Polarized multiple bonds organometallics

Organometallics react with this sink by addition to the multiple bond (path Ad r). The more covalent, less reactive organometallics, like R2Cd, react very slowly with almost all of these sinks, whereas organomagnesiums, RMgX, and organolithiums react quickly. Complexation of the metal ion to the Y heteroatom catalyzes this reaction. Organometallics react much faster as nucleophiles with polarized multiple bonds than as bases with the adjacent C-H bonds, (carbon-acid, carbon-base proton transfer is slow). C=Y example ... 

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