Carbonylations alkenes

The carbonyl complex [Ru(EDTAH)(CO)] has been reported to be a very good catalyst for reactions like hydroformylation of alkenes, carbonylation of ammonia and ammines as well as a very active catalyst for the water gas shift reaction. The nitrosyl [Ru(EDTA)(NO)] is an oxygen-transfer agent for the oxidation of hex-l-ene to hexan-2-one, and cyclohexane to the corresponding epoxide. 

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

Electroreductive Cyclization Electron Deficient Alkene/Carbonyl... 

Methane Hydrogen phosphate Ammonium Alkene Carbonyl Aldimine... 

The tin hydride method is reductive, and the cyclic radical is almost always trapped by a hydrogen atom. In simple cyclizations, both the radical precursor and the alkene are lost during tin hydride reduction, and this sometimes results in underfunctionalized products, necessitating the introduction of extra functional groups for subsequent transformations. However, in the synthesis of simple molecules, this is often an advantage as steps to remove residual alkenes, carbonyl groups and the like, left by ionic methods of C—C bond formation, are not required. Work-up requires separation of the desired products from the tin by-products (see Section 4.1.6.2.1). 

The Alder-ene reaction is an atom-economic reaction which forms a new carbon carbon-bond from two double bond systems (alkenes, carbonyl groups, etc.) with double bond migration [5]. This reaction follows the Woodward-Hoffmann rules if the reaction is performed under thermal conditions. However, when transition metal catalysts are involved, thermally forbidden Alder-ene reactions can also be realized (Scheme 9.1). Examples of such processes are the formal [4 + 4]-Alder-ene reaction catalyzed by low-valent iron catalysts. 

Alkyne-alkene carbonylative coupling. Intramolecular carbonylative coupling of dialkynes catalyzed by Fe(CO)3 provides a route to cyclopentadienones (equation I). The more difficult carbonylative alkyne-alkene coupling to provide cyclopen-tenones (Pauson-Khand reaction) can also be effected with Fe(CO)s, but in modest yield. In an improved coupling, acetone is treated with Fe2(CO)9 to form Fe-... 

The alkene carbonylation reaction is not always quite so straightforward thus the carbonylation of ethylene in the presence of an alcohol ROH can give, with a palladium or nickel catalyst, the 7-ketocaproic ester, in addition to the expected propionic ester. The formation of the 7-ketocaproic ester can be rationalized on the basis of the following ligand migration sequence, which... 

The vast majority of work on asymmetric Diels-Alder reactions deals with additions of 1,3-dienes to a, -alkenic carbonyl derivatives XXI) where the chirophore R is attached to the carbonyl group eiAer directly or via a heteroatom X, permitting subsequent removal of the auxiliary (e.g. by attack of a nucleophile Nu Scheme 75). 

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). 

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