Synthesis of ferrocenyl-oxazolines by ring expansion of N-ferrocenoyl-aziridine-2-carboxylic esters
2003; Elsevier BV; Volume: 14; Issue: 21 Linguagem: Inglês
10.1016/j.tetasy.2003.08.001
ISSN1362-511X
AutoresBianca F. Bonini, Mariafrancesca Fochi, Mauro Comes Franchini, Alfredo Ricci, L. Thijs, B. Zwanenburg,
Tópico(s)Sulfur-Based Synthesis Techniques
ResumoA synthesis of ferrocenyl-oxazolines is described using an iodide-mediated ring expansion of N-ferrocenoyl-aziridine-2-carboxylic esters. The ring enlargements take place with full stereocontrol, namely net retention of configuration. Modification of the ester function by a Grignard reaction leads to three new types of ferrocenyl-oxazoline carbinol ligands, which were used as chiral ligands in the asymmetric addition of diethylzinc to benzaldehyde (e.e.s ranging from 46 to 62%). The planar chiral ferrocenyl-oxazoline carbinol ligand gave a very good result (e.e. 90%) in the palladium-catalyzed allylic substitution of 1,3-diphenyl prop-2-enylacetate with dimethyl malonate.
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