacylationof monoolefines to exclusively produce the normal-hydroacylated products under miled reaction conditions. Plausible reaction mechanisms for the regioselections are also proposed. Thus, the generality of this reaction could be widely developed.