Cyclization Of Hypertylene Amide And Difluoroalkylation Oxidation Of Olefin

Furan and difluoroalkyl(CF2)group represent key strucral motifs of a number of natural products and pharmaceutical agents exhibit a wide range of biological activities which has attracted widespread attention of scientists.Scientists have developed a large number of methods for the synthesis of furans,what's more,the development of novel methods for the synthesis of polysubstituted 2-aminofuran remains a great challenge.As we know,the oxidation reaction often requires an equivalent amount of oxidant,which causes many problems.It is of great significance to develop an oxidation process that does not require an additional oxidant.In this paper,remote oxidation was successfully achieved by intramolecular hydrogen migration.The main content of the thesis is described below.1.Palladium-catalyzed tandem cycloisomerization of homoallenyl amides with allyltrialkylsilanes.Homoallenyl amides was used,PdBr2 as catalyst,DDQ as additive,MnO2 as oxidant,acetonitrile as solvent,allyl silicon as allylation reagent,and 2-amino-5-homoallyl group was synthesized in one step.The reaction exclusively affords y-allylation products in good to excellent yields with broad substrate scope under exceptionally mild reaction conditions.It represents one of the rare examples of the Pd-catalyzed intermolecular Heck-type coupling of allytrialkylsilanes terminating by ?-silyl elimination,thus complementing to traditional allylation methods because of the excellent ?-selectivity.2.Remote oxidation reaction of alkenes difluoroalkylation.Using bromodifluoroalkyl compounds as radical reagents,inexpensive CuI as a catalyst,L1(4,4-di-tert-butyl pyridine)as a ligand,and DCE as a solvent,a difluoroalkyl-substituted carbonyl compound was synthesized in one step.Mechanism studies indicate that the reaction goes through the course of free radical difluoroalkylation of olefins.Copper salt not only acts as a single electron reduction reagent,but also serves as an oxidant for subsequent radical oxidation,which plays a key role in the reaction.It should be pointed out that traditional alcohol oxidation requires an equivalent or excessive amount of oxidant,while the reaction developed in this paper does not require the addition of an oxidant,demonstrating it is a more green and economical oxidation method.