Nucleophilic Addition Reactions of Negative Ions with Organometallic Complexes in the Gas Phase

Abstract

Nucleophilic addition and substitution reactions involving metal compounds are among the most widely applied and extensively documented reactions in organometallic chemistry. From the familiar and time-honored Grignard syntheses(1) to the most recent methods for preparing organolanthanides(2) and organoactinides,(3) nucleophilic reactions are found in innumerable synthetic procedures for forming carbon-metal bonds.(4) Nucleophilic addition continues to be the method of choice for preparing anionic transition metal acyls, formyls, hydrides, η3-allyls, η5-cyclohexadienyl complexes, and other lowoxidation-state intermediates for both stoichiometric and catalytic metal-mediated organic synthesis.(5,6) Current efforts to activate CO, CO2, and other small molecules using catalytic cycles in homogeneous solution frequently employ nucleophilic addition strategies in conjunction with transition metal complexes as catalysts.(7,8) For example, the industrially important water-gas shift reaction has been shown to exhibit catalysis in aqueous alkaline solutions containing a wide variety of mono-and polynuclear metal carbonyls.(9–11) Furthermore, the Reppe reaction, the Wacker oxidation, and most homogeneous models for the Fischer-Tropsch process all involve nucleophilic attack on a metal-coordinated ligand during one or more of the key steps in the proposed mechanisms.(5,12–14)