Phosphinic acid chlorides esters

Thus phosphaallenes react with HC1 or methanolate, respectively, adding to the PC double bond and forming the phosphinous acid chloride or the corresponding methyl ester. In these cases the phosphorus atom acts as an electrophilic center. During the turnover of la,c together with H202/H20 the phosphorus atom again is attacked in a nucleophilic way and is oxidized to phosphinic acid 4a,c (Scheme 15). 

In the simplest form of the Abramov reaction, the phosphorus-containing reactant is hypophosphorous acid (phosphinic acid) or an ester thereof, and in the reactions between the acid and formaldehyde or benzaldehyde the initial product is the phosphinic acid 144 (R = H or Ph.). However, the reaction can proceed further to give the bis(l-hydroxyalkyl)phosphinic acid (145 R = H or Ph) the latter (R = Ph) reacts readily with yet more benzaldehyde to give its benzylidene derivative, 5-hydroxy-2,4,6-triphenyl-1,3,5-dioxaphosphorinane 5-oxide (146 R = Ph). When acted on by a second mole of cyclohexanone in the presence of acetyl chloride, (l-hydroxycyclohexyl)phosphinic acid (147) gives the novel phosphinic chloride 148, characterized as the free acid 149 following ready hydrolysis A reaction between a phosphinic acid (150) and a second (non-identical) carbonyl compound leads to an unsymmetrical phosphinic acid (151). Esters of symmetrical 1, r-dihydroxy-substituted phosphinic acids are preparable from hypophosphite esters, H2P(0)0R ". ... 

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 . ... 

Phosphinic add esters from chlorophosphines via phosphinic acid chlorides... 

Conversion of Acids to Acid Chlorides. The reaction of carboxylic acids with triphenylphosphine-CCU reportedly produces acid chlorides in good yield under mild conditions (eq 9). These conditions will allow acid sensitive functional groups to survive. Phosphoric mono- and diesters are successfully converted into the phosphoric monoester dichlorides and diester chlorides, respectively. The reaction of the diethyl ester does not produce the acid chloride. Instead, the anhydride is formed. Phosphinic acid chlorides can also be prepared from the corresponding phosphinic acid under these conditions (eq 10). ... 

In general, if the desired carbon—phosphoms skeleton is available in an oxidi2ed form, reduction with lithium aluminum hydride is a powerful technique for the production of primary and secondary phosphines. The method is appHcable to halophosphines, phosphonic and phosphinic acids as well as thein esters, and acid chlorides. Tertiary and secondary phosphine oxides can be reduced to the phosphines. 

The reaction of dialkyl esters of 1,2-alkadienylphosphonic and phosphinic acids with methyl and phenylsulphenyl chloride, leads exclusively to 2,5-dihydro-l,2-oxaphosphole-2-oxide derivatives [113-115],... 

Chloroform, Chloropicrin, 1,1-Dichloroethylene, Endrin, Hexachlorocyclopentadiene, Methyl chloride. Methylene chloride, Tetrachloroethylene, 1,1,1 -Trichloroethane, Trichloroethylene Phosphine, see Pentachlorobenzene, Phorate Phosphoric acid, see Dichlorvos, Ethephon. Glvphosate. Malathion, Mevinphos, Parathion, Sulfotepp, Tributyl phosphate, Trichlorfon Phosphoric acid, dimethyl ester, see Mevinphos, Oxvdemeton-methvl Phosphorothioic acid, see Parathion Photoaldrin, see Aldrin Photoaldrin chlorohydrin, see Dieldrin Photodieldrin, see Aldrin, Dieldrin Photoheptachlor, see Heptachlor Photoketoaldrin, see Aldrin Phthalaldehyde, see Naphthalene Phthalaldehydes, see Tolnene Phthalic acid, see Anthracene, Benzo[a]anthracene, Benzyl bntyl phthalate, Dichlone. Diethyl phthalate, Dimethyl phthalate, Naphthalene, Naptalam. I ene... 

Branched acids and esters are obtained from the palladium-catalyzed reaction in the absence of phosphines, and in the presence of copper chloride and HC1.79 The mild reaction conditions and the regio-specificity make this a very attractive carboxylation procedure (entry 5, Table 5). Internal straight chain alkenes can be hydrocarboxylated, but the rates are slower and the reaction is not regiospecific. 

The synthesis of dendritic carbosilanes functionalized with various diphenylphosphino carboxylic acid ester endgroups has also been reported by the Van Koten group in collaboration with Vogt et al. [40,41], The coupling of carbosilane supports containing benzylic alcohol moieties with phos-phinoxy carboxylic acid chlorides resulted in the formation of Go and Gi phosphine oxides, which subsequently were converted into the phosphino... 

Tris(trimethylsilyl)phosphine and its more reactive derivative lithium bis-(trimethylsilyl)phosphide-2tetrahydrofuran are very useful reagents for the preparation of compounds with a single or a multiple element phosphorus bond. They react readily with various element halides, with carboxylic acid chlorides, and with carboxylic esters, as well as with other organic electrophiles via a substitution of lithium and/or a cleavage of the weak polar Si-P bonds. 

Trans-tSksaes can be synthesized by the Homer reaction from the ketophosphine oxide, which is reduced selectively to the threo adduct. This inteimediate is typically foimed by reaction of the phosphine oxide widi an ester or acid chloride. Alternatively, the keto intermediate may be obtained by oxidation of -hydroxyphosphine oxides. This sequence was applied to the synthesis of the pure ( )-triene (237) by Warren (equation 57). ... 

In 1978, Bartlett published a study of the reaction of esters and acid chlorides to produce P-keto sulfones (467), which could be converted to the enol phosphinates (468) and reduced with sodium in ammonia to the alkyne (469 Scheme 61). The overall yields for the process are good. As discussed in... 

Moskva, V.V., Maikova, A.L, and Razumov, A.L, Phosphinic and phosphinous acid derivatives. Part 58. Reaction of ortho esters of carboxylic acids and acetals with phosphorus(in) acid chlorides, Zh. Obshch. Khim., 39, 595, 1969 Chem. Abstr, 71, 50076r, 1969. 

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