Aldehydes decarbonylation, diphosphine

The above data which are presented in Tables I-IV show that the diphosphine complexes are effective catalysts for the aldehyde decarbonylation. Although these reactions tolerate various functional groups such as carboxylic acids, ethers, ketones, olefins, and aryl chlorides,... 

CATALYTIC DECARBONYLATION OF ALDEHYDES WITH CATIONIC DIPHOSPHINE COMPLEXES OF Rh(l)... 

The rates of catalytic decarbonylation of benzaldehyde using mono-diphosphine complexes of Rh and Ir provide an interesting comparison. First of all, the mono-diphosphine complexes of Rh and Ir are not robust under the conditions of the catalytic reaction and therefore are of little practical use. However, they do provide useful data for mechanistic arguments. With Rh, the bis-diphosphine catalysts [Rh(P-P)2] are always more active than their mono-diphosphine analog [Rh(P-P)] when neat aldehyde is used as solvent. Although Rh-P bond rupture is not necessary with the coordinatively unsaturated mono-diphosphine complexes, the rhodium may not be electron-rich enough to promote facile oxidative addition. In support of this argument, the presence of the diolefin cod in the coordination core, [Rh(cod)(dppp)]", increased the activity of decarbonylation by a factor of 6 compared with [Rh(dppp)]. With Ir... 

---