Cyclic BF(sub2) adducts of functionalized Fischer vinylcarbene complexes: Preparation and stereoselective Diels-Alder reactions with 2-amino 1,3-dienes

The synthesis of novel boroxyvinylcarbene complexes with a cyclic chelate structure has been undertaken. This fixes the s-cis conformation of the exocyclic carbon-carbon and carbon-chromium double bonds temporarily. The Diels-Alder type reactions of the boron difluoride complexes with 2-amino 1,3-dienes are described, as well as a Diels-Alder reaction with chiral 2-amino 1,3-dienes.