Easy and regioselective synthesis of highly functionalized o-quinodimethide precursors from Fischer carbene complexes and isocyanides.
Highly functionalized cis- and trans-1,2-bis(trialkylsilyloxy)benzocyclobutene derivatives have been synthesized in a completely regioselective fashion from easily available Fischer alkenylcyclobutenyl(alkoxy)carbene complexes and isocyanides. This methodology can be viewed as an alternative to existing methods of synthesis of this kind of compounds and overcomes the main problem of introducing functionality in the aromatic ring. Both cis and trans derivatives underwent the expected fragmentation to generate o-quinodimethide intermediates upon thermal treatment, affording complex polycyclic structures in a stereoselective manner when heating was carried out in the presence of a range of electron deficient dienophiles.
Barluenga
José
J
Instituto Universitario de Química Organometálica, Enrique Moles Unidad Asociada al C.S.I.C., Julián Clavería 8 33071 Oviedo, Spain. barluenga@sauron.quimia.uniovi.es
Aznar
Fernando
F
Palomero
M Angel
MA