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Diphenylphosphinous acid ester

R,5R,6R)-Spiro[4.4]nonane-1,6-diy 1 Diphenylphosphinous acid Ester (R-SpirOP), 504... [Pg.552]

Isomerization of cis- to traos lefins. Sgoutas and ICummerow reported in 1969 that c i-unsaluraled fatly acid esters are isomerized to tro/is-eslers when heated at 65° in a sealed vial with thiols or diphenylphosphine in the presence of azobisisobutyronitrile. The equilibrium mixture contains 75-80% lran.i double bonds. There is no migration of the double bonds. Presumably addition of thiyi or phosphinyl radicals to the double bond is involved. [Pg.505]

Studies on the alkaline hydrolysis of various phosphonic and phosphinic esters have provided information on the electronic or steric effects of substituents and the effects of changes in reaction conditions amongst the substrates so extensively examined are the O-aryl esters of dimethylphosphinothioic acid (552) esters of diphenylphosphinic acid and O-aryfand S -aryf esters of diphenylphosphinothioic acid (553 Z, Y = O or S). Other studies have concentrated on aryl esters of diaryIphosphinic acids (554) , and the effects of the stepwise replacement of P-Me by P-Ph in esters of dimethyl-, methylphenyl- and diphenyl-phosphinic acids The esters 555 (R = EtO, R = Me or Ph, R = R = Ph X = SEt or hydrolyse under alkaline conditions faster than do the comparable 5 -(4-substituted-butyl) esters. Comparable steric and electronic influences on the hydrolyses of phosphonic and phosphinic fluorides phosphinic chlo-rides the phosphonothioic chlorides 556 and other phosphonic and phosphinic esters have been noted. Phosphonic and phosphinic halides are prone to undergo halo-gen-exchange reactions, a process which, in general, is faster for derivatives of phosphonic than for those of phosphonothioic and phosphonoselenoic acids, and to be particularly important for acid fluorides . ... [Pg.606]

Diphenylphosphinic mixed anhydrides have been utilized to form peptide bonds. Peptides are easier to isolate by this method than by employing 1,3-Dicyclohexylcarbodiimide. These anhydrides are the method of choice for the formation of amides of 2-alkenoic acids (eq 1 ). Carbodiimide and acyl carbonate methods proved to be inferior. Primary amines result in better yields than secondary amines. This activation protocol can be employed to form thiol esters (eq 2) p-Amino acids are readily converted to p-lactams with chlorodiphenylphosphine oxide (eq 3). Secondary amines work best. This activation protocol has been utilized to convert acids to amines via a Curtius rearrangement. Phenols have been generated from diene acids, presumably via base-induced elimination of diphenylphosphinic acid from the mixed anhydrides to form ketenes which spontaneously cyclize. Acids have been converted to ketones via activation followed by reaction with organometallic reagents (eq 4)."... [Pg.167]

In the multi-step total synthesis of Herboxidiene methyl ester, one step involved an Arhuzov reaction of an allyl bromide with the ethyl ester of diphenylphosphinous acid (Scheme 6)7... [Pg.53]

The application of / -(diphenylphosphinyl)benzenesulphonic acid (58) to the synthesis of esters of amino-acids has made the work-up much simpler, since the resultant oxide is water-soluble. Diphenylphosphinyl isocyanate (59) can be prepared from diphenylphosphinic amide. [Pg.67]

R)-(-)-Methyl 3-hydroxybutanoate Butyric acid, 3-hydroxy-, methyl ester, D-(-)-(8) Butanoic acid, 3-hydroxy- methyl ester, (R)- (9) (3976-69-0) [(R)-2,2 -Bls(dlphenylphosphino)-1,1 -binaphthyl]dichlororuthenium Ruthenium, [[1,1 -binaphthalene]-2,2 -diylbis(diphenylphosphine)-P,P ]dichloro- (12) (115245-70-0)... [Pg.143]

Another reaction performed in the dead-end reactor discussed before, is the allylic amination of 3-phenyl-2-propenyl-carbonic acid methyl ester with morpholine. [30] First and second generation commercially available DAB-dendrimers were functionalized with diphenylphosphine groups (Figure 4.13). Two different membranes were used, the Nadir UF-PA-5 (ultrafiltration) and the Koch MPF-50 (former SELRO) (nanofiltration), which gave retentions of 99.2% and 99.9% respectively for the second generation functionalized dendrimers. [Pg.83]

Asymmetric hydrogenation has been achieved with dissolved Wilkinson type catalysts (A.J. Birch, 1976 D. Valentine, Jr., 1978 H.B. Kagan, 1978). The (R)- and (S)-[l,l -binaph-thalene]-2,2 -diylbis[diphenylphosphine] (= binap ) complexes of ruthenium (A. Miyashita, 1980) and rhodium (A. Miyashita, 1984 R. Noyori, 1987) have been prepared as pure atrop-isomers and used for the stereoselective Noyori hydrogenation of a-(acylamino) acrylic acids and, more significantly, /3-keto carboxylic esters. In the latter reaction enantiomeric excesses of more than 99% are often achieved (see also M. Nakatsuka, 1990, p. 5586). [Pg.102]


See other pages where Diphenylphosphinous acid ester is mentioned: [Pg.504]    [Pg.504]    [Pg.505]    [Pg.506]    [Pg.532]    [Pg.536]    [Pg.537]    [Pg.504]    [Pg.504]    [Pg.505]    [Pg.506]    [Pg.532]    [Pg.536]    [Pg.537]    [Pg.443]    [Pg.14]    [Pg.36]    [Pg.41]    [Pg.100]    [Pg.609]    [Pg.614]    [Pg.8]    [Pg.116]    [Pg.479]    [Pg.51]    [Pg.52]    [Pg.40]    [Pg.286]    [Pg.13]    [Pg.288]    [Pg.126]    [Pg.75]    [Pg.414]    [Pg.529]    [Pg.3502]    [Pg.24]    [Pg.237]    [Pg.10]    [Pg.28]   
See also in sourсe #XX -- [ Pg.504 ]




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Diphenylphosphine

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