Recoverable PEG-supported amino alcohol ligand for copper-catalyzed Enantio- and syn-selective henry reaction with nitroethanol: Sustainable and straightforward access to chiral syn-2-nitro-1,3-Diols

Abstract

A poly(ethylene glycol) (PEG) supported amino alcohol has been developed as a chiral ligand to promote the copper-catalyzed asymmetric nitrolaldol reaction (Henry Reaction) with nitroethanol. The catalyst provides direct access to various syn-2-nitro-1,3-diols with high yields and stereoselectivities. The solubility of PEG moiety allows facile purification and recycling of the catalyst. The utility of the catalyst was further demonstrated by the gram-scale preparations of the key intermediates for florfenicol and reboxetine.