Method for preparing polysubstituted benzofuran-4-formic acid compound through ruthenium catalysis

Abstract

The invention belongs to the technical field of organic synthesis, and discloses a method for preparing a polysubstituted benzofuran-4-formic acid compound through ruthenium catalysis. An m-hydroxybenzoic acid compound, a diaryl alkyne compound, a ruthenium catalyst, an additive and a solvent are subjected to a heating reaction in an air or oxygen environment, and a reaction product is separated and purified, so that the polysubstituted benzofuran-4-formic acid compound is obtained. The ruthenium catalytic system used in the method has high catalytic activity, so that air or oxygen can be used as a green oxidant in the reaction, and toxic, dangerous or expensive oxidants are prevented from being used. The reaction raw materials are easy to obtain, the solvent amount is small, the solvent is insensitive to water, operation is easy, convenient and safe, the method can be well amplified to the gram-level scale, and industrialization is convenient to achieve. The reaction is taken as a key step, the natural product diptoindonesin G with biological activity can be conveniently synthesized, and the diptoindonesinG has a good application prospect.

Description

technical field [0001] The invention belongs to the technical field of organic synthesis, and in particular relates to a method for preparing polysubstituted benzofuran-4-carboxylic acid compounds by ruthenium catalysis. Background technique [0002] Multi-substituted benzofurans widely exist in natural products, bioactive molecules and drug molecules, and their efficient synthesis methods have broad application prospects [(a) Keylor M.H., Matsuura B.S., StephensonC.R.J.Chem.Rev.2015,115, 8976; (b) Heravi M.M., Zadsirjan V., Hamidi H., Amiri P.H.T. RSC Adv.2017, 7, 24470; (c) Miao, Y.-h.; Hu, Y.-h.; Yang, J .; Liu, T.; Sun, J.; Wang, X.-j. RSC Adv.2019, 9, 27510.]. Among them, 2,3-diarylbenzofuran is the core skeleton of a large class of biologically active natural products, and is also a key intermediate for the synthesis of these natural products and their analogs (Keylor M.H., Matsuura B.S., Stephenson C.R.J.Chem. Rev. 2015, 115, 8976). For example, diptoindonesin G ca...

AI Technical Summary

Problems solved by technology

However, the reported synthetic routes require multi-step reactions from complex raw materials and are not universally applicable. The efficient synthesis of multi-substituted benzofuran-4-carboxylic acids from simple and easy-to-obtain raw materials needs to be further developed

However, there is no report on the ruthenium-catalyzed reaction of phenolic compounds and alkynes to construct benzofuran rings

In addition, none of the above synthetic techniques are suitable for the synthesis of carboxybenzofuran

Images