Abstract
The chromium-templated [3+2+1]-benzannulation of dibenzofuryl(methoxy)carbene complex 1 with alkynes leads to hydroquinoid benzonaphthofurans. A competition of angular versus linear annulation affords angular-fused (η 6-1,2,3,4,4a,11c)-benzo[ b]naphtho[1,2- d]furan tricarbonyl chromium complexes 2– 6 along with considerable amounts of uncoordinated benzo[ b]naphtho[2,3- d]furans as linear annulation products 7– 9. As demonstrated for 2 and 6 the Cr(CO) 3 complexes undergo a thermally induced haptotropic metal migration along the tetracyclic heteroaromatic π-system to give (η 6-7a,8,9,10,11,11a)-benzonaphthofuran complexes 10 and 11 in which the chromium fragment is coordinated to the terminal unsubstituted benzoid ring. The molecular structures of both the kinetic annulation products and the thermodynamic rearrangement products were established by NMR spectroscopy and single crystal X-ray analysis.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.