Carbonyl sulfide reactivity

Hydroxy-THISs react with electron-deficient alkynes to give nonisol-able adducts that extrude carbonyl sulfide, affording pyrroles (23). Compound 16 (X = 0) seems particularly reactive (Scheme 16) (25). The cycloaddition to benzyne yields isoindoles in low- yield. Further cyclo-addition between isoindole and benzyne leads to an iminoanthracene as the main product (Scheme 17). The cycloadducts derived from electron-deficient alkenes are stable (23, 25) unless highly strained. Thus the two adducts, 18a (R = H, R = COOMe) and 18b (R = COOMe, R = H), formed from 7, both extrude furan and COS under the reaction conditions producing the pyrroles (19. R = H or COOMe) (Scheme 18). Similarly, the cycloadduct formed between 16 (X = 0) and dimethylfumarate... 

The meso-ionic l,3-dithiol-4-ones (134) participate - in 1,3-dipolar cycloaddition reactions giving adducts of the general type 136. They show a remarkable degree of reactivity toward simple alkenes including tetramethylethylene, cyclopentene, norbomene, and norbor-nadiene as well as toward the more reactive 1,3-dipolarophilic olefins dimethyl maleate, dimethyl fumarate, methyl cinnamate, diben-zoylethylene, A -phenylmaleimide, and acenaphthylene. Alkynes such as dimethyl acetylenedicarboxylate also add to meso-ionic 1,3-dithiol-4-ones (134), but the intermediate cycloadducts are not isolable they eliminate carbonyl sulfide and yield thiophenes (137) directly. - ... 

In this review we have attempted to cover the very recent literature relevant to the coordination chemistry of carbon dioxide and its use as a source of chemical carbon. We have omitted similar investigations involving the more reactive substrates, carbon disulfide and carbonyl sulfide. The reader is referred to a recent review by Ibers (722) which has contrasted the behavior of these sulfides to carbon dioxide. Likewise we have, as stated at the onset, elected to neglect heterogeneous processes involving the reduction... 

A third kind of reactivity is related to the silyl substitution mechanism in that it involves an intermediate N-Si bond cleavage. Insertion of heterocumulenes such as CO2 is common for N-M bonds [7], including the -NSiR3 function in 1 or other molecules [8, 9]. We now report the result of the reaction between 1 and the unsymmetrical carbonyl sulfide, 0=C=S. 

Carbonyl sulfide may be regulated as a D003 hazardous waste under the Resource Conservation and Recovery Act when a solid waste containing this sulfide compound exhibits the characteristic of reactivity as stipulated in Title 40 of the Code of Federal Regulations, Section 261.23. 

Sulfur cycling is affected in a variety of ways, including UV photoinhibition of organisms such as bacterioplankton and zooplankton that affect sources and sinks of DMS and UV-initiated CDOM-sensitized photoreactions that oxidize DMS and produce carbonyl sulfide. Metal cycling also interacts in many ways with UVR via direct photoreactions of dissolved complexes and of metal oxides and indirect reactions that are mediated by photochemically-produced ROS. Photoreactions can affect the biological availability of essential trace nutrients such as iron and manganese, transforming the metals from complexes that are not readily assimilated into free metal ions or metal hydroxides that are available. Such photoreactions can enhance the toxicity of metals such as copper and can initiate metal redox reactions that transform non-reactive ROS such as superoxide into potent oxidants such as hydroxyl radicals. 

Carbonyl sulfide is the most abundant sulfur gas in the global background atmosphere because of its low reactivity in the troposphere and its correspondingly long residence time. It is the only sulfur compound that survives to enter the stratosphere. (An exception is the direct injection of S02 into the stratosphere in volcanic eruptions.) In fact, the input of OCS into the stratosphere is considered to be responsible for the maintenance of the normal stratospheric sulfate aerosol layer. 

CONTEXT Carbonyl sulfide, OCS, is a polar molecule found in petroleum deposits. It is a gas under typical conditions and an irritant because it binds readily to water, where it may eventually react to form CO2 and the toxic and reactive H2S. The strong binding of OCS to water, compared to other gases with similar boiling points (such as propane), arises partly from its being a polar compound, allowing a favorable dipole-dipole interaction with water. 

Pandey KK (1995) Reactivities of carbonyl sulfide (COS), carbon disulfide (CS2) and carbon dioxide (CO2) with transition metal complexes. Coord Chem Rev 140 37-114... 

This section covers the removal of COS, CS2, and light mercaptans from gas streams by amine solutions. These are the principal organic sulfur compounds normally encountered in fuel and synthesis gases. The removal of organic sulfur compounds from liquid hydrocarbons is discussed in the next section. The presence of the above components (and many other reactive species) in a gas to be treated raises two questions (1) How much, if any, of the material will be removed during the treating operation and (2) will the impurities cause deterioration of the amine solution The question of solution deterioration by reaction with various gas impurities is discussed in detail in Chapter 3 this discussion is concerned primarily with removal of carbonyl sulfide, carbon disulfide, and mercaptans from the gas by amine solutions. 

Figure 305. Insertion of carbonyl sulfide into a dithiocarbamate ligand and subsequent reactivity of the expanded-ligand complex.

It is well known that aziridination with allylic ylides is difficult, due to the low reactivity of imines - relative to carbonyl compounds - towards ylide attack, although imines do react with highly reactive sulfur ylides such as Me2S+-CH2-. Dai and coworkers found aziridination with allylic ylides to be possible when the activated imines 22 were treated with allylic sulfonium salts 23 under phase-transfer conditions (Scheme 2.8) [15]. Although the stereoselectivities of the reaction were low, this was the first example of efficient preparation of vinylaziridines by an ylide route. Similar results were obtained with use of arsonium or telluronium salts [16]. The stereoselectivity of aziridination was improved by use of imines activated by a phosphinoyl group [17]. The same group also reported a catalytic sulfonium ylide-mediated aziridination to produce (2-phenylvinyl)aziridines, by treatment of arylsulfonylimines with cinnamyl bromide in the presence of solid K2C03 and catalytic dimethyl sulfide in MeCN [18]. Recently, the synthesis of 3-alkyl-2-vinyl-aziridines by extension of Dai s work was reported [19]. 

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