Aromatic amide-derived non-biaryl atropisomers as highly efficient ligands in silver-catalyzed asymmetric cycloaddition reactions.
The synthesis of a series of aromatic amide-derived non-biaryl atropisomers with a phosphine group and multiple stereogenic centers is reported. The novel phosphine ligands exhibit high diastereo- and enantioselectivities (up to >99:1 d.r., 95-99 % ee) as well as yields in the silver-catalyzed asymmetric [3+2] cycloaddition of aldiminoesters with nitroalkenes, which provides a highly enantioselective strategy for the synthesis of optically pure nitro-substituted pyrrolidines. In addition, the experimental results with regard to the carbon stereogenic center as well as the amide stereochemistry confirmed the potential of hemilabile atropisomers as chiral ligand in catalytic asymmetric [3+2] cycloaddition reaction.
Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Hangzhou Normal University, No 1378, Wenyi West Road, Science Park of HZNU, Hangzhou (P.R. China); State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou Institute of Chemical Physics (CAS) and University of the Chinese Academy of Sciences, Beijing (P.R. China).
Xing-Feng
XF
Bai
Tao
T
Song
Zheng
Z
Xu
Chun-Gu
CG
Xia
Wei-Sheng
WS
Huang
Li-Wen
LW
Xu
asymmetric catalysis; atropisomers; cycloaddition; phosphine ligands; silver