The catalytic dearomatization of pyridines, accessing medicinally relevant N-heterocycles, is of high interest. Currently direct, dearomative strategies rely generally on reduction or nucleophilic addition, thus limiting the architecture of the dearomatized products to a six-membered ring. We herein introduce a catalytic, dearomative cycloaddition reaction with pyridines using photoinduced energy transfer
Ru(MC33)(CO)2(H2O) was obtained in yields of up to 97% using a pincer-type ligand containing the bis(carboxamide) moiety and ruthenium(0) carbonyl precursor. Ru(AC)(CO)2(H2O) having a pincer-type acyclic ligand AC was also synthesized in a similar manner to Ru(MC33)(CO)2(H2O). Mono(phosphine) and bis(phosphite) complexes were formed via the selective thermal ligand exchange of CO with phosphorus ligands
钌配合物 Ru( MC33 )(CO) n (L) 2− n (L = H 2 O, PPh 3 , P(OEt) 3 ; n = 1, 2) 与带有空腔的钳型大环配体MC33是合成和表征。使用含有双(甲酰胺)部分和钌(0)羰基前体的钳型配体,以高达 97% 的产率获得Ru( MC33 )(CO) 2 (H 2 O)。的Ru(AC)(CO)2(H 2 O)具有钳型无环配位体AC也以类似的方式合成的Ru(MC33 )(CO) 2 (H 2 O)。单(膦)和双(亚磷酸酯)配合物是通过CO 与磷配体的选择性热配体交换形成的。通过核磁共振光谱、红外光谱、电喷雾电离-高分辨率质谱和 X 射线分析研究了配合物的结构。此外,还证明了它们对氢化硅烷化的催化活性。
Towards phosphine-free Pd(II) pincer complexes for catalyzing Suzuki-Miyaura cross-coupling reaction in aqueous medium
作者:Peter Jerome、Pushpanathan N. Sathishkumar、Nattamai S.P. Bhuvanesh、Ramasamy Karvembu
DOI:10.1016/j.jorganchem.2017.03.045
日期:2017.9
analytical, spectroscopic (FT-IR, UV-Visible, 1H, 13C & 31P NMR and Mass) and single crystal X-ray diffraction techniques. Single crystal X-ray analysis reveals a distorted square planar geometry around Pd in all the complexes. These pincer complexes have been used as catalysts in Suzuki-Miyaura cross-coupling reaction. The effect of ancillary ligands (CH3CN and PPh3) in the complexes has been investigated