Atmospheric Pressure Carbonylation of Allylic Compounds

钯催化的烯丙基化合物的羰基化反应提供了一种合成α，β-不饱和酸的方法。然而，由于它需要很高的一氧化碳压力，所以应用较少。早在几年前，我们就发现，在强碱存在的情况下，常压下的常压羰基化反应在室温下顺利进行。为了避免过量的碱，需要在烯丙基卤化物中缓慢地滴加醇钠。在本研究中，我们旨在简化反应程序和催化剂体系，并以肉桂氯为底物优化反应。作为AQ两相反应的催化剂。NaOH/有机溶剂pDCl2p[Ph_2p(m-C_6H_4SO_3Na)]_2的产率和CO吸收速率最好。我们考虑了一种可能性，即简单的羰化反应涉及CO插入Pd-O键，而不是Pd-C键。在均相CH_3ONa/CH_3OH体系的羰化反应中，无磷配体的Na_2PdCl_4‘-Gt；高产率地生成了甲酯。另一方面，钯与磷配体的络合物以甲醚为主要产物。磷配体的存在对羰化反应有很大影响，需要更多的工作来确定这种羰化反应的途径。

The palladium-catalyzed carbonylation of allylic compounds offers a synthetic method of alpha, beta-unsaturated acid. However, the carbonylation has found less application, because it requires a high carbon monoxide pressure. Several years ago we have found that the atmospheric pressure carbonylation proceeds smoothly at room temperature in the presence of strong bases such as or It was necessary to add sodium alkoxide slowly and dropwise to the allylic halides, to avoid an excess of the bases.In the present study we aimed at simplifying the reaction procedure and the catalyst system and optimizing the reaction using cinnamyl chloride as the substrate. As the catalyst of the biphasic reaction of aq. NaOH/organic solvent pDCl_2p[ph_2p(m-C_6H_4SO_3Na)]_2 gave the best results in terms of yield and rate of CO uptake. We considered a possibility that the facile carbonylation involved the CO insertion into a pd-O bond, rather than a pd-C bond. It seemed likely that this process occurs in the aqueous phase.In the carbonylation of the homogeneous CH_3ONa/CH_3OH system, Na_2PdCl_<4'> without any phosphorus ligand, gave methyl esters in high yields. On the other hand, palladium complexes with phosphorus ligand gave methyl ethers as the major product. The presence of the phosphorus ligand affects the carbonylations significantly.More work is needed to define the pathway of this carbonylation.