Synthesis of Oxazoles by Tandem Cycloisomerization/Allylic Alkylation of Propargyl Amides with Allylic Alcohols: Zn(OTf)<sub>2</sub> as π Acid and σ Acid Catalyst
A Zn(OTf)(2)-catalyzed tandem cycloisomerization/allylic alkylation of N-(propargyl)arylamides and allylic alcohols to produce Oxazole derivatives has been successfully developed. The zinc catalyst served as pi acid and also sigma acid in this reaction. The target allylic oxazoles have been transformed into multisubstituted diene Structures, which are potential aggregation-induced emission active Optical materials.
Enantioselective synthesis of succinic acids and γ-lactones via palladium catalysed allylic substitution reactions
acetates and sodiodimethylmalonate proceeds in high yields and enantioselectivities (up to 99% ee) using a diphenylphosphinoaryl oxazoline ligand. The so-formed substitution products are transformed into enantiomerically enriched succinicacids and also into enantiomerically enriched γ-lactones.