Cobalt-phosphite-catalyzed asymmetric Pauson-Khand reaction.
A complex formed from dicobalt octacarbonyl and a chiral aryl bisphosphite served as a catalyst for the intramolecular asymmetric Pauson-Khand reaction. Bicyclic cyclopentenones were obtained in up to 75% enantiomeric excess. For a terminal 1,6-enyne, the incremental enantiomeric excess was found to increase from 4 to 26% over the course of the reaction. The scope of this process was examined for a variety of 1,6- and 1,7-enynes, and a moderate degree of enantioselectivity was maintained only in the case of aryl-substituted 1,6-enynes.
Sturla
Shana J
SJ
Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Buchwald
Stephen L
SL
D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis*; D002384:Catalysis; D002625:Chemistry, Organic / Q000379:methods*; D003035:Cobalt / Q000737:chemistry*; D003517:Cyclopentanes / Q000138:chemical synthesis*; D004952:Esters / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D017905:Phosphites / Q000737:chemistry*
D001643:Bridged Bicyclo Compounds; D003517:Cyclopentanes; D004952:Esters; D017905:Phosphites; D003035:Cobalt; C013905:cyclopentenone