59862-93-0Relevant articles and documents
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.
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.
