Structural Elucidation of the Illustrious Tebbe Reagent

Abstract

The Tebbe reagent, [Cp 2 Ti(μ 2 -Cl)(μ 2 -CH 2 )AlMe 2 ] (1), has finally been structurally characterized due to the fortuitous formation of cocrystals of 1 and [Cp 2 Ti(μ 2 -Cl) 2 AlMe 2 ] (2). Single crystals of 1 and 2, despite being extremely reactive and forming an amorphous white coat, can be mounted and data collected to high resolution, thereby providing for the first time a solid-state representation of a titanium methylidene adduct with diphilic AlClMe 2 .

The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2014

“…The first successful X-ray crystal structure of the Tebbe reagent (cocrystallized with Cp 2 Ti(µ-Cl) 2 AlMe 2 ) was reported [901]. Coupling of the Petasis reagent with alkynes led to metallacyclobutenes (e.g.…”

Chasing Multiple Bonding Interactions between Alkaline‐Earth Metals and Main‐Group Fragments

“…Structuralfeatures of Ae-alkylidene moieties 1-11 two equivalents of AlMe 3 ,w as achieved by the group of Mindiola [103]. The in situ generation of the Schrock-type carbene "[Cp 2 Ti=CH 2 ]" through addition of Lewis bases, for example, pyridine, toT ebbe's reagent is driven by the elimination of the Lewis acid-base adduct [(py)AlMe 2 Cl].A ny efforts to isolate transient" [Cp 2 Ti=CH 2 ]", which acts as ah ighly reactive and selective methylene transfer reagent in Wittig-type reactions, have not been successful [104].…”

Alkyne Cycloaddition to a Titanocene Oxide as a Route to Cyclopentadienyl Modification

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Addition of terminal or internal alkynes to a basefree titanocene oxide results in synthesis of the corresponding oxometallocyclobutene. With appropriate cyclopentadienyl substitution, these compounds undergo reversible CÀC reductive elimination offering a unique approach to cyclopentadienyl modification.Bis(cyclopentadienyl)titanium and zirconium complexes bearing metal-ligand multiple bonds exhibit rich chemistry including olefin metathesis, [1] hydrogenation, [2] CÀH activation, [3,4] cycloaddition, [5] and group transfer processes. [6] Monomeric titanocenes with terminal oxo ligands are a particularly interesting class of these compounds given the unique reactivity of the Ti = O p-system among early transition metal oxides.

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“…Bis(cyclopentadienyl)titanium and zirconium complexes bearing metal-ligand multiple bonds exhibit rich chemistry including olefin metathesis, [1] hydrogenation, [2] CÀH activation, [3,4] cycloaddition, [5] and group transfer processes. [6] Monomeric titanocenes with terminal oxo ligands are a particularly interesting class of these compounds given the unique reactivity of the Ti = O p-system among early transition metal oxides.…”