Phosphite complexes hydrolysis reactions

The few Co " phosphite complexes that have been prepared (Table 41) have resulted from disproportionation reactions (equations 114, 115 and 116). Phosphite ester hydrolysis has been found to occur with frans-[Co(DMGH)2(Cl) P(OMe) Ph3 ] (n = 3,2,1) with the formation of the corresponding phosphonato complex anion /ra -tCo(DMGH)2Cl P(0)(OMe) jPh3 ]". This most interesting reaction requires the presence of a nucleophilic agent such as halide (or a nitrogen... 

We wish to report several metal complexes formed from a phosphorous acid diester of the type OP (H) (OR) 2 which underwent isomerization to form a metal-phosphorus bond as in (a). In the course of our investigations on the complexing properties of polycylic phosphites (9 17) j it was found that 2,8,9-trioxa-l-phosphaadamantane (L) undergoes a rapid, acid hydrolysis in acetone to form two colorless, crystalline hydrolysates, A and B. Only isomer A or L complexed with divalent hydrated metal ions, and it is concluded from infrared evidence that A has isomerized as shown in the following reaction sequence. Supporting infrared and PNMR evidence is presented for the tentatively postulated structures of A and B. 

Treatment of the molybdenum alkylidyne complex 191 with 300 atm CO affords a mixture of three products the products of substitution of one and two phosphite ligands and complex 192 [Eq. (154)] (91). The methox-ycarbonyl group in 192 may have arisen from the reaction of an intermediate ketenyl ligand with methanol (derived from hydrolysis of trimethyl-phosphite). Reaction of the compounds 193 with xylylisocyanide was shown to give complexes 194 [Eq. (155)] (91). The products contain the... 

Some insight into the mechanisms of the iodine-promoted carbonylation has been obtained by radioactive tracer techniques [17] and low-temperature NMR spectroscopy [18]. The mechanism involves the formation of HI, which in a series of reactions forms with rhodium a hydrido iodo complex which reacts with ethylene to give an ethyl complex. Carbonylation and reductive elimination yield propionic acid iodide. The acid itself is then obtained after hydrolysis. The rate of carboxylation was reported to be accelerated by the addition of minor amounts of iron, cobalt, or manganese iodide [19]. The rhodium catalyst can be stabilized by triphenyl phosphite [20]. However, it is doubtful whether the ligand itself would meet the requirements of an industrial-scale process. 

Substitution of CO by phosphines 145 The Dotz reaction 149 Rearrangement reactions with loss of CO 151 Photochemical reactions 153 Reactions at the carbene carbon 158 General features 158 Amine nucleophiles 159 Phospine and phosphite nucleophiles 167 Alcohols and alkoxide ion nucleophiles 171 Thiol and thiolate ion nucleophiles 179 Intramolecular nucleophilic reactions 191 Hydroxide ion and water as nucleophiles 194 Insertion reactions initiated by nucleophilic attack Acid-base reactions at the a-carbon 207 General features and methods 207 Kinetic and thermodynamic acidities 209 Effect of structure on pKa values 210 Intrinsic rate constants for proton transfer 219 Thermodynamic acidities in organic solvents 223 Hydrolysis of ionizable carbene complexes 228 Acknowledgments 232 References 233... 

Organic phosphorous(III) compounds are very effective hydroperoxide decomposers. They react stoichiometrically with hydroperoxides, oxidizing the phosphite to phosphate. Sterically hindered aromatic phosphites can also react as chain scission antioxidants. Since phosphites and phosphonites are sensitive to hydrolysis, hydrolysis resistant derivates have to be used. Their contribution to long-term stabilization is small, because they do not react directly with oxygen. In addition to the reaction of phosphites with peroxides and oxygen radicals, positive effects are also described due to complexing with catalytic metal residues. 

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