Preparation of Amino Acid-Bridged Dicatechol Ligands for Dinuclear Titanium(IV) Complexes
作者:Markus Albrecht、Rainer Nolting、Patrick Weis
DOI:10.1055/s-2005-861865
日期:——
acid-bridged dicatechol ligands 2a-e-H 4 were prepared by peptide coupling reactions. Under special conditions, an unusual BBr 3 -promoted amide to methyl ester transformation was observed for the asparagine and glutamine side chain functions. The ligands were used in coordination studies with titanium(IV) ions in the presence of an alkali metal carbonate. Double-stranded complexes Li 2 [(2a-e) 2 (OR) 2 Ti
通过肽偶联反应制备氨基酸桥连联苯二酚配体2a-eH 4。在特殊条件下,对于天冬酰胺和谷氨酰胺侧链功能,观察到不寻常的 BBr 3 促进的酰胺到甲酯的转化。在碱金属碳酸盐的存在下,配体用于与钛 (IV) 离子的配位研究。双链复合物 Li 2 [(2a-e) 2 (OR) 2 Ti 2 ] 与锂抗衡阳离子选择性地形成具有桥接金属的醇化配体 (R = CH 3 、C 2 H 5 、C 3 H 5 ) . 另一方面,除了双链M 2 [(2b,c,e) 2 (OCH 3) 2 Ti 2 ] (M = Na, K)。