Olefin hydrogenation Michael addition

Hydrogen cyanide adds to an olefinic double bond most readily when an adjacent activating group is present in the molecule, eg, carbonyl or cyano groups. In these cases, a Michael addition proceeds readily under basic catalysis, as with acrylonitrile (qv) to yield succinonitnle [110-61-2], C4H4N2, iu high yield (13). Formation of acrylonitrile by addition across the acetylenic bond can be accompHshed under catalytic conditions (see Acetylene-DERIVED chemicals). 

In addition to a-additions to isocyanides, copper oxide-cyclohexyl isocyanide mixtures are catalysts for other reactions including olefin dimerization and oligomerization 121, 125, 126). They also catalyze pyrroline and oxazoline formation from isocyanides with a protonic a-hydrogen (e.g., PhCH2NC or EtOCOCHjNC) and olefins or ketones 130), and the formation of cyclopropanes from olefins and substituted chloromethanes 131). The same catalyst systems also catalyze Michael addition reactions 119a). 

Addition of Compounds Containing an Active Hydrogen Atom to Olefinic Compounds (Michael)... 

The important intermediate 66 of the steroid synthesis has been prepared by the application of the same reaction sequence to 2-methyl-1,3-cyclohexanedione (65) (Scheme 22). A synthesis of (+) 19-nortestosterone (69) starts with the Michael addition of the optically active oxo ester 67 to 1,7-octadien-3-one (59) catalyzed by sodium hydride, the ester group being removed by heating in aqueous HMPA with sodium iodide to give the dione 68. The aldol condensation catalyzed by sodium hydroxide proceeds in 90% yield. The terminal double bond is oxidized with PdCl2/CuCl to the methyl ketone and the internal olefinic double bond subsequently hydrogenated. The final reaction step involves aldol condensation in refluxing... 

Synthesis of diamines 1 typicaliy involves Michael addition of a glycol to a conjugated olefinic nitrile followed by catalytic hydrogenation of the dinitrile to give the primary diamine. 

But catalytic reduction of the same phenyl propionic acid gives cis cinnamic acid. Therefore by adding hydrogen under various conditions, one can obtain a desired isomer. The conversion of acetylene into olefinic compounds has been carried out not only for the sake of obtaining the adduct, but Michael studied the various addition reactions for the sake of obtaining a desired product cis or trans. For example, he found that the addition of bromine to acetylene-dicarboxylic acid leads predominantly to the formation of trans isomer. 

The addition of hydrogen cyanide (HCN) to carbon-carbon double bonds activated by electron-withdrawing groups in the presence of a base as a catalyst (a variation of the Michael Reaction) has been known for a long time. Nitriles were also obtained by hydrocyanation of branched olefins, such as isobutylene and trimethylethylene, in vapor phase reactions in particular the reactions over alumina (3) and cobalt-on-alumina (4) were reported in the late 1940s and early 1950s. Addition of HCN to conjugated dienes in the presence of cuprous salts (vapor and liquid phase) was reported as early as 1947 (5). 

Important laboratory applications involve the addition of hydrogen cyanide to an olefinic linkage which is activated by another group such as carbonyl, carbalkoxyl, cyano, or nitro on the adjacent carbon /3-cyano compounds are formed. The reaction is related to the Michael condensation (method 301). For the most part, the additions are base-catalyzed and are carried out by treating the unsaturated compound with an alkali cyanide in aqueous or aqueous-alcoholic solution. 

OYEs are oxidoreductases that catalyze the addition of the elements of hydrogen to an electron-poor olefinic double bond in a stereospecific trans-manner [6]. The hydride is delivered from reduced flavin mononucleotide (FMNH2) in a Michael-type process, the proton being donated by a tyrosine residue [8] or by water [9,10] in the so-called oxidative half-reaction (Figure 5.1). NAD(P)H in the reductive half-reaction ensures reduction of the flavin [6]. Mechanistically... 

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