Tebbe реактив.

The Tebbe reagent is the organometallic compound with the formula (CH)TiCHClAl(CH). It is used in the methylenation of carbonyl compounds, that is it converts organic compounds containing the RC=O group into the related RC=CH derivative.It is a red solid that is pyrophoric in the air, and thus is typically handled with air-free techniques. It was originally synthesized by Fred Tebbe at DuPont Central Research. Tebbe's reagent contains two tetrahedral metal centers linked by a pair of bridging ligands. The titanium has two cyclopentadienyl ([CH]-, or Cp) rings and aluminium has two methyl groups. The titanium and aluminium atoms are linked together by both a methylene bridge (-CH-) and a chloride atom in a nearly square-planar (Ti–CH–Al–Cl) geometry.The Tebbe reagent was the first reported compound where a methylene bridge connects a transition metal (Ti) and a main group metal (Al).Preparation The Tebbe reagent is synthesized from titanocene dichloride and trimethylaluminium in toluene solution.

μ-Chloro-μ-methylenebis(cyclopentadienyl)titaniumdimethylaluminum is used in organic synthesis for carbonyl methylenation, A versatile methylenation reagent for the conversion of ketones and aldehydes to olefins, it offers facile reaction with hindered ketones and allows the conversion of esters to vinyl ethers. Tebbe reagent can be used to olefinate aldehydes, to methylenate a chiral polyhydroxyketone with high diasteroselctivity.

Tebbe reagent is a Lewis acid stabilized organometallic compound, which is used to transform carbonyl groups into β-substituted methylenes. It also reacts with a wide range of carbonyl compounds, including esters, amides, and lactones to yield corresponding olefins.