Phosphinothioic acids

Phosphorus acids containing P—S bonds in which the sulfur atom acts as the metal ligating atom also received much attention.243,252,255-261 The commercially available reagents bis(2,4,4-trimethylpentyl)phosphinothioic acid (Cyanex 302) and bis(2,4,4-trimethylpentyl)dithiophosphinic... 

The reaction of carbodiimides with phosphonothioic and phosphinothioic acid as well as phosphonoselenoic and phosphinoselenoic acids " proceed in a similar manner. 

PHOSPHINOTHIOIC ACID, DIPHENYL-, S-(4-CHLORO-2-BUTYNYL) ESTER see CEV840 l,l, T -PHOSPHINOTHIOYUDYNETRISAZIRIDINE... 

The selective cleavage of the 2-methoxy group in (2-methoxyphenyI)(4-methoxyphenyl)phosphinothioic acid by... 

Thiophosphorous acids exist in the tetracoordinated from, except bis(trifluoromethyl)-phosphinothioic acid (43). Two-coordinated thioxophosphines and selenoxophos-phines appear to be kinetically more stable than oxophosphines. They have been generated by pyrolysis (X = S) or photolysis (X = Se) of 44 (equation 117) and the first stable thioxophosphines (equation IIS) " and a moderately stable selenoxophosphine (equation 119) " have recently been isolated. 

Several cyclic systems that contain phosphorus as a ring atom and which, structurally, are cyclic esters of phosphonothioic or phosphinothioic acids, are obtainable through... 

The interaction of a phosphinothioic acid (or a dialkyl phosphorothioic acid) with an alkyl isocyanide yields the corresponding A-alkylthioformamide together with a monothio anhydride (reaction 21) ". A further interesting sequence commences with the interaction of a diarylphosphine oxide, R2P(0)H (R = Ph or p-Tol) with HCNS. It is known that such... 

The cleavage of the anhydride bond in mono- and di-thio anhydrides of phosphonothioic mono esters (and indeed also of similar anhydrides of phosphinothioic acids), with... 

The mono-thio, -seleno and -telluro analogues of phosphonic and phosphinic acids are tautomeric (equations 1, 2 and 4). In the case of the sulphur-containing compounds, an attempt has been made to estimate the equilibrium compositions of a variety of acids by means of physicochemical measurements. The alkali metal salts of phosphonothioate and phosphinothioate acids possess anions which are mesomeric and, theoretically, it is possible for such ions to act as sources of both O-and S-substituted products. The same products can be obtained through reactions between the free acids and diazoalkanes, and because these reactions are relatively fast, it might be expected that the composition of the product mixtures might be a reflection of the tautomer composition of the acids. 

The alkylation, with the more reactive of alkyl halides, of the sodium salts of monoes-terified phosphonothioic acids (equation 22) (see also Scheme 11) or of the disodium salts 107 results in preferential S-alkylation, and the same situation obtains for the salts of phosphinothioic acid " methylation can also be carried out with dimethyl sulphate. Alkylations may also be performed under phase-transfer conditions. From both practical and theoretical perspectives, the subject is more complex, since the course of alkylation reactions depends on the nature of the alkylating agent, on the polarity of solvent and whether this is protic or non-protic and on the concentrations of reactants a study of these features has been the subject of two reports In non-polar or weakly polar aprotic media, or in EtOH, alkylation occurs almost exclusively on sulphur, but in dipolar aprotic solvents, O-alkylation also takes place. The relative yields of sulphur- and oxygen-substituted derivatives, [Qs/Qol depends, for a given solvent, on the nature of substituents on phosphorus, i.e. essentially, whether the substrate is a thiophosphoric, thiophosphonic or thiophosphinic acid. With alkyl tosylates as alkylating agents at 0.02 m in hmpt, the alkylation of sodium 0,0-dialkyl or diphenyl phosphorothioates results in 100% overall conversions with [Qs/Qo] 5 the overall yields for sodium diphenyl- or diisopropyl-phosphinothioates are lower (50-100%) with [Qs/Qo] 1 ... 

Free phosphonothioic and phosphinothioic acids, and their selenium analogues, are readily alkylated by diazoalkanes, diazo esters or diazo ketones. The early work has been... 

Reference has already been made to properties of mixed phosphinic-sulphonic anhydrides. / rr-Butylphenylphosphinothioic trifluoromethanesulphonic anhydride (101) was prepared, in both racemic and optically active forms, from the phosphinothioic acid and trifluoromethanesulphonic anhydride in dichloromethane at -50 °C... 

