24612-12-2Relevant academic research and scientific papers
Selective intermolecular coupling of alkynes with nitriles and ketones via ββ′ carbon-carbon bond cleavage of zirconacyclopentenes
Takahashi, Tamotsu,Xi, Chanjuan,Xi, Zhenfeng,Kageyama, Motohiro,Fischer, Reinald,Nakajima, Kiyohiko,Negishi, Ei-Ichi
, p. 6802 - 6806 (1998)
Selective intermolecular coupling of alkynes with nitriles and ketones was performed by the reaction of a mixture of alkynes and Cp2ZrEt2 with nitriles and ketones, respectively. Hydrolysis of the mixture gave α,β-unsaturated ketones and allylic alcohols in good to excellent yields, respectively. These reactions proceeded via zirconacyclopentenes which were prepared by the reaction of alkynes with Cp2ZrEt2. The structure of zirconacyclopentene, which was prepared from diphenylacetylene and Cp2ZrEt2, was determined by X-ray analysis. It clearly indicated that there is a single bond between the β- and β′-carbons of the zirconacyclopentene. The reaction of zirconacyclopentenes with nitriles or ketones proceeded via the β,β′ carbon-carbon bond cleavage of the zirconacyclopentenes. In a similar way, addition of PMes to the zirconacyclopentene afforded a zirconocenealkyne complex in 87% yield.
Iridium-Catalyzed coupling reaction of primary alcohols with 2-alkynes leading to hydroacylation products
Hatanaka, Shintaro,Obora, Yasushi,Ishii, Yasutaka
experimental part, p. 1883 - 1888 (2010/06/20)
A novel iridium-catalyzed intermolecular coupling reaction of primary alcohols or aldehydes with 2-alkynes was successfully achieved with high regioselectivity to give hydroacylation products such as α,β- unsaturated ketones in good yields. The mechanistic investigation of the reaction strongly indicated that the coupling proceeds through the initial formation of homoallylic alcohols followed by dehydrogenation to β,γ-unsatutated ketones and then isomerisation, which leads to the hydroacylation products.
