抄録
Asymmetric three-component 1,2-oxytrifluoromethylations of styrenes were explored by using N-oxyphthalimide (NOPI) as the resulting benzylic radical anchor after cross-coupling by a CF3 radical under the catalyses of chiral N-salicylidene-derived oxovanadium(V) complexes. Among the 15 different solvents and 15 different catalysts examined, the best scenarios were in i-PrOH with C3-tert-butyl or C3-fluoro-/2,5-dimethylphenyl-substituted vanadyl catalysts that led to the corresponding complementary S and R products in up to 88% yields and 87/86% ees, respectively, with further enrichment to at least 94% ee after a single recrystallization. The ccontrol α-(2-phenylcyclopropyl)styrene was tested to prove the asymmetric event involving the benzylic radical species. DFT computations showed that the SOMO of the benzylic radical is placed in a way to orient the CF3CH2 group away from the tert-butyl group in the salicylidene-l-tert-butylglycinate template by interacting with the N-oxygen atom of NOPI bound to the vanadium center with a bimolecular homolytic substitution (SH2) type mechanism. The enantioselectivity profile was dominated by several noncovalent interactions between the intermediary vanadium(NOPI) complex and the resulting benzylic radical.
本文言語 | 英語 |
---|---|
ページ(範囲) | 7160-7175 |
ページ数 | 16 |
ジャーナル | ACS Catalysis |
巻 | 11 |
号 | 12 |
DOI | |
出版ステータス | 出版済み - 6月 18 2021 |
外部発表 | はい |
!!!All Science Journal Classification (ASJC) codes
- 触媒
- 化学 (全般)