55739-58-7Relevant articles and documents
Unraveling the catalytic cycle of tertiary phosphine oxides reduction with hydrosiloxane and Ti(O i Pr)4 through EPR and 29Si NMR spectroscopy
Petit, Christelle,Poli, Evelyne,Favre-Reguillon, Alain,Khrouz, Lhoussain,Denis-Quanquin, Sandrine,Bonneviot, Laurent,Mignani, Gerard,Lemaire, Marc
, p. 1431 - 1438 (2013)
The reduction of tertiary phosphine oxides using tetramethyldisiloxane (TMDS) as a mild reducing agent and catalytic amount of TiIV isopropoxide has been studied in detail. An extensive EPR study has revealed the presence of at least five TiIII species, and structures have been proposed. Thus, a single electron transfer (SET) mechanism consisting of a back and forth oxido-reduction of Ti from the IV to the III oxidation state could be proposed. Reduction of TiIV produces a Si? that undergoes a O2- abstraction from PV compounds leading to PIII compounds and Si-O? species. Reoxidation of TiIII by the latter gives silanol species. This mechanism was further probed by 29Si NMR analysis of the reaction mixture as a function of time and by the reduction of optically active P-stereogenic tertiary phosphine oxides. A practical reduction protocol of Ph3PO with these environmentally benign reagents on a 100 g scale has been developed.
The Trityl-Cation Mediated Phosphine Oxides Reduction
Landais, Yannick,Laye, Claire,Lusseau, Jonathan,Robert, Frédéric
supporting information, p. 3035 - 3043 (2021/05/10)
Reduction of phosphine oxides into the corresponding phosphines using PhSiH3 as a reducing agent and Ph3C+[B(C6F5)4]? as an initiator is described. The process is highly efficient, reducing a broad range of secondary and tertiary alkyl and arylphosphines, bearing various functional groups in generally good yields. The reaction is believed to proceed through the generation of a silyl cation, which reaction with the phosphine oxide provides a phosphonium salt, further reduced by the silane to afford the desired phosphine along with siloxanes. (Figure presented.).
Chemoselective Reduction of Phosphine Oxides by 1,3-Diphenyl-Disiloxane
Buonomo, Joseph A.,Eiden, Carter G.,Aldrich, Courtney C.
supporting information, p. 14434 - 14438 (2017/10/23)
Reduction of phosphine oxides to the corresponding phosphines represents the most straightforward method to prepare these valuable reagents. However, existing methods to reduce phosphine oxides suffer from inadequate chemoselectivity due to the strength of the P=O bond and/or poor atom economy. Herein, we report the discovery of the most powerful chemoselective reductant for this transformation to date, 1,3-diphenyl-disiloxane (DPDS). Additive-free DPDS selectively reduces both secondary and tertiary phosphine oxides with retention of configuration even in the presence of aldehyde, nitro, ester, α,β-unsaturated carbonyls, azocarboxylates, and cyano functional groups. Arrhenius analysis indicates that the activation barrier for reduction by DPDS is significantly lower than any previously calculated silane reduction system. Inclusion of a catalytic Br?nsted acid further reduced the activation barrier and led to the first silane-mediated reduction of acyclic phosphine oxides at room temperature.
