A Simple Primary Amine Catalyst for Enantioselective α-Hydroxylations and α-Fluorinations of Branched Aldehydes
作者:Michael R. Witten、Eric N. Jacobsen
DOI:10.1021/acs.orglett.5b01193
日期:2015.6.5
A new primary amine catalyst for the asymmetric a-hydroxylation and a-fluorination of alpha-branched aldehydes is described. The products of the title transformations are generated in excellent yields with high enantioselectivities. Both processes can be performed within short reaction times and on gram scale. The similarity in results obtained in both reactions, combined with computational evidence, implies a common basis for stereoinduction and the possibility of a general catalytic mechanism for a-functionalizations. Promising initial results in alpha-amination and alpha-chlorination reactions support this hypothesis.
Convenient routes to 2-aryl-2-fluoropropionic acids: Synthesis of monofluorinated analogues of (±)-ibuprofen, (±)-naproxen and related compounds
作者:Olav Goj、Sirpa Kotila、Günter Haufe
DOI:10.1016/0040-4020(96)00758-2
日期:1996.9
The synthesis of α-fluorinated arylpropionic acids 5 as analogues of the nonsteroidal anti-inflammatory agents (NSAIDs) flurbiprofen 1, ibuprofen 3 and naproxen 4 is accomplished by the oxidation of the corresponding primary alcohols 9 The latter are accessible on two different pathways showing their general applicability by variation of the aromatic moiety. Furthermore the influence of the fluorine