A bis(amino)cyclopropenylidene (BAC) catalyzed aza-benzoin reaction between aldehydes and phosphinoyl imines has been developed. The reaction is general with a wide range of aromatic aldehydes and aromatic imines. The reaction displays excellent chemoselectivity favoring aza-benzoin products over homobenzoin products.
Polymer-supported l-prolinol-based catalysts for the enantioselective addition of dialkylzinc reagents to N-(diphenylphosphinyl)imines
作者:Raquel Almansa、Juan F. Collados、David Guijarro、Miguel Yus
DOI:10.1016/j.tetasy.2012.12.007
日期:2013.2
Merrifield or Wang-type resins have been shown to form efficient catalysts for the enantioselective addition of dialkylzinc reagents to N-(diphenylphosphinyl)imines. The enantioselectivity achieved with the polymeric catalyst (ee up to 88%) is slightly lower than the one obtained with the homogeneous ligand N-benzyl-l-prolinol, but the polymer-supported ligand presents the advantage of its recyclability: it