New Method For The Synthesis Of Furan And Oxazole Derivatives

Furan derivatives are widely used in various natural products and pharmaceutical molecules due to their unique structure and high biological activity.At the same time,furan rings are also important intermediate frameworks for the synthesis of high-value drugs and pesticide chemicals.As a broad-spectrum anti-inflammatory antibacterial agent,they have high curative effect in dysentery,cholera and other diseases.The polysubstituted oxazole compounds originally isolated from marine organisms have also been proven to have good antibacterial and anticancer activities,and they have very important application prospects in medicine and materials science.Therefore,the development of a new method for the efficient synthesis of furans and oxazoles has become a hot topic.In this paper,a series of 2,3,5-trisubstituted furan derivatives were synthesized through continuous acid-catalyzed Passerini/silver-catalyzed cyclization reactions;A series of 2,4,5-trisubstituted oxazole derivatives were synthesized by dehydration cyclization through the catalytic cycle of phosphine dihalides/oxyphosphines under reducing conditions.The detail was summarized as follows:1.A brief overview of the synthesis of polysubstituted furans and polysubstituted oxazole derivatives in recent years and a brief introduction to Passerini multi-component reactions and Phosphine-catalyzed reactions are as follows:2.Phosphorus-catalyzed Passerini reaction with a-alkynyl substituted cinnamaldehyde prepared from Sonogashira reaction as the aldehyde component,and then cyclization isomerization under silver trifluoromethanesulfonate(AgOTf)catalysis to obtain 2,3,5-trisubstituted furan derivatives.Following are the synthetic routes.#123.A series of 2,4,5-trisubstituted oxazole derivatives were prepared by cyclization isomerization using amido ketone esters 7 under tetramethyldihydrosilyl ether/Cu(OTf)2 reduction system and PPh3(catalytic amount)/CCl4/NEt3 dehydration conditions.The synthetic route is as follows:(?)...