Organocatalytic and Highly Enantioselective Direct α-Amination of Aromatic Ketones

Abstract

The first highly enantioselective direct alpha-amination of aryl ketones was reported to be catalyzed by organic primary amines derived from cinchona alkaloids. Excellent enantioselectivities (88-99% ee) have been achieved for a broad spectrum of aryl ketones. The presence of 4 A molecular sieves was of great assistance for the high conversions and enantiocontrol.

Recent Advances on the Organocatalyzed Enantioselective α-heterofunctionalization of Carbonyl Compounds

“…Aryl ketones can be also aminated using as catalyst the amine 43 derived from cinchona alkaloids (Figure 4, 20 mol%) [39]. For this reaction, the addition of p-toluenesulfonic acid (40 mol%), and 4 Å molecular sieves were compulsory in order to achieve good enantioselectivities.…”

9-Amino-9-Deoxyepicinchona Alkaloids

“…(8S,9S)-9-amino-9-deoxyepidihydroquinine (A) The highly enantioselective direct a-amination of aryl ketones was reported to be catalyzed by 9-amino-9-deoxyepicinchonine (C 1 ). 3 Excellent enantioselectivities (93~99% ee) have been achieved for a broad spectrum of aryl ketones.…”

Enantioselective Direct α-Amination of Aromatic Ketones Catalyzed by Binaphthyl-Modified Primary Amine

“…Since the first report for proline-catalyzed α-amination of aldehydes, 6 a number of organocatalytic electrophilic α-aminations of simple aliphatic aldehydes and ketones have been reported. 7 Recently, a organocatalytic enantioselective direct α-amination of aromatic ketones has been reported by Chen et al 8 However, this synthetic method suffered some drawbacks such as the high catalyst loading and long reaction time. To overcome these drawbacks, the development of alternative catalysts for the organocatalytic enantioselective direct α-amination of aromatic ketones is highly desirable.…”