Alkylphosphine oxides

Phosphorus containing poly(maleimide-amines) were synthesized from N,N -bisdichloromaleimido-3,3 -diphenyl alkylphosphine oxides and aromatic diamines or piperazine [144]. The polymers prepared from piperazine are soluble in DMF, DM AC, DMSO, etc., but have poor thermal stability and flame retardancy. 

Similar additions also occurred on vinylphosphine oxides. When the optically active vinylphosphine oxide was used, P-chiral alkylphosphine oxide was obtained with retention of the configuration (Eq. 10.27)60... 

X-Ray data have been published for A -phospholen 1-oxide (65),69 tri-o-tolyl-phosphine derivatives (66),60 and various halogeno-alkylphosphine oxides.61... 

In separate experiments, we have demonstrated that TPO also promotes hydrogenolysis by Ru ( 7), although the effects are weaker than for the Rh-catalyzed hydrocarbonylation of esters. The use of alkylphosphine oxides and their role in Ru-catalyzed syngas reactions have also been reported by Warren and Dombek (8b). 

In the alkylphosphine oxide (and sulphide) the lone pair of electrons on the phosphorus atom completes the octet of the oxygen (or sulphur), as in the case of amine oxides —... 

Alkylation chemistry has also been reported for alkylphosphine oxides and dialkyl phosphonates. The phosphonate carbanions are often preferred as they offer many advantages over the phosphonium ylides. In particular, the phosphonate group is highly acidifying and the resulting organolithium can be smoothly alkylated. 

The a-diazo-jS-keto-alkylphosphine oxides (38) and (39) undergo different fragmentation reactions as shown. For the oxide (38), the predominant reaction involves acyl cleavage, Le. the C—C=0 bond breaks, whereas the oxide (39) displays cleavage... 

The reactions proceed with retention of configuration at phosphorus. Various classical routes to alkylphosphine oxides have been applied in the synthesis of a range of potentially chelating and pincer-like ligands, e.g., (233), the binaphthyl system (234), the hybrid phosphine oxide-N-oxide (235), and the chiral pyridine bis(phosphine oxide) (236). A route to diarylmethylphosphine oxides is afforded by the palladium-catalysed reaction of aryl bromides with tet-rakis(hydroxymethyl)phosphonium chloride in the presence of a base. The diastereoisomeric system (237) has been isolated from the reaction of a cyclic... 

P0lyamid6S. Bis(carboxyethyl)alkylphosphine oxide units can be introduced into the backbone of nylon-6,6 to impart flame retardancy with minimal sacrifice of physical properties. (174). Despite much effort on this approach, these products failed to reach commercialization probably for cost reasons. Small amounts of bis(carboxyethyl)phosphinic acid salts can be introduced into the chain of polyamide-6,6 to impart inherent flame retardancy and stain resistance to carpet fiber (175). 

Enynylphosphine oxides were prepared and then subjected to carbocu-pration reactions to give dienylphosphine oxides, as shown in Scheme 29 Arylhydrazono-alkylphosphine oxides were converted to the corresponding azoalkene derivatives on treatment with iodic acid (Scheme 30). Otherwise unreactive chloroarylphosphine oxides have been shown to undergo Suzuki coupling on MW irradiation in the presence of a highly active palladium-catalyst (Scheme 31 Treatment of 2-fluoro-5-nitrobenzyl bromide with active methylene compounds, such as a p-keto phosphine oxide under suitable conditions led to 4/7-1-benzopyrans (Scheme 32)." ... 

SCHEME 4.22 Copper-catalyzed synthesis of alkylphosphine oxides in water [65]. 

Need to generate an alkylphosphine oxide from an alkene... 

Are there decarboxylative approaches to the synthesis of alkylphosphine oxides that start from propiolic acids ... 

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