取代基对有机金属铼化合物中分子内α-氢转移反应势垒的影响

使用B3LYP方法研究了有机铼化合物R³R⁵(NHR⁴)Re(＝CHR¹)(＝NR²)中分子内α-氢转移反应, 探讨了不同取代基对α-氢转移反应势垒的影响. 研究发现, 可以通过改变取代基来影响过渡金属Re有机化合物中的α-氢转移反应. R¹位置的取代基为Me或CMe₃时, 可以较大程度降低α-氢转移反应的势垒. R²为H时, α-氢转移反应势垒最低. R³和R⁵位置为SiH₃时的反应势垒最低. R⁴为CMe₃时, α-氢转移反应势垒最低. 研究结果还表明, 取代基对于反应势垒的影响有加和性.

Effects of Substituents on the Reaction Barriers of the Intramolecular α-Hydrogen Transfer in Organometallic Rhenium Complexes

The theoretical calculations on a series of intramolecular α-hydrogen transfer reactions in organometallic rhenium complexes R³R⁵(NHR⁴)Re(＝CHR¹)(＝NR²) were carried out with B3LYP method and the effects of substituents on the barriers of the α-hydrogen transfer reactions were explored. It was found that the most preferable substituents are methyl or t-butyl groups for R¹ while the hydrogen atom is the best one for R². For R³ and R⁴, the most suitable groups are silyl and t-butyl groups, respectively. Calculation results also show that additivity exists for the effects of substituents on the barriers of the α-hydrogen transfer reactions.