1152170-60-9Relevant articles and documents
Dual pathway for the asymmetric transfer hydrogenation of α-ketoimides to chiral α-hydroxy imides or chiral α-hydroxy esters
Zhao, Qiankun,Zhao, Yuxi,Liao, Hang,Cheng, Tanyu,Liu, Guohua
, p. 412 - 416 (2016/02/05)
In an enantioselective reaction, we expect to obtain two types of chiral products through a controllable strategy in asymmetric catalysis. Herein, we develop Ru-catalysed asymmetric transfer hydrogenation of α-ketoimides to realise an enantioselective construction of chiral α-hydroxy imides or chiral α-hydroxy esters. The transformation of α-ketoimides catalysed by (S,S)-[RuCl(η6-mesitylene)diamine] can afford various chiral α-hydroxy imides with high yields and enantioselectivities, whereas that catalysed by (S,S)-[RuCl(η6-hexamethylbenzene)diamine] gives the desirable chiral α-hydroxy esters through a slight adjustment of the reaction conditions. The method described here is a controllable organic transformation with sodium formate as a hydrogen source under mild reaction conditions, and the benefit of this transformation is that various chiral α-hydroxy imides or α-hydroxy esters can be obtained selectively from α-ketoimides. Selective directive: An enantioselective transformation in the Ru-catalyzed asymmetric transfer hydrogenation of α-ketoimides to chiral α-hydroxy imides or α-hydroxy esters is developed. The transformation of α-ketoimides catalyzed by (S,S)-[RuCl(η6-mesitylene)diamine] can afford various chiral α-hydroxy imides with high yields and enantioselectivities, whereas that catalyzed by (S,S)-[RuCl(η6-hexamethylbenzene)diamine] give desirable chiral α-hydroxy esters through a slight adjustment of reaction conditions.
Enantioselective iron-catalysed O-H bond insertions
Zhu, Shou-Fei,Cai, Yan,Mao, Hong-Xiang,Xie, Jian-Hua,Zhou, Qi-Lin
experimental part, p. 546 - 551 (2010/10/04)
The ready availability, low price and environmentally benign character of iron mean that it is an ideal alternative to precious metals in catalysis. Recent growth in the number of iron-catalysed reactions reported reflects an increasing demand for sustainable chemistry. Only a limited number of chiral iron catalysts have been reported and these have, in general, proven less enantioselective than other transition-metal catalysts, thus limiting their appeal. Here, we report that iron complexes of spiro-bisoxazoline ligands are highly efficient catalysts for asymmetric O-H bond insertion reactions. These complexes catalyse insertions into the O-H bond of a wide variety of alcohols and even water, with exceptional enantioselectivities under mild reaction conditions. The selectivities surpass those obtained with other transition-metal catalysts. This study should inspire and encourage the use of iron instead of traditional precious metals in the development of greener catalysts for catalytic asymmetric synthesis.
