Organomagnesium ions

E. Gas-phase Fragmentation of Ligated Magnesium ions to Yieid Organomagnesium ions... 

Organolithium and organomagnesium reagents are highly reactive toward most carbonyl compounds. With aldehydes and ketones, the tetrahedral adduct is stable, and alcohols are isolated after protonation of the adduct, which is an alkoxide ion. 

The reduction of carbonyl compounds by reaction with hydride reagents (H -) and the Grignard addition by reaction with organomagnesium halides (R - +MgBr) are examples of nucleophilic carbonyl addition reactions. What analogous product do you think might result from reaction of cyanide ion with a ketone ... 

Addition of an excess of organolithium or organomagnesium reagents to germanium halides results in the deplacement of the halide ions and the formation of tetra-alkyl and -arylgermanium compounds. Representative examples of these reactions are shown in equations 4 and 5, respectively. 

Finally, two studies have reported on the reactions of carbocations with Mg atoms using mass spectrometry The types of products formed depend on the nature of the carbocation. The labeled methanium ion, CH4D+, reacts via proton transfer (equation 11), deuteron transfer (equation 12) and charge transfer (equation 13). The ethyl cation reacts via charge transfer (equation 14) while the tert-butyl cation reacts via proton transfer (equation 15). In all cases there was no evidence for formation of an organomagnesium species. 

Addition of organometallics will not be considered in detail here we wish merely to note that additions of organolithium and organomagnesium compounds are analogous to the processes that have been considered up to this point.36 Although the detailed structure of these organometallics may vary from one compound to another, and may in some cases be unknown, they consist essentially of a strong, soft carbon Lewis base coordinated to a hard metal ion Lewis acid.37 Combination... 

Generally carried out under basic conditions, often starting from the organozinc or organomagnesium derivative of an a-bromoester, the Reformatsky reaction. Equilibrium is shifted toward product by formation of a chelate structure with the metal ion. 

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