Tebbe Olefination

The Tebbe Reagent is a metal carbenoid prepared from the dimetallomethylene species derived by the reaction of trimethyl aluminium with titanocene dichloride; this reagent exhibits carbenoid behaviour after the addition of a catalytic amount of pyridine. The Tebbe Reagent reacts with various carbonyl partners to give the product of methylenation:

Aldehydes to alkenes

Ketones to alkenes

Esters to enol ethers

Amides to enamines

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Mechanism of the Tebbe Olefination