Synthesis and application of macrocyclic binaphthyl ligands with extended chiral bias
摘要:
Two macrocyclic and one non-cyclic chiral diphosphine ligand containing a 2,2'-bridged binaphthyl unit were synthesized in six steps from (R)-2,2'-dimethoxy-1,1'-binaphthyl in overall yields of 25 and; 17%, respectively. The new ligands showed asymmetric inductions of up to 98% e.e. if used in palladium catalyzed allylic alkylation reactions. (C) 1998 Elsevier Science Ltd. All rights reserved.