【摘要】 2013年,许秀芳、Houk和唐卫平课题组合作报道了Rh（PPh₃）₃Cl催化3-酰氧基-1,4-烯炔（ACE）和炔烃的（5+2）环加成形成环庚三烯的反应机理,他们的研究表明该机理包括1,2-羧基迁移、炔烃插入、还原消除等一系列步骤,其中1,2-羧基迁移是决定反应速率的步骤.本文利用密度泛函理论（DFT）计算预测了将价格相对便宜的Ir（PPh₃）₃Cl催化剂应用于ACE和炔烃分子间（5+2）环加成反应制备七元碳环的可行性.计算结果表明,利用Ir（PPh₃）₃Cl催化剂合成七元碳环是一种方便、高效、实用的方法,且改变催化剂并不改变反应的机理和区域选择性,而是改变了反应的决速步.更多还原

【Abstract】 The mechanism of Rh（PPh₃）₃ Cl-catalyzed（5+2） cycloadditions of 3-acyloxy-1,4-enyne（ACE） and alkynes had been reported by Xu, Houk and Tang et al. in 2013. Their investigation revealed that the mechanism involved sequential steps of 1,2-acyloxy migration, alkyne insertion, and reductive elimination to form the cycloheptatriene product, and 1,2-acyloxy migration was found to be the rate-determining step. Herein, we used density functional theory（DFT） calculations to predict the plausibility of applying the relatively cheaper Ir（PPh₃）₃ Cl catalyst to the intermolecular（5+2） cycloadditions of 3-acyloxy-1,4-enyne and alkynes to produce seven-membered carbocycles. The calculation results suggest a convenient and energetically practical approach to synthesize seven-membered carbocycle using the Ir-（PPh₃）₃ Cl catalyst. In addition, the calculation results suggest that altering the catalyst does not change the mechanism of the reaction and preferences for the regioisomeric products, but does change the rate-determining step.更多还原