Modern metal-catalyzed and organocatalytic methods for synthesis of coumarin derivatives: a review

Coumarin is an important pharmaceutical structural motif, abundantly found in numerous commonly used drugs. Compounds containing this core show a broad spectrum of medicinal properties and biological activities. The increasing importance and wide usages of coumarin derivatives have drawn attention to its synthetic methods, among which metal-catalyzed and organocatalytic methods have proved the most effective. Several metal-catalyzed and/or organocatalytic synthetic strategies for coumarin have been investigated and reported in recent decades. This review focuses on more recent reports on catalysis methods for synthesizing coumarin and coumarin-like structures (including light-mediated methods and nano-catalysts), exploring the mechanistic aspects, simplicity, efficiency, repeatability, and other advantages and disadvantages of these methods.

(8-Hy-droxy-6-meth-oxy-1-oxo-1H-isochromen-3-yl)methyl formate: a supra-molecular framework

In the title compound, C12H10O6, an intra-molecular O-H⋯O hydrogen bond forms an S(6) ring motif. The mol-ecule is essentially planar with an r.m.s. deviation of 0.051 Å for all non-H atoms. In the crystal mol-ecules are linked by C-H⋯O hydrogen bonds and a C-H⋯π inter-action, forming a supra-molecular framework.