Me2Zn mediated, tert-butylhydroperoxide promoted, catalytic enantioselective Reformatsky reaction with aldehydes
作者:Pier Giorgio Cozzi、Fides Benfatti、Montse Guiteras Capdevila、Alessandro Mignogna
DOI:10.1039/b805197f
日期:——
A practical and highly enantioselectivecatalyticReformatskyreaction with aldehydes using a cheap, commercially available aminoalcohol as ligand is described.
Three new biaryl phosphine ligands 4a-c have been prepared and their application in the Ru-catalyzed asymmetric hydrogenation of beta-ketoesters investigated. Ruthenium catalysts containing these ligands are highly effective in the hydrogenation of beta-ketoesters with up to 99.9% ee being obtained. (C) 2004 Elsevier Ltd. All rights reserved.
Synthesis of a Bulky and Electron-Rich Derivative of SEGPhos and Its Application in Ru-Catalyzed Enantioselective Hydrogenation of β-Ketoesters
electron-rich derivative of SEGPhos and its application in Ru-catalyzed asymmetric hydrogenation reaction of β-ketoesters are reported. Up to 99.5% ee was achieved. Under solvent-free reaction conditions, acetoacetates could be reduced with good enantioselectivity and high efficiency; a TON of 20 000 was obtained within 3.5 h. The results obtained were comparable to those when SEGPhos was applied.