Yves Colleuille

Methanol hydrocarbonylation into acetaldehyde catalyzed by cobalt and two different iodides

Abstract The cobalt-catalyzed hydrocarbonylation of methanol into acetaldehyde is discussed. The nature of the iodide promoter has a decisive influence on the reaction rate, the covalent CH3I being much more active than the ionic LI, KI, MePBu3I. A surprising synergistic effect is found when using a mixture of both covalent and ionic iodides.

Metathesis of functionalised olefins: homogeneous cross-metathesis of cycloolefin and ethylenic esters

Abstract The factors (nature of the functional group, distance between the double bond and the functional group) governing the metathesis of functionally substituted olefins were studied for the catalyst WCl 6 /Sn (CH 3 ) 4 . A new route to long-chained linear mono and diesters was thus achieved through cross-metathesis between two easily available compounds: cyclooctene and ethyl-3-pentenoate. Arguments are presented concerning the initiation, the propagation and the termination step.

Catalytic activity of RhH(CO)(PPh3)3 in the presence of thiol: A new way of obtaining a very active species

Abstract Addition of the thiol t-BuSH to RhH(CO)(PPh 3 ) 3 either under nitrogen under ambient conditions or under CO/H 2 pressure under hydroformylation conditions generates the much more active dinuclear species Rh 2 (μ-S-t-Bu) 2 (CO) 2 (PPh 3 ) 2 .