Abstract
AbstractDeprotonation reactions of N‐benzyl‐ and N‐allylimines 1 and 4 led to benzo‐annulated 2‐azaheptatrienyl‐ and 4‐azanonatetraenyllithium compounds, which underwent 1,7‐electrocyclization reactions to yield the novel 2,3‐dihydro‐1H‐benzo[c]azepines 3, 5, 11 and 13 or the (5,6‐dihydrobenzocycloocten‐5‐yl)amines 6 after subsequent addition of acyl chlorides, carbamoyl chlorides, imidoyl chlorides or pivaldehyde, respectively. Acyl and carbamoyl chlorides reacted as electrophiles at the nitrogen atom, whereas imidoyl halides and pivaldehyde attacked position C‐5 in the seven‐membered ring. In the case of pivaldehyde, the final tricyclic product 13 is the result of a subsequent nucleophilic attack at the imine moiety after a proton shift. The temperature dependence of the reaction cascades was studied, allowing preferred formation either of the seven‐membered heterocyclic systems 3 and 5 or of the eight‐membered carbocycles 6. All compounds were fully characterized, including by X‐ray diffraction studies of 6c, 6f, 11a and 13a. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
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.