Palladium-catalyzed decarbonylation of fatty acid anhydrides for the production of linear alpha olefins

摘要

The present invention is directed to methods of forming olefins, especially linear alpha olefins from fatty acids or anhydrides, each method comprising: contacting an amount of precursor carboxylic acid anhydride with a palladium catalyst comprising a bidentate bis-phosphine ligand in a reaction mixture so as to form an olefin in a product with the concomittant formation and removal of CO and water from the reaction mixture, either directly or indirectly, wherein the reaction mixture is maintained with a sub-stoichiometric excess of a sacrificial carboxylic acid anhydride, an organic acid, or both, said sub-stoichiometric excess being relative to the amount of the precursor carboxylic acid anhydride. The precursor carboxylic acid anhydride may be added to the reaction mixture directly or formed in situ by the reaction between at least one precursor carboxylic acid with a stoichiometric amount of the sacrificial acid anhydride.

主权项

1. A method for forming an olefin product via decarbonylative dehydration of carboxylic acids or carboxylic acid anhydrides, said method comprising contacting:
(a) a precursor carboxylic acid anhydride; (b) a palladium catalyst comprising a bidentate bis-phosphine ligand; and (c) an organic acid selected from the group consisting of substituted benzoic acids and substituted phenols; said contacting done in a reaction mixture under conditions to form an olefin product with the concomitant formation and removal of CO and water from the reaction mixture; wherein the bidentate bis-phosphine ligand comprises a structure of Formulae (I), (II), or (III);wherein
(i) Z is —O—; —S—; methylene; —C(R)2—; —C(═CR2)—; —P(aryl)-; —P(heteroaryl)-; —Si(R)2—; or —N(R)—; (ii) each R is independently at each occurrence H, lower alkyl, aryl, or aralkyl; and (iii) X is independently at each occurrence H, F, Cl, C1-3 alkyl, or C1-3 alkoxide; the method further comprising adding a sacrificial carboxylic acid anhydride to the reaction mixture during the formation of the olefin product, the sacrificial carboxylic acid anhydride being added in one or more portions each of which is sub-stoichiometric with respect to the precursor carboxylic acid anhydride.