Unconventional stereoselective one-pot synthesis of Knoevenageltype indoles via in situ condensation of iminium salts with active methylene reagents

作者：Ranise Angelo; Lucchesini Francesco; Caviglia Matteo; Alfei Silvana; Spallarossa Andrea^*; Caneva Chiara

来源：Tetrahedron, 2013, 69(51): 10858-10868.

DOI：10.1016/j.tet.2013.10.086

• Active methylene reagents
• Iminium salts
• Knoevenagel reaction
• Nucleophilic addition
• E2 anti elimination

A simple one-pot procedure for the stereoselective synthesis of Knoevenagel-type indoles is described. The method is based on the in situ reaction of indole iminium salts (four of them are fully characterized) with acyclic symmetrical and unsymmetrical active methylene reagents in the presence of triethylamine. In general, the overall yields are moderate to good. Some of relevant reaction parameters and steric effects affecting stereoselectivity are discussed.

• 出版日期2013-12-23