984-43-0Relevant articles and documents
2-Phenoxyethyldiphenylphosphine oxide as an equivalent of diphenylvinylphosphine oxide in nucleophilic additions
Bondarenko, Natalia A.,Tcarkova, Kseniia V.,Belus', Svetlana K.,Artyushin, Oleg I.
, p. 902 - 910 (2021/06/25)
A facile method for the synthesis of β-functionalized ethyldiphenylphosphine oxides is developed based on readily available 2-phenoxyethyldiphenylphosphine oxide used as an equivalent of diphenylvinylphosphine oxide in the reactions of addition of different PH- and NH-nucleophiles in DMSO in the presence of KOH. The transformations of labile phosphine oxides of a general formula Ph2P(O)CH2CH2OR, where R = Ph, H, or Ph2P(O)CH = CH2, in aq.KOH/DMSO and solid KOH/DMSO systems are explored in the absence of nucleophilic reagents.
31P NMR spectroscopic analysis on photooxidation of 1,n-bis(diphenylphosphino)alkanes with the aid of DFT calculations
Yasui, Shinro,Yamazaki, Shoko
, (2020/02/15)
The chloroform-d solution of diphosphine, 1,n-bis(diphenylphosphino)alkane (Ph2P(CH2)nPPh2; n = 1-6), was photolyzed with light from a xenon lamp in air. The progress of the reaction was followed by 31P NMR spectroscopy. The observed spectral change showed that the diphosphine is initially oxidized to diphosphine monoxide, Ph2P(═O)(CH2)nPPh2, which is further oxidized to diphosphine dioxide, Ph2P(═O)(CH2)nP(═O)Ph2. The oxidation of the diphosphine to the diphosphine monoxide took place according to first-order kinetics with respect to the concentration of the diphosphine, the first-order rate constant, kobs, being larger with increasing number of the methylene units in the spacer. The observation in kinetics is interpreted based on the conformation of the diphosphine radical cation intermediate initially generated by electron transfer from the photoexcited diphosphine to oxygen. Density functional theory (DFT) calculations predict that the diphosphine radical cation takes “folded” conformation where two phosphorus atoms are arranged closely to each other. The “folded” conformer of the diphosphine radical cation results from electrostatic interaction of these two phosphorus atoms. This conformer explains the observed dependency of kobs on the length of the spacer in the diphosphine.
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.
