Intramolecular nucleophilic aromatic substitution (Truce-Smiles rearrangement) of the anions of 2-benzyl benzanilides leads to triarylmethanes in an operationally simple manner. The reaction succeeds even without electronic activation of the ring that plays the role of electrophile in the SNAr reaction, being accelerated instead by the preferred conformation imposed by the tertiary amide tether. The amide substituent of the product may be removed or transformed into alternative functional groups. A ring-expanding variant (n to n + 4) of the reaction provided a route to doubly benzo-fused medium ring lactams of 10 or 11 members. Hammett analysis returned a r value consistent with the operation of a partially concerted reaction mechanism.
Bibliographical noteFunding Information:
The work was supported by the EPSRC Centre for Doctoral Training in Catalysis and the EPSRC Centre for Doctoral Training in Technology Enhanced Chemical Synthesis.
© 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH
- BCS and TECS CDTs
- Hammett plot
- medium ring
- Truce–Smiles rearrangement