1357471-22-7Relevant articles and documents
Synergistic effects within a C2-symmetric organocatalyst: The potential formation of a chiral catalytic pocket
Delaney, Joshua P.,Brozinski, Hannah L.,Henderson, Luke C.
, p. 2951 - 2960 (2013)
This study describes the synthesis of five novel C2-symmetric organocatalysts that facilitate the on-water asymmetric aldol reaction at low catalyst loading (1 mol%) without the use of additives. Each catalyst is composed of two diprolinamide units joined by a symmetric alkyl bridging group allowing for systematic modulation of catalytic site proximity. Typically, catalysts in this manuscript which bear the catalytic units in close proximity gave the best reaction outcomes in terms of conversion (up to >99%), diastereomeric ratio (4/96, syn/anti) and enantiomeric excess (up to 97%). This effect has been attributed to the assembly of a chiral pocket, facilitated by hydrogen bonding at the oil-in-water interface. The Royal Society of Chemistry 2013.
Direct asymmetric aldol reactions in water catalysed by a highly active C2-symmetrical bisprolinamide organocatalyst
Delaney, Joshua P.,Henderson, Luke C.
, p. 197 - 204 (2012/03/27)
A novel C2-symmetrical bisprolinamide organocatalyst was synthesised and used to facilitate asymmetric direct aldol reactions in a water emulsion. Reactions were performed at room temperature with very low catalyst loadings (1-2.5 mol%) without the required use of additives, co-catalysts or extended reaction times (24 h). This catalyst system was then used with a variety of aldehyde substrates showing good reaction generality for benzaldehydes with cyclohexanone (dr range 77/23 to 99/1, anti/syn; ee range 33% to 99%) and moderate scope with cyclopentanone (dr range 45/55 to 76/24, anti/syn; ee range 14% to 68%). Ultra-low catalysts loadings (0.1 and 0.05 mol%) were also investigated demonstrating catalyst turnover numbers in the order of 1000.
