Studies On Tandem Electrophilic Cyclization Of Propargyl And Indoles Alcohols

Tandem reactions have been highlighted as one of research frontier, and widely used for the construction of heterocycles and total synthesis. In this thesis, acid controlled tandem cyclization reactions between propargyl alcohols and indoles were investigated.3,4-Dihydrocyclopenta[6]indoles, and2-iodo-1,4-dihydrocyclopenta[b] indoles, and1,3-dihydrobenzo[cd]indole were effectively constructed in moderate to good yields. Results were listed as following:1. In the presence of triflic acid,3-alkenylation of indole occurred in the reaction between propargylic alcohols and indoles which led to the formation of3,4-dihydrocyclopenta[b] indoles via a cascade process. As a comparison, in the presence of Cu(OTf)2,3-alkylation of indole resulted in the formation of3-propargylic indoles which were subsequently converted into2-iodo-1,4-dihydro-cyclopenta[b]indoles with the aid of N-iodosuccinimide and boron trifluoride etherate.2. Lewis acid catalyzed reactions between propargylic clcohols and electron-rich aromatic systems, such as acetyl aniline, triphenylamine, N-butyl carbazole, and1-acetoxy-1,3-butadiene were also investigated in detail. A series of fused heterocycles were constructed.