CATALYTIC INTERMOLECULAR HYDROACYLATION USING RHODIUM COMPLEX

我们在2004年报道了水杨醛和1,4-五或1,5-六-二烯在温和反应条件下通过铑催化剂进行分子间氢化反应，得到了异氢化和正常氢化产物的混合物。上述发现促使我们对该反应进行研究，以开发具有立体选择性和区域选择性的实用合成反应。研究了降冰片烯与水杨醛分子间的π-面选择性氢化反应。在与降冰片烯的反应中，由于空间位阻的存在，选择性地生成了外氢化产物。以降冰片二烯为例，由于螯合作用，内产物具有立体选择性。另外，由于螯合作用和远端取代基的作用，7-叔丁基降冰片二烯的反应产物为内同产物。因此，可以实现立体选择性氢化。腈促进的氢催化烯烃与水杨醛的分子间氢酰化反应在室温下进行，并优先得到正常氢酰化产物。乙腈和乙酸钠的加入加速了单烯烃的氢酰化反应，在较低的反应条件下只生成正常的氢酰化产物。并提出了区域选择的合理反应机制。因此，这种反应的普遍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.