96612-29-2

Upstream product

• 109-99-9 tetrahydrofuran 
• 3806-59-5 1,3-cyclooctadiene 
• 3806-60-8 (1E,3Z)-1,3-cyclooctadiene 

Relevant academic research and scientific papers

Enantiodifferentiating photoisomerization of (Z, Z)-1,3-cyclooctadiene included and sensitized by naphthoyl-curdlan

6-O-(2-Naphthoyl)curdlan was newly synthesized as a sensitizing polysaccharide host to examine the chiroptical properties, supramolecular complexation, and photochirogenic behavior with (Z,Z)-1,3-cyclooctadiene (1ZZ). The enantiodifferentiating photoisomerization of 1ZZ included and sensitized by this polysaccharide host gave a highly strained chiral (E,Z)-isomer in up to 8.7% enantiomeric excess (ee) in solution and 11.7% ee in the solid state, which are the highest values ever reported for a supramolecular photochirogenesis of 1EZ.

Enantiodifferentiation in the Photoisomerization of (Z,Z)-1,3-Cyclooctadiene in the Cavity of γ-Cyclodextrin-Curcubit[6]uril-Wheeled [4]Rotaxanes with an Encapsulated Photosensitizer

A biphenyl photosensitizer axle was implanted into the cavities of native and capped γ-cyclodextrins through rotaxanation using a cucubit[6]uril-templated azide-alkyne 1,3-dipolar cycloaddition, resulting in the construction of highly defined chiral binding/sensitizing sites. The orientation and interaction of the axle and capping moieties at the ground and excited states were interrogated by NMR, UV-vis, circular dichroism, and fluorescence spectroscopic studies. In situ photoisomerization of (Z,Z)-1,3-cyclooctadiene sensitized in the cavity of these [4]rotaxanes afforded (Z,E)-1,3-cyclooctadiene in up to 15.3% ee, which represents the highest level of enantiodifferentiation obtained to date for this supramolecular photochirogenesis.

Optically active (E,Z)-1,3-cyclooctadiene: First enantioselective synthesis through asymmetric photosensitization and chiroptical property

Enantiodifferentiating photoisomerizations of (Z,Z)-1,3-cyclooctadiene (1ZZ) to the chiral E,Z-isomer 1EZ were performed at varying temperatures in the presence of some benzenepoly-, naphthalene(di)-, and anthracenecarboxylates. Of these chiral sensitizers, (-)-menthyl benzenehexacarboxylate afforded the highest enantiomeric excesses (ee's) up to 10% and 18% in pentane at 25 and -40°C, respectively. In contrast, the use of polar solvents greatly diminished the product's ee, suggesting intervention of a radical ionic rather than exciplex intermediate in these solvents. Optically pure 1EZ is shown to possess anomalously high specific rotation and circular dichroism as a simple diene chromophore: [α]25(D) 1380°(CH2Cl2), Δε 12.8 M-1 cm-1 (λ(ext) 228 nm, cyclohexane). The chiroptical properties observed not only correct the previous data but also present the conclusive evidence for the recent theoretical predictions.

Investigation of Rearrangement Reactions of Cyclic Allyl and Pentadienyl Anions

Bicyclohexenyl anion (1) and bicycloheptenyl anion (2) rearrange in THF to monocyclic pentadienyl anions, whereas bicyclooctenyl anion 3 is stable under the reaction conditions. 3 in contrary is formed by the known electrocyclic ring closure of cyclooctadienyl anion 7.Rearrangements of cyclopentenyl anion and pentadienyl anion are not detected.Cyclic allyl anions are alkylated by ethene, formed by cleavage of THF with base or independently added. 6,6-Dimethylcyclohexadienyl anion undergoes slow fragmentation to toluene at room temperature.