Iridium-Catalyzed Highly Enantioselective Transfer Hydrogenation of Aryl N-Heteroaryl Ketones with N-Oxide as a Removable ortho-Substituent.
Author | |
---|---|
Abstract |
:
A highly enantioselective transfer hydrogenation of non-ortho-substituted aryl N-heteroaryl ketones, using readily available chiral diamine-derived iridium complex (S,S)-1f as a catalyst and sodium formate as a hydrogen source in a mixture of H2O/i-PrOH (v/v = 1:1) under ambient conditions, is described. The chiral aryl N-heteroaryl methanols were obtained with up to 98.2% ee by introducing an N-oxide as a removable ortho-substituent. In contrast, no more than 15.1% ee was observed in the absence of an N-oxide moiety. Furthermore, the practical utility of this protocol was also demonstrated by gram-scale asymmetric synthesis of bepotastine besilate in 51% total yield and 99.9% ee. |
Year of Publication |
:
2018
|
Journal |
:
Organic letters
|
Date Published |
:
2018
|
ISSN Number |
:
1523-7060
|
URL |
:
https://dx.doi.org/10.1021/acs.orglett.7b03878
|
DOI |
:
10.1021/acs.orglett.7b03878
|
Short Title |
:
Org Lett
|
Download citation |