1
|
Sirianni D, Song X, Wairegi S, Wang EB, Mendoza-Gomez SA, Luxon A, Zimmerley M, Nussdorf A, Filatov M, Hoffmann R, Parish CA. Variations on the Bergman Cyclization Theme: Electrocyclizations of Ionic Penta-, Hepta-, and Octadiynes. J Am Chem Soc 2023; 145:21408-21418. [PMID: 37747784 PMCID: PMC10557144 DOI: 10.1021/jacs.3c06691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Indexed: 09/26/2023]
Abstract
The Bergman cyclization of (Z)-hexa-3-ene-1,5-diyne to form the aromatic diradical p-benzyne has garnered attention as a potential antitumor agent due to its relatively low cyclization barrier and the stability of the resulting diradical. Here, we present a theoretical investigation of several ionic extensions of the fundamental Bergman cyclization: electrocyclizations of the penta-1,4-diyne anion, hepta-1,6-diyne cation, and octa-1,7-diyne dication, leveraging the spin-flip formulation of the equation-of-motion coupled cluster theory with single and double substitutions (EOM-SF-CCSD). Though the penta-1,4-diyne anion exhibits a large cyclization barrier of +66 kcal mol-1, cyclization of both the hepta-1,6-diyne cation and octa-1,7-diyne dication along a previously unreported triplet pathway requires relatively low energy. We also identified the presence of significant aromaticity in the triplet diradical products of these two cationic cyclizations.
Collapse
Affiliation(s)
- Dominic
A. Sirianni
- Department
of Natural Sciences, Daemen University, Amherst, New York 14226, United States
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Xinli Song
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Salmika Wairegi
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Evan B. Wang
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | | | - Adam Luxon
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Maxwell Zimmerley
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Ariana Nussdorf
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| | - Michael Filatov
- Department
of Chemistry, Southern Methodist University, Dallas, Texas 75275, United States
| | - Roald Hoffmann
- Department
of Chemistry, Cornell University, Ithaca, New York 14853, United States
| | - Carol A. Parish
- Department
of Chemistry, University of Richmond, Richmond, Virginia 23173, United States
| |
Collapse
|