ChemInform Abstract: Chiral Catalyst Controlled Diastereoselection and Regioselection in Intramolecular Carbon-Hydrogen Insertion Reactions of Diazoacetates.

✍ Scribed by M. P. DOYLE; A. V. KALININ; D. G. ENE

• Publisher: John Wiley and Sons
• Year: 2010
• Weight: 29 KB
• Volume: 28
• Category: Article
• ISSN: 0931-7597
• DOI: 10.1002/chin.199704120

✦ Synopsis

The individual enantiomers of substituted cyclohexyl diazoacetates (I)-(IV) or 2-octyl diazoacetates (V) matched with a configurationally suitable chiral dirhodium(II) carboxamidate catalyst provide an effective methodology for the synthesis of lactones with exceptional diastereoand regiocontrol. The data demonstrate that the chiral ligands on dirhodium(II) have a remarkable influence on the diastereo-and regiocontrol in the C-H insertion reactions. Mechanistic considerations reveal that the chiral dirhodium(II) carboxamidates not only inhibit competing reactions but also orient the attached carbene for efficient intramolecular C-H insertion. The appropriate match of catalyst and substrate configurations ensures production of single diastereoisomers/regioisomers in C-H insertion reactions. -(DOYLE, M. P.;