The effects of changes in structure, temperature, and reaction medium on the kinetics of alkaline hydrolysis of aryl esters of phosphinothioic acids (182 R = R = Me or Ph R = Me, R = Ph X = H, Br, Me, or NO2) have been investigated. The effect of the nature of the leaving group on the kinetics of alkaline hydrolysis of aryl diphenylphosphinates has also been reported on. Indirect evidence has been advanced for the participation of the azaphospholi-dines (183) in the solvolysis of A/-[amino(methyl)phosphinyl]-L-phenylalanine derivatives, and it includes the transfer of the P-amino group to the phenyl-alanyl carbonyl. The products from the hydrolysis or ammonolysis of fosfomycin have the threo structure and have been shown to possess no antibiotic activity. ... 

Complexes of diorganophosphinous acids, R2P(0)H, with tin(iv) chloride have been reported. Co-ordination of the dialkylphosphinic and dialkyl-phosphinothioic acids to tin in the complexes [R R P(0)YH]2,SnX4 (Y = O or S) is effected through the phosphoryl oxygen in both cases. The phosphinic acid complexes lose hydrogen chloride at 120—140 °C to form the compounds [R R P(0)0]2SnCl2, which appear to be chain polymers of the type (18.) ... 

The fully diastereoselective Michael addition of selected sulfur and nitrogen nucleophiles (NuH) to a chiral non-racemic 2-phosphono-2,3-didehydrothiolane S -oxide (466) has been described by Kielbasinski and co-workers (Scheme 118). " The enantiomeric excesses of the obtained adducts (467) could be determined by P NMR spectroscopy using (R)-( + )-t-butyl(phenyl)phosphinothioic acid as a chiral solvating agent. 

Synonyms Diisooctylthiophosphinic acid Phosphinothioic acid, bis (2,4,4-trimethylpentyl)-... 

Phosphinothioic acid, bis (2,4,4-trimethylpentyl)-. See Bis (2,4,4,-trimethylpentyl) thiophosphinic acid Phosphite 1. See Tetrakis (2,4-di-t-butylphenyl)-4,4 -biphenylenediphosphonite Phosphite 2. See Bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite PhosPho 642. See Hydroxylated lecithin PhosPho E-100, PhosPho F-97. See Lecithin PhosPho H-00, PhosPho H-150. See Hydrogenated lecithin... 

The deselenonation of phosphinoselenoic acids by dimethyl sulfoxide (DMSO) (39) proceeds exothermically, whereas the corresponding reaction with phosphinothioic acids requires heating at 100°. The reactivity of the P=X bond is proportional to the softness disparity of the two adjoining atoms. 

Phosphinothionic (thiophosphinic) chlorides can be obtained by reacting phosphorus pentachlo-ride with phosphinothioic acids (9.429), by the action of sulphuryl chloride on diphosphine disulphides (9.430) or by the action of thiophosphoryl chloride on phosphinyl chlorides (9.431). 

Phosphonothious acids may exist in equilibrium with the two phosphinothioic acids. The diesters can be made by reacting alcohols or thiols with an appropriate chlorophosphonite, in the presence of a base to remove hydrogen chloride (9.467, 9.468). A cyclic phosphonothionic ester can be obtained from phosphonic dihalides (9.528). 

Phosphinothioic acids, R2POSH, are obtainable by direct addition of sulphur to a secondary phosphine oxide or phosphinous ester, or by treatment of a diphosphine disulphide with NaOH or thiophosphinic chloride with NaOH followed by mineral acid (Eigure 9.24). 

As in the case of inorganic phosphorothioate ions and salts of the type (RO)2POS M+, there arise three possible formnlae for salts of phosphinothioic acid R2POS" M. It appears from spectroscopic evidence that thiono, thiolo or mesomeric structures may exist in different salts, as weU as arrangements in which the metal atom is covalently bound to either the O or the S atom. The electronegativity of the metal atom and steric effects from the group R are liable to influence this situation. 

Reaction of optically pure 104 with organolithiums to form 105 occurs with preponderant P-0 bond cleavage and retention of configuration (de>90%), exactly like in the modern Juge-Stephan method, but at that time those observations were unexpected. The retention of configuration in the ring opening of 104 was explained by the sequence formation of a pentacoordinated intermediate-pseudorotation-apical elimination. Acidolysis of 105 produced the desired phosphinothioic acids 106 in ee values better than 90%. This step is also directly comparable to the acidic methanolysis in the modern method. 

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