2946-61-4Relevant academic research and scientific papers
SYN TO ANTI ISOMERIZATION AND DEGRADATION OF PHOSPHINES OF THE 7-PHOSPHANORBORNENE SYSTEM BY ACTION OF METHANOL
Mesch, Keith A.,Quin, Louis D.
, p. 4791 - 4794 (1980)
Syn-Substituted phosphines of the 7-phosphanorbornene system form unstable phosphorane adducts with methanol that either fragment by retro-McCormick cycloaddition or undergo polytopal rearrangement and loss of methanol to give the first example of anti phosphines.
Reactions of Ferrocenium Hexafluorophosphate with P?OR Nucleophiles Give Ring C?H Functionalization or Ring Replacement Products Depending on the Phosphorus Reagent
Chamkin, Aleksandr A.,Krivykh, Vasily V.,Kreindlin, Arkady Z.,Dolgushin, Fedor M.,Ustynyuk, Nikolai A.
, p. 1601 - 1610 (2021/04/16)
Ferrocenium hexafluorophosphate reacts with different P?OR nucleophiles (PR3) in CH2Cl2 at room temperature to give either half-sandwich complexes [CpFe(PR3)3](PF6) (PR3=P(OMe)3, P(OEt)3, PhP(OMe)2) or ferrocenylphosphonium salts [CpFe(C5H4PR3)](PF6) (PR3=iPr2P(OMe), iPr2P(OEt)). Mixtures of both products are formed for some other nucleophiles (PR3=Ph2P(OMe), Ph2P(OEt), PhP(OiPr)2). The mechanism of the former reaction was established using DFT calculations. This reaction pathway is especially characteristic of π-acceptor nucleophiles, which is presumably explained by their ability to stabilize the 19e intermediates. The result of the reaction with tertiary phosphines, aminophosphines, and P?OR nucleophiles can be reliably predicted based on the values of the Tolman electronic parameter (below 2070 cm?1 – only ferrocenylphosphonium salt, in between 2073 cm?1 and 2080 cm?1 – only half-sandwich complex, and in the range from 2070 cm?1 to 2073 cm?1 – mixtures of both products).
Silver-Catalyzed Regioselective Phosphorylation of para-Quinone Methides with P(III)-Nucleophiles
Liu, Yu,Tang, Ke-Wen,Wong, Wai-Yeung,Xie, Jun,Xiong, Biquan,Xu, Shipan,Xu, Weifeng
, p. 14983 - 15003 (2021/11/12)
A simple and efficient method for the silver-catalyzed regioselective phosphorylation of para-quinone methides (p-QMs) with P(III)-nucleophiles (P(OR)3, ArP(OR)2, Ar2P-OR) has been established via Michaelis-Arbuzov-type reaction. A broad range of P(III)-nucleophiles and para-quinone methides are well tolerated under the mild conditions, giving the expected diarylmethyl-substituted organophosphorus compounds with good to excellent yields. Moreover, a series of corresponding enantiomers can be obtained by employing dialkyl arylphosphonite (ArP(OR)2) as substrates. The control experiments and 31P NMR tracking experiments were also performed to gain insights for the plausible reaction mechanism. This protocol may have significant implications for the formation of C(sp3)-P bonds in Michaelis-Arbuzov-type reactions.
Scalable Enantiomeric Separation of Dialkyl-Arylphosphine Oxides Based on Host–Guest Complexation with TADDOL-Derivatives, and their Recovery
Bagi, Péter,Fogassy, Elemér,Herbay, Réka,Holczbauer, Tamás,Keglevich, Gy?rgy,Mátrav?lgyi, Béla,Madarász, János,Székely, Gy?rgy,Varga, Bence
supporting information, (2020/03/23)
Several dialkyl-arylphosphine oxides were prepared, and the enantioseparation of the corresponding racemates was elaborated with host–guest complexation using TADDOL-derivatives. The crystallization conditions were optimized and two separate crystallization methods, one in organic solvent, and the other in water, were found to yield five examples of phosphine oxides with enantiomeric excess values higher than 94 %. A gram scale resolution was performed, and both enantiomers of the methyl-phenyl-propyl-phosphine oxide were separated with (R,R)- or (S,S)-spiro-TADDOL. The intermolecular interactions responsible for the enantiomeric recognition between the chiral host and guest molecules were investigated by single-crystal X-ray diffractional structural determinations. The similarities in the structural patterns of a few diastereomeric crystals were checked by powder X-ray diffraction, as well. Organic solvent nanofiltration (OSN) was used as a scalable technique for the decomposition of the corresponding phosphine oxide–spiro-TADDOL molecular complexes, and for the recovery of the phosphine oxide enantiomers and resolving agents.
