Phosphines synthesis

Nickel, dibromobis[tris(3-aminopropyl)phosphine]-synthesis, 1, 27... 

Some particularly useful specific methods will also be outlined. For further information on phosphine synthesis, the reader is directed to other books and reviews.3-8... 

These nucleophilic reagents react with most common electrophiles such as organohalides, tosylates, aldehydes, ketones, epoxides, and activated alkenes. It should be noted that many workers have found much higher yields if the phosphides are protected as phosphine oxide or borane anions (see Section 3). Phosphide reagents also react with activated arenes to give mixed aryl phosphines (Protocol 2). Metal phosphides therefore provide an alternative, complementary tertiary phosphine synthesis to the electrophilic routes outlined in Section 2.1. 

Recent developments in phosphine synthesis have allowed for catalysis to be carried out in nontraditional media, such as aqueous and fluorous solvents, as well as in supercritical carbon dioxide. Horvath and Gladysz have... 

However, a very common strategy in phosphine synthesis continues to be a final stage reduction of phosphine oxides with silane reagents, of which trichlorosilane is the most popular. Among a considerable range of new monophosphines obtained by trichlorosilane reduction, usually in the final step of the synthesis, are the phosphorus core conjugated triaryl-dendrimer unit... 

Several reports have appeared of the application of unusual organometallic reagents in phosphine synthesis. Treatment of 2-lithiopyridine with anhydrous zinc chloride results in the formation of a 2-pyridylzinc reagent which can be used to introduce the 2-pyridyl group at phosphorus in a controlled manner. Thus, e.g., in its reaction with phenyldichlorophosphine, the 2-pyridyl-(phenyl)chlorophosphine (15) is formed. This has then been converted via the phosphide route into a new class of binucleating ligands (16). The sterically crowded dichlorophosphine (17) (accessible from the reaction of phosphorus trichloride with lithium diphenyl(2-pyridyl)methanide) is converted into the thermally stable phosphirane (18) on treatment with calcium, strontium or barium cyclooctatetraenide.The reaction of phenyldichlorophosphine with the readily accessible titanacycle (19) affords a convenient route to the phosphetene (20). ... 

While lithiophosphide reagents dominate this area of phosphine synthesis, applications of sodio- and potassio-phosphide reagents continue to appear. The... 

Preparation of Phosphines by Reduction. - The reduction of phosphine oxides in the final stage of phosphine synthesis remains a common strategy, with silane reagents often being used. Trichlorosilane has found application in the synthesis of the axially chiral systems (83), 73 (84), 7 (85), 75 the chiral... 

Scheme 47 Pd-catalyzed intramolecular asymmetric phosphination synthesis of benzophospholanes...

A few papers have reported the use of various aluminium-based reducing agents in phosphine synthesis. Lithium aluminium hydride reduction of phosphine oxide precursors provides a route to new 2-phosphinomethyl-1/7-pyrroles and diisobutylaluminium hydride (DIBAL) has been found to be an excellent reagent for the reduction of phosphinites, phosphinates and chlorophosphines. 2-Chloroethylphosphine (CICH2CH2PH2) has been prepared for the first time by a chemoselective reduction of diethyl 2-chloroethylphosphonate with dichloroalane (HAICI2), prepared in situ from LiAlH4 and AlCls. A patent has described the use of metallic aluminium... 

E = As, Sb or Bi) react similarly with Grignard reagents, providing routes to cyclic arsines, stibines and bismuthines. Leung s group has reported further applications of asymmetric Diels-Alder cyclisation reactions in phosphine synthesis. A platinum complex chiral auxiliary has been used to promote the asymmetric [4-1-2] Diels-Alder addition of diphenyl(vinyl)-phosphine to 3-diphenylphosphinofuran, giving the eradocycloadduct (70) as the predominant stereoisomer. Related cycloadditions between 3,4-dimethyl-1 -phenylphosphole and ester-functionalised allylic phosphines have provided chemoselective routes to optically-pure P-chiral 1,2- and... 

Anderson BJ, Glueck DS, DiPasquale AG, Rheingold AL (2008) Substrate and catalyst screening in platinum-catalyzed asymmetric alkylation of bis(secondary) phosphines. Synthesis of an enantiomerically pure C2-symmetric diphosphine. Organometallics 27 4992-5001... 

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