Study On The Synthesis Of Isoindolines,Isoxazoles,Dihydropyrazoles Compounds Starting From Unsaturated Hydrocarbon

In recent years,substance transformation about the unsaturated hydrocarbon has been the forefront and core of scientific research.Unsaturated hydrocarbon are important staple product of petroleum and petrochemical industries.And it is also significant precursors in organic synthesis.In scientific point of view,the functionalization of unsaturated hydrocarbon is of great importance due to promoting the advancement of human material civilization and its core position in scientific development.The research around the substances conversion reactions of unsaturated hydrocarbon is the source and power of chemistry development.Simultaneously,it provides advanced methods and techniques for chemical products,pharmaceuticals,agricultural chemicals,materials and other functional molecules.Present,the research focus in this field is efficient conversion reaction with unsaturated hydrocarbons in keeping with atom economy and environment-friendly.In this context,we reported the synthesis of isoindolines,isoxazoles,dihydropyrazoles compounds starting from unsaturated hydrocarbon.(1)A highly regioselective synthesis of isoindoline fused with triazoles and substituted isoindolines from bromo chalcones and sodium azide based on reaction conditions selection is reported.In the presence of no catalyst,reaction of bromo chalcones with sodium azide in DMF at room temperature afforded isoindoline fused with triazoles in good to excellent yields.Whereas treatment of bromo chalcones with sodium azide under nitrogen at 10? for 3 h then rise to 60? for 1 h selectively produced substituted isoindolines in moderate yields.Good yields,high regioselectivity,easily available starting materials and simple operation make it an attractive alternative to the contemporary synthetic routes.(2)A novel TEMPO-catalyzed reaction to synthesize 5-substituted isoxazoles from propargylic ketones and TMSN3 has been disclosed.This reaction provides mild conditions to afford a variety of useful 5-substituted isoxazoles by metal-free catalysis in an efficient and regioselective manner.The method can be used for the preparation of industrially and pharmaceutically important N-and O-containing motifs,directly from simple and readily available substrates.(3)An efficient and straightforward one-pot strategy for the synthesis of 4,5-dihydropyrazole derivatives from ketones,arylacetylenes and hydrazines in the presence of KO'Bu/DMSO is described.This strategy provides a flexible andrapid route to polysubstituted 4,5-dihydropyrazoles.