open access

https://hdl.handle.net/2115/91392

Chiral Calix[3]pyrrole Derivatives: Synthesis, Racemization Kinetics, and Ring Expansion to Calix[9]- and Calix[12]pyrrole Analogues

英語

Ring Expansion

2023-04-03

Wiley-Blackwell

Angewandte chemie - international edition

62(15)

e202301460

Chiral pyrrolic macrocycles continue to attract interest. However, their molecular design remains challenging. Here, we report a calixpyrrole-based chiral macrocyclic system, calix[1]furan[1]pyrrole[1]thiophene (1), synthesized from an oligoketone. Macrocycle 1 adopts a partial cone conformation in the solid state, and undergoes racemization via ring inversion. Molecular dynamics simulations revealed that inversion of the thiophene is the rate determining step. Pyrrole N-methylation suppressed racemization and permitted chiral resolution. Enantioselective N-methylation also occurred in the presence of a chiral ammonium salt, although the stereoselectivity is modest. A unique feature of 1 is that it acts as a useful synthetic precursor to yield several calix[n]furan[n]pyrrole[n]thiophene products (n=2-4), including a calix[12]pyrrole analogue that to our knowledge constitutes the largest calix[n]pyrrole-like species to be structurally characterized.

学術雑誌論文

Accepted Manuscript

This is the peer reviewed version of the following article: Inaba, Y., Yang, J., Kakibayashi, Y., Yoneda, T., Ide, Y., Hijikata, Y., Pirillo, J., Saha, R., Sessler, J. L., Inokuma, Y., /Angew. Chem. Int. Ed./ 2023, 62, e202301460, which has been published in final form at https://doi.org/10.1002/anie.202301460. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.

1433-7851

1521-3773

AA0052535X