N-heterocyclic Carbene Gold Complexes-catalyzed Three-component Tandem Diels-alder Reactions Of Enynals/Enynones With Alkene

The early gold systems bearing phosphine and phosphite ligands provided importanttransformations and served as useful mechanistic probes. People paid more and more attentionto the N-heterocyclic gold complexes for ites excellent catalytic effect. Based on synthesis ofdifferent kinds of NHC-containing gold(I) complexes effectively, this paper mainly focus onthe research and exploration of the catalytic reaction of the unsaturated hydrocarbons andheteroatomic compounds. This article is mainly divided into the following two parts:1) Research of N-heterocyclic gold complex catalytic alkynal/alkynone with olefinsIn order to synthesize propeller-like products, in this reaction, enynals/enynones, norbene,benzoquinone were reacted as raw material, and NHC-AuCl(I)/Selectfluor were added ascatalyst. Mechanically speaking, the catalytically active species,[AuIIIClF(NHC)]+wasgenerated in situ from the oxidation of [AuCl(NHC)] with Selectfluor. Then the reactionproceeded through tandem Diels-Alder reactions via trapping of the cyclic-o-QDM. For thosepropeller-like products containing1,4-benzoquinone moiety, a retro-Diels-Alder reactioncould occur smoothly in the refluxing xylene, forming the anthraquinone derivatives. What`smore, many natural products, such as key of Doxorubicin and Aklavinone skeleton, containsthese anthraquinone structures.2) Exploration of terminal acetylene catalysis carboheterofunctionalizationTo synthesize of heterocyclic structure compounds which commonly exist in organiccompounds, this section begins with phenyl boronic acid and terminal enamine in stable andefficient catalytic pathway. We would like to develop a new approach to the synthesis ofpyrrolidine, via N-heterocyclic carbene gold(I)-catalyzed intramolecular carbon aminationreactions from a wide variety of alkene substrates such as N-allyl amides and phenylboronic acid under mild conditions. However, finally we turn our interests into the halogenatedreaction of terminal enamine itself. After exploring, a simple and efficient catalytic NBS canbe used to generate brominated cyclization pyrrolidine products. Furthermore, reactionconditions, such as solvent, temperature, time, and other halogen source, were optimizedsystematically.