Multicomponent Reactions Based On Ketenimine Intermediates And Isocyanates

Highlighted as one of research frontier, multicomponent reactions (MCRs) were widely used in heterocyclic constructing, combinatorial chemistry and total synthesis of natural products. In this thesis, the generating methods of ketenimines and the multicomponent reactions they participated in were reviewed. Mainly attention was paid to the multicomponent reactions based on N-sulfonyl ketenimine intermediates, through which coumarins and quinazolinones can be furnished. Furthermore, A new multicomponent reaction involving electron-deficient terminal alkynes was studied. The results and details are shown below:1. The copper-catalyzed MCRs of terminal alkynes, sulfonyl azides and methyl3-(2-hydroxyphenyl) propiolate furnished iminocoumarins was developed. We checked about the diversity of substrates and obtained all of them with good to excellent yields. This method is concise, general, efficient, non-intermediate separated and atom-economic. And I hope that the method could have a bright future in organic synthesis.2. An efficient synthetic method for the synthesis of4(3H)-quinazolinones from azides, alkynes, o-iodoanilines, and carbon monoxide in a one-pot was developed. We checked about the diversity of substrates and obtained all of them with good to excellent yields. Only when the substrates with strong electron-withdrawing group were failed in this reaction. This method is general, efficient and non-intermediate separated.3. A one-pot three-component reaction of N-alkylimidazole, acetylenic ketones and isocyanates was developed. This method was efficient for the C2-carbonylation of N-alkylimidazole. Furthermore, this reaction was catalyst-free, atom-economic and general. In addition, a possible mechanism was provided.