Synthesis and Application of Diphenyl Sulfide Linked Bis(imidazoline) Ligands: Dramatic Electronic Effect of Ligands on Catalytic Behavior
作者:Xian Du、Han Liu、Da-Ming Du
DOI:10.1002/ejoc.201001347
日期:2011.2
Diphenyl sulfide linked bis(imidazoline) ligands with electron-withdrawing N-Ts substitution and electron-donating N-alkyl or N-H substitutions were synthesized through different routes. The electronic effects of the ligands were tuned rationally, and dramatic variation in their catalytic behavior was observed. N-Alkyl and N-H ligands demonstrated much higher catalytic activity and improved enantioselectivity