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46.2.1.1.1 Variation 1: Using the Tebbe Reagent

DOI: 10.1055/sos-SD-046-00028

Takeda, T.; Tsubouchi, A.Science of Synthesis, (20094663.

The Tebbe reagent {(μ-chloro)bis(η5-cyclopentadienyl)(dimethylaluminum)(μ-methyl­ene)titanium; [(AlMe2){Ti(Cp)2}(μ-CH2)(μ-Cl)]} is prepared by the reaction of 2 equivalents of trimethylaluminum with dichlorobis(η5-cyclopentadienyl)titanium(IV).[‌1‌] Because the reagent is highly susceptible to air and moisture, it is more convenient to use it as a standardized solution in benzene or toluene, and such solutions are commercially available from several suppliers. On treatment with a Lewis base such as pyridine or 4-(dimethyl­amino)pyridine, the Tebbe reagent generates bis(η5-cyclopentadienyl)methylenetitani­um(IV) [(Cp)2Ti=CH2], which methylenates carbonyl compounds in the same reaction vessel. Tetrahydrofuran can also be used to promote the generation of bis(η5-cyclopentadi­enyl)methylenetitanium(IV) from the Tebbe reagent.

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8-Meeeeee-8-eeeeeeeeee-8,8-eeeee (8, M8=Me; M8=M8=M; M8=Me); MeeeeeeMeeeeeeee:[‌88‌]

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References


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