A Tripod Ligand with Three Different "Legs" and Some Chiral Zinc Complexes Thereof
摘要:
Stepwise alkylation of 2-picolylamine has yielded the unsymmetrical tripodal amine ligand (2-picolyl)(N-pyrrolidinylethyl)(2-hydroxy-3,5-di-tert-butylbenzyl) (L). In the presence of diethylzinc, L is deprotonated at the phenolic OH function with formation of the unstable complex L . Zn-Et (1). 1 can be used as an intermediate for the synthesis of chiral L . Zn-X complexes by protolysis. Thus, with 2,4-dibromophenol, L . Zn-OC6H3Br2 (2) is obtained, and with diphenylphosphoric acid, L . Zn-OPO(OPh)(2) (3) is formed. The low symmetry of the ligand L allows detailed NMR assignments. Complex 2 was subjected to a crystal structure determination