Details

Autor(en) / Beteiligte

• Murray, Philip R. D
• Bussink, Willem M. M
• Davies, Geraint H. M
• van der Mei, Farid W
• Antropow, Alyssa H
• Edwards, Jacob T
• D’Agostino, Laura Akullian
• Ellis, J. Michael
• Hamann, Lawrence G
• Romanov-Michailidis, Fedor
• Knowles, Robert R

Titel

Intermolecular Crossed [2 + 2] Cycloaddition Promoted by Visible-Light Triplet Photosensitization: Expedient Access to Polysubstituted 2‑Oxaspiro[3.3]heptanes

Ist Teil von

• Journal of the American Chemical Society, 2021-03, Vol.143 (10), p.4055-4063

Ort / Verlag

United States: American Chemical Society

Erscheinungsjahr

2021

Link zum Volltext

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• This paper describes an intermolecular cross-selective [2 + 2] photocycloaddition reaction of exocyclic arylidene oxetanes, azetidines, and cyclobutanes with simple electron-deficient alkenes. The reaction takes place under mild conditions using a commercially available Ir­(III) photosensitizer upon blue light irradiation. This transformation provides access to a range of polysubstituted 2-oxaspiro[3.3]­heptane, 2-azaspiro[3.3]­heptane, and spiro[3.3]­heptane motifs, which are of prime interest in medicinal chemistry as gem-dimethyl and carbonyl bioisosteres. A variety of further transformations of the initial cycloadducts are demonstrated to highlight the versatility of the products and enable selective access to either of a syn- or an anti-diastereoisomer through kinetic or thermodynamic epimerization, respectively. Mechanistic experiments and DFT calculations suggest that this reaction proceeds through a sensitized energy transfer pathway.