Winterling, Erik; Ivlev, Sergei; Meggers, Eric published their research in Organometallics in 2021. The article was titled 《Chiral-at-Ruthenium Catalysts with Mixed Normal and Abnormal N-Heterocyclic Carbene Ligands》.SDS of cas: 624-28-2 The article contains the following contents:
We recently reported a new class of chiral ruthenium catalysts in which two achiral bidentate N-(2-pyridyl)-substituted N-heterocyclic carbene ligands in addition to two labile acetonitriles are coordinated to a central ruthenium and generate a stereogenic metal center which is responsible for the overall chirality. Here we now report our discovery of related chiral-at-ruthenium catalysts in which normal and abnormal N-heterocyclic carbene (NHC) ligands are present at the same time. The synthesis of racemic complexes, their resolution into individual enantiomers by a chiral auxiliary approach, and a catalytic application are reported. The mixed normal/abnormal NHC complexes display significantly increased turnover numbers and turnover frequencies for a nitrene-mediated enantioselective C(sp3)-H amination. In the experiment, the researchers used 2,5-Dibromopyridine(cas: 624-28-2SDS of cas: 624-28-2)
2,5-Dibromopyridine(cas: 624-28-2) belongs to pyridine. Pyridine is very deactivated towards electrophilic substitution with respect to benzene. For this reason classical formylation, using methods such as the Gattermann or Vilsmeier reactions, are not generally successful. SDS of cas: 624-28-2