Direct catalytic enantioselective amination of ketones for the formation of tri- and tetrasubstituted stereocenters

Chem Sci. 2018 Feb 14;9(11):2975-2980. doi: 10.1039/c8sc00147b. eCollection 2018 Mar 21.

Abstract

Herein, we report a Zn-ProPhenol catalyzed direct asymmetric amination reaction of unactivated aryl and vinyl ketones using di-tert-butyl azodicarboxylate as a cheap and practical electrophilic nitrogen source. Importantly, this methodology works with both α-branched and unbranched ketones for the construction of tri- and tetrasubstituted N-containing stereocenters. The reaction can be run at gram-scale with low catalyst loadings and features a recoverable and reusable ligand. Finally, the enantioenriched hydrazine products can be readily converted into versatile building blocks such as α-amino carbonyl compounds and β-amino alcohols.