1599475-61-2Relevant academic research and scientific papers
The Chemistry of a Non-Interacting Vicinal Frustrated Phosphane/Borane Lewis Pair
Elmer, Lisa-Maria,Kehr, Gerald,Daniliuc, Constantin G.,Siedow, Melanie,Eckert, Hellmut,Tesch, Matthias,Studer, Armido,Williams, Kamille,Warren, Timothy H.,Erker, Gerhard
supporting information, p. 6056 - 6068 (2017/05/05)
The dimesitylphosphinocyclopentene/HB(C6F5)2-derived vicinal trans-1,2-P/B frustrated Lewis pair (FLP) 4 shows no direct phosphane–borane interaction. Toward some reagents it behaves similar to an intermolecular FLP; it cleaves dihydrogen, deprotonates terminal alkynes, and adds to organic carbonyl compounds including CO2. It shows typical intramolecular FLP reaction modes (cooperative 1,1-additions) to mesityl azide, to carbon monoxide, and to NO. The latter reaction yields a persistent P/B FLPNO nitroxide radical, which undergoes H-atom abstraction reactions. The FLP 4 serves as a template for the CO reduction by [HB(C6F5)2] to generate a FLP-η2-formylborane. The formylborane moiety is removed from the FLP template by reaction with pyridine to yield a genuine pyridine stabilized formylborane that undergoes characteristic borane carbaldehyde reactions (Wittig olefination, imine formation). Most new products were characterized by X-ray diffraction.
Formylborane formation with frustrated Lewis pair templates
Sajid, Muhammad,Kehr, Gerald,Daniliuc, Constantin G.,Erker, Gerhard
supporting information, p. 1118 - 1121 (2014/03/21)
Boranes R2BH react with carbon monoxide by forming the respective borane carbonyl compounds R2BH(CO). The formation of (C6F5)2BH(CO) derived from the Piers borane, HB(C6F5)2, is a typical example. Subsequent CO-hydroboration does not take place, since the formation of the formylborane is usually endothermic. However, an η2-formylborane was formed by CO-hydroboration with the Piers borane at vicinal phosphane/borane frustrated Lewis pair (FLP) templates. Subsequent treatment with pyridine liberated the intact formylborane from the FLP framework, and (pyridine)(C 6F5)2B-CHO was then isolated as a stable compound. This product underwent typical reactions of carbonyl compounds, such as Wittig olefination. Channeling frustration into productivity: An elusive borane carbaldehyde was liberated from the product of carbon monoxide hydroboration at a frustrated Lewis pair template by treatment with pyridine and isolated as the donor-stabilized adduct (see scheme; Mes=mesityl). In this way, the thermodynamic restrictions of CO insertion into boron-hydrogen bonds could be circumvented. Copyright
