59862-93-0Relevant academic research and scientific papers
Tandem Regioselective Hydroformylation-Hydrogenation of Internal Alkynes Using a Supramolecular Catalyst
Fang, Weiwei,Breit, Bernhard
supporting information, p. 14817 - 14821 (2018/10/24)
New supramolecular ligands containing an acyl guanidine function were designed based on the strategy of increasing the π-acceptor ability of phosphine ligands by introducing electron-withdrawing groups. By applying this novel catalytic system, a general protocol for the Rh-catalysed hydroformylation-hydrogenation of unsymmetrical internal alkynes, functionalized with a carboxylic acid, was found to furnish aliphatic aldehydes in high regio- and chemoselectivities. Control experiments confirm the enzyme-like supramolecular catalyst mode of action.
Palladium(II)-Catalyzed Directed anti-Hydrochlorination of Unactivated Alkynes with HCl
Derosa, Joseph,Cantu, Annabelle L.,Boulous, Mark N.,O'Duill, Miriam L.,Turnbull, Joshua L.,Liu, Zhen,De La Torre, Daizy M.,Engle, Keary M.
supporting information, p. 5183 - 5193 (2017/05/04)
A regioselective anti-hydrochlorination of unactivated alkynes is reported. The reaction utilizes in situ generated HCl as the source of both the Cl- and H+ and is catalyzed by palladium(II) acetate, with loadings as low as 25 ppm. Removable picolinamide and 8-aminoquinoline bidentate directing groups are used to control the regioselectivity of the chloropalladation step and stabilize the resulting alkenylpalladium(II) intermediate for subsequent protodepalladation. This method provides access to a broad array of substituted alkenyl chlorides in excellent yields and with high regioselectivity. The products from this transformation were successfully derivatized via Stille coupling to a variety of trisubstituted alkene products. Reaction progress kinetic analysis was performed, shedding light on a possible mechanism for this catalytic process.
Enantioselective Bronsted acid-catalyzed N-acyliminium cyclization cascades
Muratore, Michael E.,Holloway, Chloe A.,Pilling, Adam W.,Storer, R. Ian,Trevitt, Graham,Dixon, Darren J.
supporting information; experimental part, p. 10796 - 10797 (2009/12/03)
(Chemical Equation Presented) An enantioselective Bronsted acid-catalyzed N-acyliminium cyclization cascade of tryptamines with enol lactones to form architecturally complex heterocycles in high enantiomeric excess has been developed. The reaction is technically simple to perform as well as atom-efficient and may be coupled to a gold(I)-catalyzed cycloisomerization of alkynoic acids whereby the key enol lactone reaction partner is generated in situ. Employing up to 10 mol % bulky chiral phosphoric acid catalysts in boiling toluene allowed the product materials to be generated in good overall yields (63-99%) and high enantioselectivities (72-99% ee). With doubly substituted enol lactones, high diastereo- and enantioselectivities were obtained, thus providing a new example of a dynamic kinetic asymmetric cyclization reaction.
Chromium catalyzed oxidation of (homo-)allylic and (homo-)propargylic alcohols with sodium periodate to ketones or carboxylic acids
De Vondervoort, Lizette Schmieder-Van,Bouttemy, Sabine,Padrón, José M.,Le Bras, Jean,Muzart, Jacques,Alsters, Paul L.
, p. 243 - 246 (2007/10/03)
Primary and secondary (homo-)allylic and (homo-)propargylic alcohols can be oxidized under slightly acidic conditions at or below room- temperature with sodium periodate in the presence of sodium dichromate as the catalyst to the corresponding carboxylic acids and ketones, respectively.
