A survey of the reactivity of diphenylmagnesium in polymeric solvents

Abstract

Reactions with magnesium-based reagents are often performed in the solvent THF or diethyl ether, both of which are known to contribute to smog formation. A set of reactions with diphenylmagnesium was performed in the following 'greener' solvents: poly(ethylene glycol) dimethyl ether, poly(dimethylsiloxane) trimethylsiloxy terminated, diethylene glycol dimethyl ether, and 2-methyltetrahydrofuran. Products and yields in poly(ethylene glycol) dimethyl ether were expected to be the similar to those found in diethylene glycol dimethyl. The set of reactions included bromination, and hydrolysis of diphenylmagnesium. Additionally, the reaction of diphenylmagnesium with cyclopentanone was performed and the expected product, cyclopenten-1-yl-benzene, was found in very low yields when present at all. Instead, the products were dominated by 1-phenyl-1-cyclopentanol and 2-cyclopentylidene-cyclopentanone. diM-PEG was found to be a poor solvent for both Grignard and diorganomagnesium reagents, while TMS-PDMS as solvent produced high product yields despite not being able to dissolve the diphenylmagnesium.