Organic co-solvents in aqueous DNA-based asymmetric catalysis.
Water-miscible organic co-solvents can be used in DNA-based catalytic asymmetric reactions at appreciable concentration without a negative effect on enantioselectivity. While the rate of the copper(II) Diels-Alder reaction is affected negatively by the presence of organic co-solvents, the copper(II) catalyzed Michael addition and Friedel-Crafts alkylation reaction are significantly faster. Additionally, the presence of organic co-solvents allows for reaction temperatures <0 degrees C, which results in higher ee's. This is used to perform enantioselective Michael additions and Friedel-Crafts alkylations at gram scale, using catalyst loadings as low as 0.75 mol%. These results are an important step towards application of the DNA-based catalysis concept in organic synthesis.
Megens
Rik P
RP
Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, Groningen, The Netherlands.
Roelfes
Gerard
G
D002384:Catalysis; D004247:DNA / Q000737:chemistry*; D007700:Kinetics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009930:Organic Chemicals / Q000138:chemical synthesis / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D013237:Stereoisomerism; D013379:Substrate Specificity; D013696:Temperature; D014867:Water / Q000737:chemistry*
D009930:Organic Chemicals; D012997:Solvents; D014867:Water; D004247:DNA