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Alkyne derivatives hydrocarboxylation

Carboxylic acids and their derivatives like esters, amides, anhydrides, and acyl halides are formally synthesized from olefins, carbon monoxide, and compounds represented by Nu-H such as H2O, ROH, RNH2, RCOOH (Equations (4) and (5)). Alkynes also react under similar conditions to afford the corresponding unsaturated carboxylic acid derivatives. These reactions have been named hydrocarboxylation, hydroalkoxycarbonylation, and hydroaminocarbonylation. [Pg.464]

The hydrocarboxylation reaction of alkenes and alkynes is one which utilizes carbon monoxide to produce carboxylic acid derivatives. The source of hydrogen is a protic solvent (equation 35) dihydrogen is not usually added to the reaction. There are a number of variations to this reaction, since the solvent can be water, alcohols, amines, acids, etc. The catalysts can be Group VIII-X transition metals, but cobalt, rhodium, nickel, palladium and platinum have found the most use. [Pg.932]

When applied to triple bonds, hydrocarboxylation gives a,p-unsaturated acids under very mild conditions. Triple bonds give unsaturated acids and saturated dicar-boxylic acids when treated with carbon dioxide and an electrically reduced nickel complex catalyst. Alkynes also react with NaHFe(CO)4, followed by CuCl2 2 H2O, to give alkenyl acid derivatives. A related reaction with CO and palladium catalysts in the presence of SnCE also leads to conjugated acid derivatives. Terminal alkynes react with CO2 and Ni(cod)2, and subsequent treatment with DBU (p. 1132) gives the a,p-unsaturated carboxylic acid. ... [Pg.1138]

The catalytic hydrocarbonylation and hydrocarboxylation of olefins, alkynes, and other TT-bonded compounds are reactions of important industrial potential.Various transition metal complexes, such as palladium, rhodium, ruthenium, or nickel complexes, have widely been used in combination with phosphines and other types of ligands as catalysts in most carbonylation reactions. The reactions of alkenes, alkynes, and other related substrates with carbon monoxide in the presence of group VIII metals and a source of proton affords various carboxylic acids or carboxylic acid derivatives.f f f f f While many metals have successfully been employed as catalysts in these reactions, they often lead to mixtures of products under drastic experimental conditions.f i f f f In the last twenty years, palladium complexes are the most frequently and successfully used catalysts for regio-, stereo-, and enantioselective hydrocarbonylation and hydrocarboxylation reactions.f ... [Pg.684]

The metal-complex-catalyzed hydrocarboxylation of alkynes is of value for the synthesis of a,/3-unsaturated acids and their derivatives. The direct regioselective hydrocarboxylation of alkynes to a,)8-unsaturated carboxylic acids can be achieved using the catalytic system Pd(OAc)2, dppb, and PPhj in the presence of formic acid at 120 psi of CO and 100-110 °C. The use of a mixture of the two ligands, dppb and PPh3, significantly improves the yields (Eq. 10). ... [Pg.688]

The hydrocarboxylation of activated unsaturated hydrocarbons with 002 is an estabhshed methodology in organic chemistry to yield either a,P- (for alkynes), P,y-unsaturated a-branched (for aUenes and 1,3 alkadienes), or a-branched carboxyhc acid derivatives (for styrenes)/ but requires the stoichiometric use of reductants (i.e., AlEt3, hydrosilanes, RMgX) or... [Pg.177]


See other pages where Alkyne derivatives hydrocarboxylation is mentioned: [Pg.338]    [Pg.155]    [Pg.172]    [Pg.214]   


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