Protonolysis metal alkoxides

Propionohydroxamic acid metal complexes, 506 Propylenediamine metal complexes, 34 Protactinium complexes cupferron, 510 Proteins electron transfer active sites, 525 metal complexes, 759-774 binding sites, 769,771 naturally occurring, 974 occurrence, 962 Proton exchange amine ligands, 24 Protonolysis metal alkoxides, 352 Prussian blue, 7, 8 Pseudocubanes structure... 

Mechanisms, exemplified by alcohol as donor (493, 496), usually invoke coordination of the substrate (olefins, saturated and unsaturated ketones, and aldehydes), then coordination of the alcohol and formation of a metal alkoxide, followed by /8-hydrogen transfer from the alkoxide and release of product via protonolysis ... 

Protonolysis reactions of alkoxides and aryloxides are common one example is hydrolysis of the metal alkoxide, giving metal oxide with elimination of the alcohol. Although the aim is often to avoid such a reaction, it is of great interest in the deposition of high-purity metal oxides, which are used in areas such as optoelectronics, high f superconductors, and advanced ceramics. ... 

Allylic alcohols are isomerized via direct interaction of the ruthenium atom with alcohol. /3-Elimination of ruthenium hydride from metal alkoxide yields a ruthe-nium-enone species C which undergoes insertion of the olefinic moiety into the Ru-H to form an oxyallylic intermediate D. As a result, the hydrogen atom shifts from the a- to y-position of the allylalcohol. Protonolysis of the oxyallylic species leads to a saturated carbonyl compound and cationic unsaturated species, [CpRu(PPh3)2] A. 

Several common synthetic strategies for the formation of transition metal-heteroatom bonds can be used for the preparation of early transition metal alkoxides, as shown in Equation 4.57. These methods include (1) metathesis between metal halides and alkali metal salts of the corresponding alcohols (2) direct reaction of the alcohols with metal halides in the presence of a base and (3) protonolysis of metal alkyls, amides, or alkoxides with more acidic alcohols. 

Protonolysis of metal alkyls, amides, or alkoxides with more acidic alcohols has also been used to generate alkoxides. Yamamoto has reported the preparation of a series of Ni(ll) and Pd(Il) aryloxides by alcoholysis of the corresponding metal-methyl complexes to release methane (Equation 4.69). Metal-sdylamido complexes are also useful precursors to late metal alkoxides, presumably due to release of steric congestion. ... 

Alkoxide and aryloxide ligands are excellent ligands for the actinides. As a result, these ligands have been studied extensively in the coordination chemistry and reactivity of tri-, tetra-, penta-, and hexavalent actinides. The alkoxides and aryloxides can be synthesized by a variety of routes the two most popular routes include direct reaction of actinide halides with alkali metal salts of the alkoxide or aryloxide of interest and protonolysis of actinide amides by alcohols. 

---