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 Novel multi-dentate phosphines for Pd-catalyzed alkoxycarbonylation of alkynes promoted by H2O additive, published in 2019-03-31, which mentions a compound: 3393-45-1, Name is 5,6-Dihydro-2H-pyran-2-one, Molecular C5H6O2, Application In Synthesis of 5,6-Dihydro-2H-pyran-2-one.
A series of novel multi (bi-/tri-/tetra-)-dentate phosphines with good robustness against water and oxygen were synthesized and fully characterized. It was found that the developed ionic tri-dentate phosphine enabled Pd-catalyzed alkoxycarbonylation of alkynes with CO and alcs. which gave α,β-unsaturated esters RCH=CHCO2R1 [R = n-Bu, Ph, Bn, etc.; R1 = Me, Et, i-Pr, C6H11] and I using H2O as an additive instead of acid. As for ionic tri-dentate phosphine, its unique steric configuration with two types of potential P-P chelation modes (P···P distance of 4.31 Å and 4.36 Å resp.) to Pd-center rendered the corresponding Pd-catalyst high activity and good stability for alkoxycarbonylation of alkynes. The in situ FT-IR anal. also verified that the formation and stability of Pd-H active species were greatly facilitated with the presence of ionic tri-dentate phosphine as well as H2O additive. In addition, as an ionic phosphine, ionic tri-dentate phosphine based PdCl2(MeCN)2 system immobilized in RTIL of [Bmim]NTf2 could be recycled for 7 runs without obvious activity loss or metal leaching.
Here is a brief introduction to this compound(3393-45-1)Application In Synthesis of 5,6-Dihydro-2H-pyran-2-one, if you want to know about other compounds related to this compound(3393-45-1), you can read my other articles.
Reference:
Metal catalyst and ligand design,
Ligand Template Strategies for Catalyst Encapsulation – NCBI