Carbonyl compounds alkenes

On irradiation with alkenes, carbonyl compounds undergo photocycloaddition to give oxetanes in the Paterno-Biichi reaction ... 

Jorgensen, K. A. Asymmetric Frledel-Crafts reactions Catalytic enantloselective addition of aromatic and heteroaromatic C-H bonds to activated alkenes, carbonyl compounds, and Imlnes. Synthesis 2003,1117-1125. 

Very recently, the use of the electron-deficient allenic esters and ketones 50 as acceptors was also reported by the same group [14], Under PTC conditions (42a (3mol%), o-xylene/CHCl3, K2C03 aq), the cyclic P-ketoester 49 underwent an addition to the electron-deficient allenic esters and ketones 50, giving the corresponding p,y-unsaturated (isolated alkene) carbonyl compounds 51 with excellent enantioselectivity (up to 96% ee, Scheme 9.16). The Michael adduct 51 could be transformed into the optically active hexahydrobenzopyranone 51a and 51b with a 2 1 (51a 51b) diasteromeric ratio via a simple one-step procedure (Scheme 9.17). 

Reactions of ethyl diazoacetates. D can insert into O-H, S-H, and N-H bom I alkenes, carbonyl compounds, and im cyclopropanes, epoxides, and aziridines. i N< presence of MTO and PhjP). 

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. 

Among the factors involved in assessing the effectiveness of direct absorption of light to remove species from the atmosphere are light intensity, quantum yields (chanical reactions per quantum absorbed), and atmospheric mixing. The requirement of a suitable chromophore limits direct photolysis as a removal mechanism for most compounds other than conjugated alkenes, carbonyl compounds, some halides, and some nitrogen compounds, particularly nitro compounds, all of which commonly occur in hazardous wastes. 

Other Reactions. Allyltrimethylsilane reacts with some highly electrophilic alkenes, carbonyl compounds, azo compounds, and singlet oxygen to a greater or lesser extent in ene reactions that do not involve the loss of the silyl group, and hence give vinylsUanes in a solvent-dependent reaction (eq 25). ... 

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