化学
SN2反应
亲核细胞
区域选择性
催化作用
芳基
亲核取代
药物化学
组合化学
计算化学
有机化学
烷基
作者
Hailing He,Jiying Liu,Tao Wang,Limin Guo,Wenjing Zhang,Xuebo Chen
标识
DOI:10.1016/j.mcat.2023.113111
摘要
Selective CF bond activation and functionalization of readily available polyfluorinated groups is a classical and effective way to access high value-added organofluorine compounds. Insights into origin of the selectivities could provide valuable guidance to precise manipulation and so as to get desired products. In this study, the mechanism and causation of the selective mono-CF bond allylation of trifluoromethylalkenes with tetrabutylammonium fluoride (TBAF) as catalyst has been investigated by using the density functional theory (DFT) methods. It is unveiled that the SN2′-type nucleophilic substitution going through the addition-elimination mechanism is more favorable than the concerted SN2 pathway. According to the calculation results, allyl anions would kinetically identify the trifluoromethylalkene, ammonium cation (TBA+), and difluoromethylalkene in turn, which guarantees the mono-CF bond activation under the conditions of excessive nucleophiles. Furthermore, as a specific point, the regioselectivity of the reaction using asymmetric allyl anion as the nucleophile has also been studied. The Parr function calculations and non-covalent interaction analysis reveals that the more significant nucleophilicility of the benzyl carbon atom in allyl anion and the π…π interaction between the aryl substituents on the two reacting fragments leads to favor of the reaction at the benzyl site.
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