Process for preparing diketonato-rhodium(I)-carbonyl complexes

摘要

The invention relates to a process for preparing diketonato-rhodium(I)-carbonyl complexes, especially diketonato-rhodium(I)-triorganophosphine-carbonyl complexes, for example Rh(CO)(PPh3)acac. The process according to the invention is a “one-pot synthesis” and features a process procedure without intermediate isolation stages. After introduction of an Rh(III) halide precursor into a solvent and sparging with carbon monoxide (CO), a diketo compound of the R′—C(═O)—CH2—C(═O)—R″ type and a base are added, forming the intermediate compound diketonato-Rh(CO)2. After addition of a triorganophosphine of the PR3 type, the reaction mixture is heated and the diketonatocarbonyltriorganophosphine-rhodium(I) complex is removed. The process enables a rapid operation and a high yield. The complex Rh(CO)(PPh3)acac prepared in accordance with the invention, because of its purity, is particularly suitable as a catalyst or precatalyst for homogeneous catalysis, for example for hydroformylation reactions.

主权项

1. A process for preparing the diketonatocarbonyltriorganophosphinerhodium(I) complex having the formula (I) where R is C1-C10-alkyl, C5-C10-cycloalkyl, C6-C12-aryl, or C4-C12-heteroaryl and R′ and R″ are each, independent of one another, a C1-C5-alkyl, C5-C10-cycloalkyl, or C6-C12-aryl, where R, R′ and R″ may optionally be substituted, which comprises the reaction steps: (a) introduction of an Rh(III) halide precursor into a solvent, (b) treatment with carbon monoxide (CO) gas, (c) addition of a diketo compound of the type R′—C(═O)—CH2—C(═O)—R″ and a base, forming the intermediate (diketonato)Rh(CO)2, (d) addition of a triorganophosphine of the type PR3, (e) heating of the reaction mixture and isolation of the diketonatocarbonyltriorganophosphinerhodium(I) complex of the formula (I), and wherein the solvent of step (a) is used as a solvent throughout the process.