Efficient Synthesis of Phosphonamidates through One-Pot Sequential Reactions of Phosphonites with Iodine and Amines
Chen, Xunwei,Luo, Wenjun,Wang, Yanlin,Li, Zikang,Ma, Xiaorui,Peng, Ai-Yun
, p. 14474 - 14480 (2020/10/06)
A one-pot sequential strategy to construct phosphonamidates has been developed by generating phosphonites in situ from arylmagnesium bromides and triethyl phosphite followed by treatment with iodine and amines. A variety of phosphonamidates were obtained with good to excellent yields at room temperature from easily available materials.
Preparation method for catalytically compounding benzyl phosphonate by using basic ionic liquid
-
Paragraph 0037; 0040; 0041, (2018/01/12)
The invention belongs to the technical field of organic synthesis and relates to a preparation method for benzyl phosphonate as a key intermediate of an acyl phosphine oxide type photoinitiator. According to the method, benzene, phosphorus trichloride and alkyl alcohol are taken as main raw materials and are compounded into benzyl phosphonate through two-step reaction. The preparation method is characterized in that a target product is generated through the low-temperature reaction of the dichlorophenyl phosphine and alcohol under the condition of a gemini basic ionic liquid catalyst in the second step reaction, the reaction temperature is controlled within -10 DEG C to 10 DEG C, the dichlorophenyl phosphine is dropwise added and then the mixture reacts for 0.5-7 hours under a stirring condition after the temperature is increased to 30-50 DEG C. The preparation method has the advantages of low cost, simple and convenient after-treatment, high yield, and the like, and is suitable for industrial production.
Direct conversion of phosphonates to phosphine oxides: An improved synthetic route to phosphines including the first synthesis of methyl JohnPhos
Kendall, Alexander J.,Salazar, Chase A.,Martino, Patrick F.,Tyler, David R.
supporting information, p. 6171 - 6178 (2015/02/19)
The synthesis of tertiary phosphine oxides from phosphonates was achieved reliably and in good to excellent yields using stoichiometric amounts of alkyl or aryl Grignard reagents and sodium trifluoromethanesulfonate (NaOTf). In the absence of the NaOTf additive, covalent coordination oligomers of magnesium and phosphorus species dominate the reaction, producing very low yields of phosphine oxide, but high conversions of the phosphonate starting material. Mechanistic studies revealed that a five-coordinate phosphorus species - not a phosphinate - is the reaction intermediate. A diverse array of phosphonates was converted to phosphine oxides using a variety of Grignard reagents for direct carbon-phosphorus functionalization. This new methodology especially simplifies the synthesis of dimethylphosphino (RPMe2)-type phosphines by using air-, water-, and silica-stable intermediates. To highlight this reaction, a new Buchwald-type ligand ([1,1′-biphenyl]-2-yldimethylphosphine, or methyl JohnPhos) and a classic bidentate phosphine, bis(diphenylphosphino)propane (dppp), were synthesized in excellent yields.
Simple unprecedented conversion of phosphine oxides and sulfides to phosphine boranes using sodium borohydride
Rajendran, Kamalraj V.,Gilheany, Declan G.
supporting information; experimental part, p. 817 - 819 (2012/02/03)
A variety of phosphine oxides and sulfides can be efficiently converted directly to the corresponding phosphine boranes using oxalyl chloride followed by sodium borohydride. Optically active P-stereogenic phosphine oxides can be converted stereospecifically to phosphine boranes with inversion of configuration by treatment with Meerwein's salt followed by sodium borohydride.
Enantioselective preparation of P-chiral phosphine oxides
Adams, Harry,Collins, Rebecca C.,Jones, Simon,Warner, Christopher J. A.
supporting information; experimental part, p. 6576 - 6579 (2012/01/15)
A highly efficient chiral auxiliary-based strategy for the asymmetric synthesis of P-chiral phosphine oxides in >98:2 er has been developed. The methodology involves the highly stereoselective formation of P-chiral oxazolidinones that then undergo displacement with a variety of Grignard reagents to prepare the desired phosphine oxides.
Synthesis of P-stereogenic phosphorus compounds. Asymmetric oxidation of phosphines under appel conditions
Bergin, Enda,O'Connor, Cormac T.,Robinson, Shane B.,McGarrigle, Eoghan M.,O'Mahony, Colm P.,Gilheany, Declan G.
, p. 9566 - 9567 (2008/02/13)
Racemic phosphines are converted into enantioenriched phosphine oxides via a synthetically simple, but theoretically interesting, oxidation procedure in good enantiomeric excess (up to 80%) and excellent yields (>95%). These phosphine oxides can be oxidatively coupled to provide easy access to enantiopure DiPAMPO analogues. Particularly attractive aspects of this procedure are the operational simplicity and the low cost required to synthesize these high value compounds. Copyright
