Palladium/Acid Relay Catalyzed Tandem Heck Coupling/6‐Endo Cyclization between ortho‐Halogenated Benzoates and Unactivated Terminal Alkenes for the Synthesis of 1‐Isochromanones
We report a unique and expeditiousroute to synthesize 1‐isochromanone derivatives through palladium catalyzed tandem Heck coupling/6‐endo hydroacyloxylation cyclization between readily available ortho‐halogenated benzoates and unactivated alkenes. Various 2‐bromo or 2‐iodo benzoates can be coupled efficiently with a broad range of alkenes to afford functionalized 1‐isochromanones in high yields. Significantly
Synthesis, Structure and Properties of Fused π‐Extended Acridone Derivatives
作者:Hongshuai Gao、Gang Zhang
DOI:10.1002/ejoc.202000871
日期:2020.9.7
The angularly and linearly fused acridone derivatives were synthesized and their properties were shape‐depended. The angularly fused acridone derivatives showed weakened aromaticity of the benzene ring at the turning point, whereas the linearly fused ones demonstrated stronger fluorescence intensity and better electronic couplings with potential applications in organic electronics.
The practical use of 2,2-dimethyl-2H-pyrans as electron-rich dienes in sequential Diels–Alder/retro-Diels–Alder (DA/rDA) domino processes to generate aromatic platforms has been demonstrated. Different polysubstituted alkyl 2-naphthoates have been synthesized by the DA/rDA reaction of benzynes and 2,2-dimethyl-2H-pyrans. The use of other activated alkynes allows the access of substituted alkyl benzoate
Specific deuterium labelling, combined with 13C-NMR spectroscopy, has been used to study the course of the photocyclodehydrogenetions leading to hexa-, hepta-, octa- and nonahelicene. The case of heptahelicene is a good illustration of the scope and limitations of this technique in this particular field.