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A Strategy to Control the Reactivation of Frustrated Lewis Pairs from Shelf‐Stable Carbene Borane Complexes |
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| Authors: | Dr Yoichi Hoshimoto Takuya Kinoshita Prof?Dr Masato Ohashi Prof?Dr Sensuke Ogoshi |
| Institution: | 1. Department of Applied Chemistry, Faculty of Engineering, Osaka University, Suita, Osaka 565‐0871 (Japan);2. Frontier Research Base for Global Young Researchers, Graduate School of Engineering, Osaka University, Suita, Osaka 565‐0871 (Japan);3. JST, ACT‐C, Suita, Osaka 565‐0871 (Japan) |
| Abstract: | N‐Phosphine oxide substituted imidazolylidenes (PoxIms) have been synthesized and fully characterized. These species can undergo significant changes to the spatial environment surrounding their carbene center through rotation of the phosphine oxide moiety. Either classical Lewis adducts (CLAs) or frustrated Lewis pairs (FLPs) are thus formed with B(C6F5)3 depending on the orientation of the phosphine oxide group. A strategy to reactivate FLPs from CLAs by exploiting molecular motions that are responsive to external stimuli has therefore been developed. The reactivation conditions were successfully controlled by tuning the strain in the PoxIm–B(C6F5)3 complexes so that reactivation only occurred above ambient temperature. |
| Keywords: | frustrated Lewis pairs hydrogenation N‐heterocyclic carbenes phosphine oxides |