Asymmetric Reduction of 2-Chloro-3-oxo Esters by Transfer Hydrogenation
作者:Jinjin Bai、Shifeng Miao、Yun Wu、Yawen Zhang
DOI:10.1002/cjoc.201180419
日期:2011.11
Asymmetric reduction of 2‐chloro‐3‐oxoesters was achieved by catalytic transfer hydrogenation using [RuCl2(p‐cymene)](S,S)‐TsDPEN as the chiral catalyst and HCOOH‐Et3N as the hydrogen source. Moderate to good yields (up to 85%) and good enantioselectivities (up to 98% ee) were obtained.
Highly Diastereoselective and Enantioselective Synthesis of α-Hydroxy β-Amino Acid Derivatives: Lewis Base Catalyzed Hydrosilylation of α-Acetoxy β-Enamino Esters
By design: A series of α‐acetoxy‐β‐enamino esters 1 were synthesized and then subjected to catalytic asymmetric hydrosilylation. In the presence of a chiral Lewisbase catalyst, the reactions proceeded smoothly to provide a wide range of chiral α‐acetoxy β‐amino acid derivatives in high yields with good diastereoselectivities and enantioselectivities.
Catalytic Enantioselective Fluorination of α-Chloro-β-keto Esters in the Presence of Chiral Nickel Complexes
作者:Seung Hee Kang、Dae Young Kim
DOI:10.1002/adsc.201000515
日期:2010.11.2
The catalyticenantioselective electrophilic fluorination promoted by chiralnickelcomplexes is described. The treatment of α-chloro-β-ketoesters with Selectfluor under mild reaction conditions afforded the corresponding fluorinated α-chloro-β-ketoesters with excellent enantioselectivities (up to 99% ee).