Magnesiumorganische Innerkomplexe, Teil II [1]. Ethyl(dialkylaminoalkyl)- und Ethyl(4-alkoxybutyl)magnesium-Verbindungen / Organomagnesium Inner Complexes, Part II [1]. Ethyl(dialkylaminoalkyl)- and Ethyl(4-alkoxybutyl)magnesium Compounds

Abstract

<jats:title>Abstract</jats:title><jats:p> The reaction of bis(dialkylaminoalkyl)-and bis(4-alkoxybutyl)magnesium inner complexes with MgEt<jats:sub>2</jats:sub> leads to the formation of ethyl(dialkylaminoalkyl)-and ethyl(4-alkoxybutyl)magnesium compounds. The X-ray crystal structures of ethyl(3-N,N-dimethylam inopropyl)magnesium and ethyl(3-N-cyclohexyl-3-N-methylaminopropyl)magnesium confirm that the com pounds are dimeric with the α-C-atom of the chelating ligand bridging the magnesium atoms.</jats:p><jats:p>The difference in reactivity of the Mg-Et and Mg-C<jats:sub>n</jats:sub>H<jats:sub>2n</jats:sub>X bonds (X = NR′R″, OR) makes itself apparent in the reaction of these complexes with ethylene: up to six ethylene molecules are inserted, whereby in the case of the ethyl(4-alkoxybutyl)magnesium compounds insertion occurs preferentially into the Mg-Et bond whereas in the case o f the ethyl(dialkylaminoalkyl)magnesium compounds both bonds are equally reactive.</jats:p>

Intramolecular Coordination in Organometallic Compounds of Groups 2, 12, and 13

“…This was investigated by means of insertion reactions of ethylene or reactions with CO2, benzaldehyde and isobutyl methyl ketone. 41 The reactions with ethylene are shown in Scheme 23. Generally, the Mg-Et bond was slightly more reactive (more products of type E than of type D), especially when the donor atom was oxygen.…”

“…The thermolysis reaction of the ethyl[(dialkylamino)alkyl]-and ethyl(4-alkoxybutyl)magnesium IC complexes was compared to that of diethylmagnesium. 41 The thermolysis of Et^Mg proceeds in two (Scheme 24). With the IC compounds, a different process is operating: at 190-200 °C (oxygen compounds) or at 210-220 °C (nitrogen compounds), thermolysis occurred, the gas produced being ethane instead of ethylene.…”

“…Addition of an ethereal solution of allylmagnesium bromide and zinc dibromide to an ethereal solution of a functionalized vinyllithium compound at -20 °C lead to the formation of the stable organobimetallic compound 66, as evidenced by the fact that quenching of the reaction mixture with HC1 (or DC1) afforded the expected dideuterated alkene (Scheme 41).59 On Scheme 41 warming the reaction mixture very slowly to room temperature, 66 underwent a diastereoselective 1,3elimination to give a single isomer of a metalated cyclopropane.…”