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A Combined IM‐MS/DFT Study on [Pd(MPAA)]‐Catalyzed Enantioselective CH Activation: Relay of Chirality through a Rigid Framework |
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| Authors: | Gui‐Juan Cheng Ping Chen Tian‐Yu Sun Dr Xinhao Zhang Prof Dr Jin‐Quan Yu Prof Dr Yun‐Dong Wu |
| Institution: | 1. Lab of Computational Chemistry and Drug Design, Key Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, Shenzhen 518055 (P.R. China);2. Department of Chemistry, The Scripps Research Institute, California 92037 (USA);3. College of Chemistry, Peking University, Beijing 100871 (P.R. China) |
| Abstract: | A combined ion‐mobility mass spectrometry (IM‐MS) and DFT study has been employed to investigate the mechanism and the origin of selectivity of palladium/mono‐N‐protected amino acid (MPAA)‐catalyzed enantioselective C?H activation reactions of several prochiral substrates. We captured the Pd(MPAA)(substrate)] complex at different stages, and demonstrated that the C?H bond can be activated in the absence of an external base. DFT studies lead to the establishment of a significantly modified relay mechanism invoking a key conformational effect to account for the origin of enantioselectivity. This relay mechanism successfully accounts for the enantioselectivity for all the relevant reactions reported. The enantioselectivity originates from the rigid square‐planar Pd coordination in the C?H activation transition state: Bidentate MPAA and substrate coordination. |
| Keywords: | amino acids asymmetric catalysis C H activation density functional calculations enantioselectivity mass spectrometry |