Heterogeneous platinum catalytic aerobic oxidation of cyclopentane-1,2-diols to cyclopentane-1,2-diones

DFT Study To Explore the Importance of Ring Size and Effect of Solvents on the Keto–Enol Tautomerization Process of α- and β-Cyclodiones

“…17,61,62 The aerobic oxidation of cyclopentane-1,2-diols to the corresponding diketones over a commercial heterogeneous Pt/C catalyst was studied previously. 63 Tautomerization of 1,2-cyclohexanedione has also been examined computationally and experimentally. 64−66 There are also reports on direct α-alkylation of 1,2-cyclohexanedione and its enolization, which occurs via its dianionic form.…”

“…Furthermore, α-cyclodiones and β-cyclodiones have been extensively studied because of their use in organic chemistry and also because they are well studied by crystallographers. − ,,− The presence of cyclic-α-diketones and cyclic-β-diketones in various crystals results in significant optical, electrical, and magnetic properties of the respective crystals. Not only these compounds exhibit substantial applications in the optical field as a fluorescence probe and laser material, but also their keto–enol tautomerization process has a significant role in various chemical reactions. ,, The aerobic oxidation of cyclopentane-1,2-diols to the corresponding diketones over a commercial heterogeneous Pt/C catalyst was studied previously . Tautomerization of 1,2-cyclohexanedione has also been examined computationally and experimentally. − There are also reports on direct α-alkylation of 1,2-cyclohexanedione and its enolization, which occurs via its dianionic form. , Keto–enol tautomerization of cyclic-α-diketones and cyclic-β-diketones has been studied by many research groups; however, the effects of ring size on the keto–enol tautomerization process and the role of solvents on such systems have not been explored in the literature.…”

Carbohydrate‐Derived 3,2‐Enolones in the Base‐Catalyzed Rearrangement to Highly Functionalized C4‐Quaternary 4‐Hydroxy‐2‐cyclopentenones

“…The carbonyl bond length (C1–O1 1.208 Å), carbonyl angles (O1–C1–C2 127.5, O1–C1–C5 127.0, C2–C1–C5 105.4°) and the alkene bond length (C2–C3 1.337 Å) were found to be in the expected range. Both the torsion angle involving the α,β‐unsaturated carbonyl system (O1–C1–C2–C3 167.4°) and involving the C 4 and C 5 carbon atoms (O1–C1–C5–C4 –157.1°) showed a substantially higher deviation from the expected values when compared to structurally similar C 5‐unsubstituted compounds published in the literature . Such distortions can be rationalized by steric crowdedness resulting from the high functionalization of the compound.…”

“…Both the torsion angle involving the α, -unsaturated carbonyl system (O1-C1-C2-C3 167.4°) and involving the C4 and C5 carbon atoms (O1-C1-C5-C4 -157.1°) showed a substantially higher deviation from the expected values when compared to structurally similar C5-unsubstituted compounds published in the literature. [18] Such distortions can be rationalized by steric crowdedness resulting from the high functionalization of the compound.…”