Chiral-at-Metal Ruthenium Complexes with Guanidinobenzimidazole and Pentaphenylcyclopentadienyl Ligands: Synthesis, Resolution, and Preliminary Screening as Enantioselective Second Coordination Sphere Hydrogen Bond Donor Catalysts
作者:Tathagata Mukherjee、Subrata K. Ghosh、Taveechai Wititsuwannakul、Nattamai Bhuvanesh、John A. Gladysz
DOI:10.1021/acs.organomet.0c00073
日期:2020.4.27
HN═C(NHH′)NHC(NHR)═NR′) chelate complexes are accessed by treating (η5-C5Ph5)Ru(CO)2(Br) with Me3NO, GBI, and Ag+PF6–. Chromatographic workups give [(η5-C5Ph5)Ru(CO)(GBI)]+PF6– (2+PF6–, 70%; silica gel) or 2+BArf– (69%; alumina, then Na+BArf– (BArf– = B(3,5-C6H3(CF3)2)4–)). Treatment of 2+PF6– with K+t-BuO– deprotonates the GBI ligand to give the neutral species (η5-C5Ph5)Ru(CO)(GBI–H) (3; 73%). Complexes 2+PF6–
Pentaphenylcyclopentadienyl钌2- guanidinobenzimidazole(GBI = H Ñ = C(NHH')NHC(NHR)═ Ñ R')螯合配合物是通过处理(η访问5 -C 5博士5)的Ru(CO)2(BR)与我3 NO,GBI和Ag + PF 6 –。色谱workups得到[(η 5 -C 5博士5)的Ru(CO)(GBI)] + PF 6 - (2 + PF 6 -,70%;硅胶)或2 +巴˚F -(69%;氧化铝,然后是Na + BAr f –(BAr f – = B(3,5-C 6 H 3(CF 3)2)4 –))。的治疗2 + PF 6 -具有K +吨-BuO -去质子化的配体GBI,得到中性物种(η 5 -C 5博士5)的Ru(CO)(GBI -H)(3 ; 73%)。配合物2 + PF 6 –,2 + BArf –和3通过NMR,X射线