Intermolecular [2 + 2] Photocycloaddition of α,β-Unsaturated Sulfones: Catalyst-Free Reaction and Catalytic Variants
作者:Noah Jeremias、Lisa-Marie Mohr、Thorsten Bach
DOI:10.1021/acs.orglett.1c01794
日期:2021.8.6
2-Aryl-1-sulfonyl-substituted cyclobutanes were prepared in an intermolecular [2 + 2] photocycloaddition from various α,β-unsaturated sulfones and olefins upon irradiation at λ = 300 nm (26 examples, 60–99% yield). Lewisacids catalyzed the [2 + 2] photocycloaddition of 2-benzimidazolyl styryl sulfones. At short wavelengths, the latter substrates underwent C–S bond cleavage but AlBr3 (5 mol %) allowed