Alkyne-alkene-carbonyl compounds

Fluoroalkyl(aryl)iodonium salts are the most stable and practically important class of alkyl(aryl)iodonium derivatives. The application of such salts as electrophilic fiuoroalkylating reagents was reviewed in 1996 by Umemoto [1017]. Perfluoroalkyl(phenyl)iodonium trifiates (FITS reagents) 764 are efficient perfluoroalky-lating reagents toward various nucleophiUe substrates, sueh as arenes, carbanions, alkynes, alkenes, carbonyl compounds, amines, phosphines and sulfides [1017]. Scheme 3.300 shows several representative examples of electrophilic perfluoroalkylations using FITS reagents. 

Catalytic Reductive Coupling of Alkenes and Alkynes to Carbonyl Compounds and Imines Mediated by Hydrogen... 

Ihmels H, Otto D (2005) Intercalation of Organic Dye Molecules into Double-Stranded DNA - General Principles and Recent Developments. 258 161-204 Iida H, Krische MJ (2007) Catalytic Reductive Coupling of Alkenes and Alkynes to Carbonyl Compounds and Imines Mediated by Hydrogen. 279 77-104 Imai H (2007) Self-Organized Formation of Hierarchical Structures. 270 43-72 Indelli MT, see Chiorboli C (2005) 257 63-102 Inoue Y, see Borovkov VV (2006) 265 89-146 Ishii A, Nakayama J (2005) Carbodithioic Acid Esters. 251 181-225 Ishii A, Nakayama J (2005) Carboselenothioic and Carbodiselenoic Acid Derivatives and Related Compounds. 251 227-246... 

Isosydnones (146) react with alkynes to give pyrazoles (150). For example, 4,5-diphenylisosydnone (146, R = R = Ph) and ethyl phenyl propiolate gives 4-ethoxycarbonyl-l,3,5-triphenylpyrazole (150, R = R = R = Ph, R = CO Et) identical with the product from 4,5-diphenylsydnone (1, R = R = Ph). The rate of 1,3-cycloaddition for isosydnones (146) is relatively slow in comparison with sydnones (1).2o, 04 number of other cycloaddition reactions of isosydnones with alkenes, alkynes, and carbonyl compounds have been reported. ... 

Chapter 4 centers on two key transformations in organic synthesis (1) oxidation of alcohols and of unsaturated hydrocarbons (i.e., alkenes and alkynes) to carbonyl compounds (2) reduction of various carbonyl compounds to alcohols. 

The term hydrosilation (or hydrosilylation) refers to the addition of a molecule containing a Si-H bond across the multiple bond of a substrate, usually an alkene, alkyne, or carbonyl compound (equation 1). The reaction can be promoted by UV-light, radiation (y- and X rays), radical initiators, Lewis acids, nucleophiles, or, most importantly, transition metal catalysts. Hydrosilation is related to the important processes of hydrogenation (see Hydrogenation) and hydroboration (see Hydroboration), all of which belong to the general reaction class of hydroelementation. 

Alkanes may be prepared by the hydrogenolysis of functional groups such as alkyl halides, by the reduction of imsaturated systems such as alkenes, alkynes and carbonyl compounds and by coupling reactions. The characteristic reactions of alkanes involve the abstraction of a hydrogen atom by a free radical to form a carbon radical. 

The term hydrosilation (or hydrosilylation) refers to the addition of a molecule containing a Si-H bond across the multiple bond of a substrate, usually an alkene, alkyne, or carbonyl compound (equation The reaction can... 

Compounds with multiple bonds are capable of reacting with other molecules so as to acquire only cr bonds. A few such ADDITION reactions are illustrated for alkenes, alkynes, and carbonyl compounds. Ethylene, a typical alkene, reacts with chlorine readily at room temperature ... 

Whereas H—Si of alkenes, alkynes and carbonyl compounds has been much investigated only a few publications deal with the corresponding reduction of CN bonds [42] (Schiff bases, oximes, etc.). 

A NHC-Rh catalyst, [(l,3-dimesityltetrahydropyrimidin-2-ylidene)Rh (CF3C00)(C0D)], was studied for the hydrosilylation of alkenes, alkynes and carbonyl compounds <100% conversion and 1000 TON were observed. Rh complex 136 proved to be an efficient catalyst for the hydrosilylation of terminal alkenes, achieving full conversions at catalyst loadings as low as 0.02 mol% at 60 °C, with high selectivity (Figure 13.15). ... 

Insertion of isocyanides into zirconacyclopentanes and zirconacyclopentenes affords the corresponding zirconocene q -imine complexes. Cyclopentylamine derivatives could be prepared by trapping of the insertion intermediates using alkenes, alkynes, and carbonyl compounds [50]. For example, insertion of phenylisocyanide into bicyclic zirconacyclopentenes affords iminoacyl complexes that rearrange to give a, )0-unsaturated zirconocene q -imine complexes. These complexes react with alkenes or alkynes to give cyclopententylamines (Eq.48) [51]. 

Multiple bonds are revealed clearly by anisotropic effects. Textbook examples include alkynes, shielded along the C=C triple bond, and alkenes and carbonyl compounds, where the nuclei are deshielded in the plane of the C=C and C=0 double bonds, respectively One criterion for distinguishing methyl groups attached to the double bond of pulegone (31), for example, is the carbonyl anisotropic effect. 

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