In general, if the atoms that make up the ring contain heteroatoms, such rings become heterocycles, and organic compounds containing heterocycles are called heterocyclic compounds. An article called Delineating Origins of Stereocontrol in Asymmetric Pd-Catalyzed α-Hydroxylation of 1,3-Ketoesters, published in 2010-05-07, which mentions a compound: 221012-82-4, Name is (R)-2,2′,6,6′-Tetramethoxy-4,4′-bis(diphenylphosphino)-3,3′-bipyridine, Molecular C38H34N2O4P2, Name: (R)-2,2′,6,6′-Tetramethoxy-4,4′-bis(diphenylphosphino)-3,3′-bipyridine.
Systematic studies of reaction conditions and subsequent optimization led to the identification of important parameters for stereoselectivity in the asym. α-hydroxylation reaction of 1,3-ketoesters. Enantioselectivities of up to 98% can be achieved for cyclic substrates and 88% for acyclic ketoesters. Subsequently, the combination of cyclic/acyclic ketoester, catalyst, and oxidant was found to have a profound effect on reaction rates and turnover-limiting steps. The stereochem. of the reaction contradicts that observed for other similar electrophilic substitution reactions. This was rationalized by transition-state modeling, which revealed a number of cooperative weak interactions between oxidant, ligand, and counterion, together with C-H/π interactions that cumulatively account for the unusual stereoselectivity.
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Reference:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider