Combining engineering and chemistry for the selective continuous production of four different oxygenated compounds by photo-oxidation of cyclopentadiene using liquid and supercritical CO2 as solvents. Issue 25 (21st June 2018)

• Record Type: Journal Article
• Authors: Wu, Lingqiao; Abada, Zahra; Lee, Darren S.; Poliakoff, Martyn; George, Michael W.
• Is Part Of: Tetrahedron. Volume 74:Issue 25(2018)
• Page Start: 3107
• Page End: 3112
• Publication Date: 2018-06-21
• Subjects: Photo-oxidation -- Photochemistry -- Cyclopentadiene -- Singlet oxygen -- Supercritical CO2 -- Liquid CO2 -- Continuous flow -- Flow chemistry; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2017.11.048
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: A range of products is reported from the photo-oxidation of cyclopentadiene from photochemically generated singlet oxygen ( 1 O2 ) using carbon dioxide (CO2 ) as a solvent and 5, 10, 15, 20-tetrakis-(pentafluorophenyl)porphyrin (TPFPP) as a CO2 -soluble photosensitizer. The endo-peroxide intermediate, generated from the reaction with singlet oxygen, is transformed into one of several different products in good yield depending on the conditions applied and by adding different reactors and reagents downstream of the photo-reactor, allowing the reaction products to be switched in one streamlined process. The addition of a thermal reactor facilitated the rearrangement of the endoperoxide to form Z -4, 5-epoxy-2-pentanal. Quenching with thiourea yielded the syn -diol, (1 R, 3 S )-cyclopent-4-ene-1, 3-diol. Treatment with acid or base afforded furfuryl alcohol and 4-hydroxy-2-cyclopentenone respectively. High productivities for all products were obtained when compared to traditional batch reactions. Graphical abstract: Image 1