Hydrogenation noncatalytic methods

In general, hydroboration—protonolysis is a stereoselective noncatalytic method of cis-hydrogenation providing access to alkanes, alkenes, dienes, and enynes from olefinic and acetylenic precursors (108,212). Procedures for the protonolysis of alkenylboranes containing acid-sensitive functional groups under neutral or basic conditions have been developed (213,214). 

This chapter is devoted to the discussion of the reduction of carbon-carbon double and triple bonds by noncatalytic methods, These methods include reductions by diimide, by dissolving metals in the presence or absence of proton donors, by low-valent metal ions, by metal hydride-metal halide combinations and by so-called ionic hydrogenation procedures. Of these widely diverse methods of reduction of carbon-carbon double and triple bonds, the reduction by diimide appears to be the most versatile. The reduction of carbon-carbon double and triple bonds by diimide occurs with complete stereoselectivity and stereo-specificity, and can be effected in the presence of a variety of other, very chemically reactive functional... 

The earliest examples of analytical methods based on chemical kinetics, which date from the late nineteenth century, took advantage of the catalytic activity of enzymes. Typically, the enzyme was added to a solution containing a suitable substrate, and the reaction between the two was monitored for a fixed time. The enzyme s activity was determined by measuring the amount of substrate that had reacted. Enzymes also were used in procedures for the quantitative analysis of hydrogen peroxide and carbohydrates. The application of catalytic reactions continued in the first half of the twentieth century, and developments included the use of nonenzymatic catalysts, noncatalytic reactions, and differences in reaction rates when analyzing samples with several analytes. 

Catalytic steam reforming could also be performed on natural gas (mainly methane) or the heavy fraction of crude oil called naphtha or fuel oil. The old method of producing synthesis gas by passing steam over red-hot coke was noncatalytic. Depending on the requirement for hydrogen, synthesis gas could be further enriched in hydrogen by the following reaction ... 

The underlying concept of this method for the synthesis of filamentous carbonaceous nanomaterials is fairly simple. As the temperature rises above a certain limit, which depends on the thermodynamic and kinetic para meters of carbon containing compounds, such as hydrocarbons, such compounds tend to pyrolyze in the air free conditions to form free carbon. For example, the noncatalytic pyrolysis of methane can be achieved at ambient pressure and at temperatures above 900—1000 K to produce soot (near spherical nanosized carbon particles) and hydrogen ... 

Many methods have been used in the past to produce hydrogen sulfide. The classical method consisted of iron sulfide plus an acid (usually hydrochloric). It also can be made by combining sulfur with hydrogen in a noncatalytic reactor at elevated temperature. 

Olefins can also be hydroborated to organoboranes which are then converted to the hydrocarbon by refluxing with propionic acid [1]. This procedure is a convenient noncatalytic laboratory method for the hydrogenation of olefins. 

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