Metal atom reactions with phosphites

Mnltinnclear Re hydrides, in particnlar CO/phosphine complexes, with the hydride bridging two or three metals and componnds with H atoms bridging Re and other metals, for example, obtained from the reactions of Re polyhydrides with metal salts, have been reported. The coordination chemistry of hydrido/phosphine complexes has been extended, in a nnmber of cases, to related phosphite, phosphonite, or arsine complexes. ... 

Phosphites. Tertiary phosphites are also commonly used and are particularly effective ia most mixed metal stabilizers at a use level of 0.25—1.0 phr. They can take part ia a number of different reactions duting PVC processing they can react with HCl, displace activated chlorine atoms on the polymer, provide antioxidant functionaHty, and coordinate with the metals to alter the Lewis acidity of the chloride salts. Typical examples of phosphites are triphenyl phosphite [101 -02-0], diphenyl decyl phosphite [3287-06-7], tridecyl phosphite [2929-86-4], and polyphosphites made by reaction of PCl with polyols and capping alcohols. The phosphites are often included in commercial stabilizer packages. 

Cyclometalation is one of the most reliable and versatile methods for the synthesis of stable Pd-C a-bonds. In this reaction, a palladium (or other metal) complex is reacted with a ligand possessing a donor atom. The metal is directed by the donor atom to insert into a C-H bond, forming a chelate ring. This donor is usually the nitrogen of a tertiary amine, heterocyclic amine, or imine, or a phosphorus in a tertiary phosphine or phosphite. Other donor atoms, such as O and S, are occasionally encountered. The chelate ring size is normally five. ... 

Other fused thiiranes are more thermally stable. For example, the compound 45 desulfurizes at 160 °C (Scheme 11) <1987JA3801, 1990JA3029>. The reaction provided alkenes with retention of stereochemistry. In the presence of a desulfurizing agent such as phosphines or phosphites, the desulfurization temperature may be decreased to room temperature (Section 1.06.6.6) <1984CHEC(7)131>. The desulfurization of thiiranes is also subjected to transition metal catalysis. Since the initial step involves coordination of the metal to thiirane sulfur atom, the topic is discussed further in Section 1.06.6.4. 

Reduction by Hydrazine. This was a very successful method for preparing the palladium (0) and platinum (0) derivatives with tertiary phosphines, phosphites, and arsines (4, 129, 130, 133). Also, the tetra-isocyanidenickel(O) compounds can be obtained at high yield in this way (132). In the case of platinum this reduction can give place either to zero valent derivatives (130) or to platinum (II) hydrides (49), according to the reaction conditions, the nature of the ligands, and the halogen atoms bound to the metal. This reduction is a very complicated reaction (186) in any case. 

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