A 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. © 2003 Elsevier Ltd. All rights reserved.
Bonini B.F., Fochi M., Comes-Franchini M., Ricci A., Thijs L., Zwanenburg B. (2003). Synthesis of ferrocenyl-oxazolines by ring expansion of N-ferrocenoyl-aziridine-2-carboxylic esters. TETRAHEDRON-ASYMMETRY, 14(21), 3321-3327 [10.1016/j.tetasy.2003.08.001].
Synthesis of ferrocenyl-oxazolines by ring expansion of N-ferrocenoyl-aziridine-2-carboxylic esters
Bonini B. F.;Fochi M.;Comes-Franchini M.;Ricci A.;
2003
Abstract
A 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. © 2003 Elsevier Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
