An efficient synthesis of 4-substituted coumarin derivatives via a palladium-catalyzed Suzuki cross-coupling reaction

作者：Rajale Trideep; Sharma Shikha; Stroud Daniel A; Unruh Daniel K; Miaou Emily; Lai Kimberly; Birney David M^*

来源：Tetrahedron Letters, 2014, 55(49): 6627-6630.

DOI：10.1016/j.tetlet.2014.10.078

• Suzuki cross-coupling
• Organotrifluoroborates
• Coumarins
• Atropisomerism

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-viny1-2H-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-methoxypheny1)-2H-chromen-2-one (1d), are evidence of the steric crowding in these adducts.

• 出版日期2014-12-3