Novel α,β-unsaturated lactams are synthesised on the basis of cyclic imines that have long been established in the working group. The valerolactams are prepared by ruthenium-catalysed ring closure metathesis (RCM) from dienes, which are accessible by acid chloride addition to the imines.

The α,β-unsaturated oxa-, aza- and seleno-lactams are the first representatives of these new lactam classes described in the literature. Only the α,β-unsaturated δ-thiacaprolactams have been previously described in the literature.

New valerolactam structures were also obtained by a similar synthetic route. This involved a HOSOMI-SAKURAI reaction as an intermediate step after the acid chloride addition in order to obtain dienes from the acrylamides. Subsequently, a ring-closing metathesis was also carried out here.

The lactam structures obtained in this way are good MICHAEL acceptors due to their conjugated double bond.

Selected publications

M. Watzke, K. Schulz, K. Johannes, P. Ullrich, J. Martens: First Synthesis of Bi- and Tricyclic α,β-Unsaturatedδ-Oxacaprolactams from Cyclic Imines via Ring-Closing Metathesis, Eur. J. Org. Chem. 2008, 3859-386. (DOI:10.1002/ejoc.200800254)

K. Schulz, M. Watzke, K. Johannes, P. Ullrich, J. Martens: Synthesis of Bi- and Tricyclic α,β-Unsaturated Lactams as Potential Michael Acceptors Starting from Heterocyclic Imines, Synthesis 2009, 665-673. (DOI:10.1055/s-0028-1083342)

K. Johannes, M. Watzke, J. Martens: Synthesis of α,β-Unsaturated Caprolactams Starting from Heterocyclic Imines, J. Heterocyclic Chem. 2010, 47, 697-702. (DOI:10.1002/jhet.381)