Synthesis Of Tetrahydroquinolines And Chiral Exocyclic Allylic Alcohols Based On Transfer Hydrogenation Stategy

Tetrahydroquinolines and chiral cyclic allyl alcohols are the key frameworks of many natural products and drug molecules.It is of great scientific significance and application prospects to study the green synthesis methods of these compounds.At present,the reported synthesis of tetrahydroquinolines by transfer hydrogenation using chiral phosphoric acid as catalyst which is complex and expensive.Asymmetric hydrogenation synthesis of chiral cyclic allyl alcohols using transition metal complexes with chiral phosphine ligands which are expensive and sensitive to air and water.The reaction conditions are harsh and require special equipments such as autoclaves.Based on the concept of green chemistry,we have developed a new method of transfer hydrogenation for the synthesis of tetrahydroquinolines by iron-catalyzed and chiral cyclic allyl alcohols by ruthenium-catalyzed.(1)Biomimetic transfer hydrogenation of tetrahydroquinoline compounds by iron-catalyzed:A series of tetrahydroquinoline compounds were synthesized by biomimetic transfer hydrogenation under mild conditions using cheap and low toxic iron salts as catalysts and Hantzsch ester as hydrogen source without adding other ligands.(2)Asymmetric transfer hydrogenation of chiral cyclic allyl alcohols by ruthenium-catalyzed:Chiral cyclic allyl alcohols were first synthesized by asymmetric transfer hydrogenation using ruthenium complexes with chiral diamine ligands as catalysts which are cheap,relatively stable to air and water,and formic acid/triethylamine mixture as hydrogen source.Chiral cyclic allyl alcohols can up to 99% ee.This method has been successfully applied to the synthesis of key chiral intermediate of natural product Goniomitine.