Different Lanthanide Ions and the Pybox Substituents Induce the Reverse of the Sense of Induction in the Enantioselective Diels−Alder Reaction between Acryloyloxazolidinone and Cyclopentadiene
- 29 August 2003
- journal article
- Published by American Chemical Society (ACS) in The Journal of Organic Chemistry
- Vol. 68 (20) , 7862-7866
- https://doi.org/10.1021/jo034215d
Abstract
The Diels−Alder reaction of cyclopentadiene with acryloyl-1,3-oxazolidin-2-one is catalyzed by (R,R)-i-Pr- and (R,R)-Ph-pybox (5 and 6)/lanthanide(III) triflate complexes. The enantioselectivity of the reaction is influenced by 4 Å molecular sieves; moreover, the absolute sense of the enantioselection was found to be a function of the nature of the substituents on the chiral ligand (e.g., aromatic vs alkyl groups) as well as of the specific cation employed. In particular, seven lanthanide triflates were tested and a regular variation of the enantioselectivity as a function of the cation ionic radius was evidenced. The different sense of induction can be rationalized by assuming two competitive reacting complexes with different coordination number, which favor the attack on the opposite heterotopic faces of the coordinated dienophile.Keywords
This publication has 18 references indexed in Scilit:
- Features of organolanthanide complexesPublished by Springer Nature ,2005
- Pyridine-2,6-bis(oxazolines), Helpful Ligands for Asymmetric CatalystsChemical Reviews, 2003
- Defining effective chiral binding sites at lanthanides—highly enantioselective reagents and catalysts from binaphtholate and pybox ligandsJournal of Organometallic Chemistry, 2002
- A new and highly efficient catalyst for the enantioselective Mukaiyama–Michael reaction between ( E )-3-crotonoyl-1,3-oxazolidin-2-one and 2-trimethylsilyloxyfuranTetrahedron, 2001
- Asymmetric glyoxylate-ene reaction catalyzed by C2-symmetric chiral bis(oxazoline)–lanthanide complexesTetrahedron: Asymmetry, 2000
- Lanthanide complexes with C2 symmetric ligands for use in enantioselective organic synthesisJournal of Alloys and Compounds, 2000
- Asymmetric hetero-Diels–Alder reaction of glyoxylate esters and Danishefsky’s diene catalyzed by chiral bis(oxazoline)–lanthanide complexesTetrahedron Letters, 2000
- Bis(oxazoline) and Bis(oxazolinyl)pyridine Copper Complexes as Enantioselective Diels−Alder Catalysts: Reaction Scope and Synthetic ApplicationsJournal of the American Chemical Society, 1999
- C2-Symmetric chiral bis(oxazoline)–metal complexes in catalytic asymmetric synthesisTetrahedron: Asymmetry, 1998
- A chiral samarium-based catalyst for the asymmetric Meerwein-Ponndorf-Verley reductionJournal of the American Chemical Society, 1993