Structure-dependent regioselectivity of a roll-over cyclopalladation occuring at 2,2′-bipyridine-type ligands
作者:Yanik Becker、Florian Schön、Sabine Becker、Yu Sun、Werner R. Thiel
DOI:10.1016/j.jorganchem.2021.121780
日期:2021.5
In this work, different bipyridine-analogue ligands bearing a dimethylamino group in the meta-position of one of the heterocyclic rings were synthesized and reacted with palladium(II) acetate under identical conditions. Cyclometallated palladium(II) complexes with C,N- or C,N,N’-coordinating chelate ligands are formed which were characterized by elemental analysis, 1H and 13C NMR spectroscopy, and
在这项工作中,合成了在一个杂环的间位上带有二甲氨基的不同联吡啶-类似物配体,并在相同条件下与乙酸钯(II)反应。形成具有C,N-或C,N,N '配位螯合配体的环金属化钯(II)配合物,通过元素分析,1 H和13 C NMR光谱以及单晶X射线衍射分析对其进行表征。在单核的情况下,C,N,N通过配位N-甲基上的钯(II)位点形成的配位配合物,主要配位的乙酰基配体被交换成氯代配体,后者通过亲核取代反应从溶剂二氯甲烷中释放出来。相比之下,发生在六元杂环之一的环金属化反应会导致双核乙酰桥联钯(II)配合物。