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
Facile synthesis of chiral 2-amino-4-(indol-3-yl)-4H-chromene derivatives using thiourea as the catalyst
作者:Yu Gao、Da-Ming Du
DOI:10.1016/j.tetasy.2013.08.018
日期:2013.10
The enantioselective Friedel-Crafts alkylation of indoles with iminochromenes catalyzed by a bifunctional thiourea organocatalyst was investigated. This reaction afforded chiral functionalized 2-amino-4-(indol-3-yl)-4H-chromenes in good yields (up to 87% yield) and with moderate to good enantioselectivities (up to 86% ee). (C) 2013 Elsevier Ltd. All rights reserved.