One-pot stereoselective synthesis of dimethanodibenzo[e,i][1,4]diazecines by a zinc-acetic acid promoted cascade reaction

The title compounds interesting C-2 symmetrical diamines. They were prepare d in a one-pot process by reacting quinaldines with a zinc-acetic acid mixt ure in THF solution. During this simple and stereoselective process, two C- C bonds and 4 stereogenic centres are created under mild conditions. Influe nce of the concentration of reagents upon yields and intramolecular cycliza tion regiochemistry is demonstrated. Experiments using deuteriated acetic a cid allowed a good understanding of these results. (C) 1999 Elsevier Scienc e Ltd. All rights reserved.