铑催化烯烃氢甲酰化反应的密度泛函研究

在B3LYP／6-31G(d，P)(Rh和P采用LANL2DZ Polar)水平下，研究了有机膦羰基铑催化乙烯的氢甲酰化反应机理，优化了反应中间体、过渡态和产物的结构．结果表明，乙烯的氢甲酰化反应有两条主要的反应路径，经历了乙烯络合、乙烯插入、膦加成、羰基插入、H2的氧化加成和丙醛还原消除及催化剂的再生等过程．乙烯插入、羰基插入、H2的氧化加成和丙醛还原消除过程中三元环的形成是协同进行的．反应以顺式活性催化剂为起始物，H2的氧化加成是反应速度控制步骤，丙酰基的消除反应是不可逆的．理论结果与实验一致．

DFT Modeling Study of Ethylene Hydroformylation Catalyzed by Organic Phosphine-rhodium Catalyst

The ethylene hydroformylation catalyzed by the organic phosphinerhodium catalyst was computed by means of the density functional theory at the B3LYP/6-31G(d, p) level (Rh and P are at the LANL2DZ+Polar basis sets) and the structures for the intermediates, the transition states, and the products were optimized. As shown, there are two domination reaction paths for this reaction and it passes through coordination of ethylene to rhodium, ethylene insertion, addition of phosphine, carbonyl insertion, oxidative addition of H 2, and aldehyde reductive elimination with the regeneration of the catalyst. During the ethylene insertion, the carbonyl insertion, the oxidative addition of H 2, and the aldehyde reductive elimination, the three-membered structures are formed. As predicted, the hydroformylation originates from the cis-isomers of the catalyst, the oxidative addition of H 2 is the rate-determining step, and the aldehyde reductive elimination is un-reversed.