Phosphinic acid chlorides derivatives

The heterocyclic acylphosphines (52) and (53) have been prepared by the reaction of phenylbis(trimethylsilyl)phosphine with the acid chlorides derived from phthalic and diphenic acids. The reaction of 2,3-dichloromaleic anhydride or thioanhydride with phenylbis(trimethylsilyl)phosphine gives derivatives of the 1,4-dihydro-p-diphosphorin system (54).45... 

Acid chloride derivatives of phosphinous acids [R2POH] and phosphonous acids [RP(OH)2] have been mentioned previously (see Section 3.2) as precursors in the preparation of phosphines. In addition to the coimnon routes of preparation for these trivalent phosphoms acids, particularly through the use of organometallic reagents and Friedel Crafts reactions as noted, several other routes have been developed for their syntheses that are worthy of note. 

For example, two reports of preparation of such species from elemental (red) phosphorus have been noted. The direct preparation of 1-hydroxyphosphonous acids, albeit in moderate yield, is accomphshed by the treatment of elemental phosphorus with aldehydes in aqueous basic medium (equation 12). Using polar aprotic solvents, the double direct addition of elemental phosphoms to arylalkenes proceeds to form phosphinous acids in better yields. Further, acid chloride derivatives are available also by the controlled reaction of elemental phosphoms with chloroalkanes. ... 

Additional phosphonic acid is derived from by-product streams. In the manufacture of acid chlorides from carboxyUc acids and PCl, phosphonic acid or pyrophosphonic acid is produced, frequentiy with copious quantities of yellow polymeric LOOP. Such mixtures slowly evolve phosphine, particularly on heating, and formerly were a disposal problem. However, purification of this cmde mixture affords commercial phosphonic acid. By-product acid is also derived from the precipitate of calcium salts in the manufacture of phosphinic acid. As a consequence of the treatments of the salt with sulfuric acid, carbonate is Hberated as CO2 and phosphonic acid goes into solution. 

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],... 

Diacylphosphines may be prepared by treatment of bis(trimethylsilyl)phenyl-phosphine (65) with acid chlorides.60 A diphosphine derivative (66) is formed with benzoyl chloride.60 A series of complex reactions occurs between nitrobenzenes and diphenyl(trimethylsilyl)phosphine (67).61 The oxides noted below were the only isolable products, and the yields were not high.61... 

Reactions of Phosphonic and Phosphinic Acid Derivatives.—The reactions of phos-phonic and thiophosphonic amides and chlorides with carboxylic acid chlorides and amides have been discussed.101 Dialkyl alkylphosphonates and alkyl dialkylphos-phinates may be used for the iV-alkylation of imidazoles, triazoles, and pyrroles.105... 

Methylisoxazole-5-carboxylic acid was converted into the corresponding 5-carboxamides and 5-(l/7-pyrazol-l-ylcarbonyl) derivatives in satisfactory yields by treatment with thionyl chloride and amines or pyrazoles <2002SC425>. A three-component assembly of isoxazole-5-carboxylic acid chloride, 1,1-dimethylallene, and bis-pinacolatodiboron, catalyzed by a phosphine-free palladium complex, gave 2-acylallylboronate derivatives regiose-lectively (Equation 47) <2003JA12576>. On the other hand, a mild procedure allowed the preparation of /3,7-unsaturated ketones by simple reaction of 3-aryl-5-methylisoxazole-4-carboxylic acid chlorides with allyl bromide and indium in DMF (Equation 48) <1997TL8745>. 

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. 

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. 

Uses of Phosphonic and Phosphinic Acid Derivatives -Analogues of Lawesson s reagent have been employed in the preparation of thiopeptides and the diphenylphosphinothioyl group protects tryptophane during peptide synthesis.Diphenylphosphinic chloride assists in the formation of 3-lactams from 249... 

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