News Archive 2014

Acid choice flips enantioselectivity

Wednesday, 10 December, 2014 

Professor Pat Guiry, Director of the Centre for Synthesis and Chemical Biology, provides some background to recent articles featured in Chemistry World and Chemical & Engineering News based on the work of Prof Guiry's research team in the UCD Centre for Synthesis and Chemical Biology:

"We have recently become interested in applying a palladium-catalyzed decarboxylative asymmetric protonation methodology to the preparation of sterically hindered alpha-aryl ketones, important structural motifs in many medicinally active compounds.

Prof Brian Stoltz (Caltech) had applied his methodology to alpha-alkyl ketones but we managed to extend this to aryl-containing substrates with ees up to 92% when Meldrum's acid was the proton source. We published our original work in Chem Comm in 2012, 48, 11142--11144. Since then we wished to extend this to naturally occurring isoflavanones and investigated 7-oxygenated examples.

During that study we examined Meldrum's acid and formic acid as the H+ sources and we were amazed to find a remarkable switch in enantioselectivity from 92% (R) to 91% (S), as a result of changing the H+ source from Meldrum's acid and formic acid, respectively."