Abstract
An efficient Pd-catalyzed Suzuki cross-coupling reaction of sterically crowded 4-chlorocoumarin derivatives with air- and moisture-stable potassium organotrifluoroborates is developed. This methodology has been used to generate a series of novel alkyl, aryl, and vinyl substituted coumarin derivatives in good to excellent yields. The twisted conformation of the vinyl groups in the X-ray crystal structures of (2-oxo-4-vinyl-2H-chromen-3-yl)methyl acetate (2) and (2-oxo-4-vinyl-2H-chromen-3-yl)methyl 2,2,2-trichloroacetimidate (3), along with the atropisomerism of 3-(hydroxymethyl)-4-(2-methoxyphenyl)-2H-chromen-2-one (1d), are evidence of the steric crowding in these adducts.
Original language | English |
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Pages (from-to) | 6627-6630 |
Number of pages | 4 |
Journal | Tetrahedron Letters |
Volume | 55 |
Issue number | 49 |
DOIs | |
State | Published - Dec 3 2014 |
Keywords
- Atropisomerism
- Coumarins
- Organotrifluoroborates
- Suzuki cross-coupling