A Frustrated and Confused Lewis Pair |
| |
| Authors: | Dr. Alison C. McQuilken Quang Minh Dao Dr. Allan Jay P. Cardenas Dr. Jeffery A. Bertke Prof. Dr. Stefan Grimme Prof. Dr. Timothy H. Warren |
| |
| Affiliation: | 1. Department of Chemistry, Georgetown University, Washington, DC, USA;2. Mulliken Center for Theoretical Chemistry, Institut für Physikalische Chemie und Theoretische Chemie, Universit?t Bonn, Bonn, Deutschland;3. Department of Chemistry, State University of New York at Fredonia, Fredonia, NY, USA |
| |
| Abstract: | We report a new class of frustrated Lewis pairs (FLPs) by the hydroboration of bulky isocyanates iPr2ArNCO (iPr2Ar=2,6‐iPr2C6H3) and Ph2tBuArNCO (Ph2tBuAr=2,6‐Ph2‐4‐tBuC6H2) with Piers’ borane (HB(C6F5)2). While hydroboration of smaller isocyanates such as iPr2ArNCO leads to isocyanate—N/B FLP adducts, hydroboration of the bulkier Ph2tBuArNCO allows isolation of the substrate‐free aminoborane with a short, covalent N?B bond. This confused FLP reversibly binds unsaturated substrates such as isocyanates and isocyanides, suggesting the intermediacy of a “normal” FLP along the reaction pathway, supported by high‐level DFT studies and variable‐temperature NMR spectroscopy. These results underscore the possibility of FLP behavior in systems that possess no obvious frustrated Lewis acid–base interaction. |
| |
| Keywords: | density functional calculations frustrated Lewis pairs hydroboration acid– base interactions sustainable chemistry |
|
|
