Miscellaneous Decomposition Reactions

These postulates were supported by a DFT study carried out by Cavallo and co-workers. 

Rourke and co-workers showed that the reaction of a simple A-aryl imi-dazolium ion with [Pd(OAc)2] in DMSO led to a Pd-carbene complex, but the presence of an aniline ligand derived from the initial imidazolium salt in the coordination sphere of the Pd implied the presence of a significant decomposition process.  

In 2007, Nolan and co-workers presented a reaction in which a Pt-coordi-nated olefin was attacked by exogenous free carbene. Considering that binding of an olefin to metals such as Pt dramatically increased their electro-philicity, it is surprising this type of reaction has not been more commonly observed in the attempted preparation of carbene complexes from this class of precursors. 

It is readily apparent that C-H insertion (orthometalation), reductive elimination, and displacement by ancillary ligands are some of the main pathways for decomposition of NHC ligands. In this Section, we will address ligand design elements that can be employed to minimize or eliminate such decomposition reactions. 

---

C. Miscellaneous.—Treatment of the phosphonium bromide (114) with one equivalent of butyl-lithium gave triphenylphosphine and benzylidene-methylamine via a Hofmann-like decomposition, whereas reaction with two equivalents of butyl-lithium resulted in the production of butyltriphenyl-phosphonium bromide. ... 

Elsewhere in the text, a number of incidents have involved evolution of gas(es) arising from slow decomposition or hydrolysis in storage, progressive thermal decomposition, or from other miscellaneous reactions or processing faults. Individual incidents may be found under ... 

Interesting methods have been developed for the synthesis of organophos-phazenes [23]. These are summarized in Scheme 2. For example, the JV-silyl-P-halo or alkoxyphosphoranimines upon decomposition afford or-ganocyclophosphazenes [24]. Other miscellaneous reactions employed for the synthesis of organocyclophosphazenes are enumerated in Eqs. (7-11). 

Mildness and Miscellaneous Reactions. The mildness of the lipases has been particularly well suited in transformations involving labile compounds that are likely to undergo decomposition when conventional chemical methods are applied, such as the long-chain polyunsaturated to-3-type fatty acids and highly labile prostaglandin precursor derivatives. Under mild conditions, lipase was exploited to hydrolyze the peracetal protected hydroperoxy derivative in eq 18 to afford the corresponding acid without affecting the peracetal protection moiety. ... 

Pyrolysis under vacuum of aspen poplar wood chips exhibited an active zone of decomposition occurring between 240 and 300 C . A 58 % by wt, yield of pyrolytic oil was obtained at 350°C which contained miscellaneous compounds such as phenols, carboxylic acids, alcohols and esters. The vacuum process removes the reaction products before they are further decomposed. The yield of relatively volatile phenols (monolignols in this paper) depends on the pyrolysis materials. The yield of phenols varied from 1 to 3.7 % when different biomass samples were subjected to vacuum pyrolysis. ... 

In the following three sections we shall discuss four applications of quantum mechanics to miscellaneous problems, selected from the very large number of applications which have been made. These are the van der Waals attraction between molecules (Sec. 47), the symmetry properties of molecular wave functions (Sec. 48), statistical quantum mechanics, including the theory of the dielectric constant of a diatomic dipole gas (Sec. 49), and the energy of activation of chemical reactions (Sec. 50). With reluctance we omit mention of many other important applications, such as to the theories of the radioactive decomposition of nuclei, the structure of metals, the diffraction of electrons by gas molecules and crystals, electrode reactions in electrolysis, and heterogeneous catalysis. 

The different applications have been classified by reaction type oxidation (sect. 2.1-2.3), hydrogenation (sect. 2.4), environmental (sect. 2.5) and miscellaneous (sect. 2.6). The environmental applications have been grouped together in view of the present relevance of this field. It includes total oxidation of organic compounds and CO, redox processes such as CO+NO reaction and NO/N2O decomposition. 

---