Diphenylphosphinates

The vitamin D3 metabolite la,25-dihydroxycholecalciferol is a lifesaving drug in treatment of defective bone formation due to renal failure. Retrosynthetic analysis (E.G. Baggjolint, 1982) revealed the obvious precursors shown below, a (2-cyclohexylideneethyl)diphenylphosphine oxide (A) and an octahydro-4f/-inden-4-one (B), to be connected in a Wittig-Homer reaction (cf. section 1.5). 

Vinyl acetate reacts with the alkenyl triflate 65 at the /3-carbon to give the 1-acetoxy-1,3-diene 66[68]. However, the reaction of vinyl acetate with 5-iodo-pyrimidine affords 5-vinylpyrimidine with elimination of the acetoxy group[69]. Also stilbene (67) was obtained by the reaction of an excess of vinyl acetate with iodobenzene when interlamellar montmorillonite ethylsilyl-diphenylphosphine (L) palladium chloride was used as an active catalyst[70]. Commonly used PdCl2(Ph3P)2 does not give stilbene. 

Phosphine oxides are prepared similarly[644]. Selective monophosphiny-lation of 2,2 -bis[(lrifluoromethanesulfonyl)oxy]-l,1 -binaphthyl (784) with diphenylphosphine oxide using dppb or dppp as a ligand takes place to give optically active 2-(diarylphosphino)-1,1 -binaphthyl (785). No bis-substitution is observed[645,646]. 

Diphenylphosphinic acid [1707-03-5] M 218.2, m 194-195 , pK 1.72. Recrystd from 95% EtOH and dried under vacuum at room temperature, [see Kosolapoff Organophosphorus Compounds J Wiley, NY, 1950 Kosolapoff and Maier Organic Phosphorus Compounds Wiley-Interscience, NY, 1972-1976.]... 

The initial 2-iodopropyolanilides are rather inaccessible compounds. Their preparation requires a three-stage synthesis with diphenylphosphinic acid azide as the starting material. 

Aryl-5-oxo-1,2,3,5-tetrahydropyrido[ 1,2,3-i/e]quinoxaline-6-carboxy-mides were prepared from 7-chloro derivatives and arylboronic acids in the presence of Na2C03, diphenylphosphinated divinylbenzene-crosslinked polystyrene and Pd(PPh3)4 catalyst. 7-Chloro derivatives were obtained from 7-hydroxy derivatives by heating in POCI3 at 50°C for 3 h (01MIP12). 

Figure 5.2-6 Cationic diphenylphosphine ligands as used in the diphasic, Rh-catalyzed hydro-...

Molybdenum, pentakis(acetonitrile) [methylenebis-(diphenylphosphine)]-structure, 1,77... 

Palladium, ethylenebis(diphenylphosphine)bis-(thiocyanato)-linkage isomers, 1,185... 

Palladium, polymethylenebis(diphenylphosphine)-bis(thiocyanato)-linkage isomers, 1, 185 Palladium, tetraammine-tetrachloropalladate history, 1, 2 Palladium, tetrachloro-crystal structure, 1, 16 Palladium, tris(dinitrogen)-synthesis, 1,28 Palladium complexes a,(5-dione dioximates electrical properties, 6, 143 acetylacetone hydrolysis, 2,379 alkylperoxo... 

Phenylimino)methyl]quinoxalme (186) with dimethyl phosphonate gave 2-[a-amlmo-a-(dimethoxyphosphinyl)methyl]quinoxalme (187) (MeONa, MeOH, reflux, several hours >95%) or with diphenylphosphine oxide gave 2-[a-anilino-a-(diphenylphosphinyl)methyl)quinoxaline (188) (MeONa, EtOH, 0°C, 20 min 95%) several analogs likewise. 

An a-fluorinated phosphinyl sulfoxide derivative, prepared as a mixture of diastereomers by the treatment of lithiated (a-fluoromethyl)diphenylphosphine oxide with menthyl p-toluenesulfinate, has been used for the preparation of enan-tiomerically pure 1-fluorovinyl and 1-fluoromethyl sulfoxides [76]. (E)-Diethyl ferf-butylsulfinylmethylphosphonate 117 has been prepared by the sulfinylation... 

Aqueous HCI solutions hydrolyze the P-N bond to give the amine hydrochloride and R2P-OH, which then disproportionates and is oxidized to diphenylphosphinic acid. A free phosphinous amide anion, with the countercation complexed by a crown ether, has been shown to be hydrolyzed and oxidized to the corresponding phosphinite with unusual ease [119]. Formic acid in toluene can be utilized for converting P,P-disubstituted phosphinous amides into their respective phosphane oxides [30]. 

Arylaluminium compounds (3) are obtained from the reaction of diphenylphosphine and triarylaluminiums. ... 

D. Miscellaneous.—The base-catalysed addition of diphenylphosphine to excess vinyl isocyanide gave (22). However, the reaction of phenyl-... 

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