1
|
Shin HS, Moon DY, An S, Park BS. Solvent assisted photochemical formation of a new keto[3,3]paracyclophane. Org Biomol Chem 2022; 20:4303-4308. [PMID: 35575223 DOI: 10.1039/d2ob00660j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photolysis of a phenacyl benzoate tethered with a phenol leads to a very efficient release of benzoic acid, which is suggested to occur by electron transfer and/or proton transfer from the remote phenol moiety to the triplet excited carbonyl. Photolysis of the compound in protic solvents forms a new keto[3,3]paracyclophane.
Collapse
Affiliation(s)
- Ho Suk Shin
- Department of Chemistry, Dongguk University, Seoul 04620, Korea.
| | - Da Yoon Moon
- Department of Chemistry, Dongguk University, Seoul 04620, Korea.
| | - Sejin An
- Department of Chemistry, Dongguk University, Seoul 04620, Korea.
| | - Bong Ser Park
- Department of Chemistry, Dongguk University, Seoul 04620, Korea.
| |
Collapse
|
2
|
Liu H, Gao H, Wang S, Yao S, Wu F, Zhao Y, Chan KS, Shen Z. Regulation of an Ambient-Light-Induced Photocyclization Pathway (Norrish-Yang Versus 6π) by Substituent Choice. Chemistry 2020; 26:12418-12430. [PMID: 32372418 DOI: 10.1002/chem.202000990] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 04/28/2020] [Indexed: 12/12/2022]
Abstract
Photocyclization, irrespective of whether multiple steps (e.g., Norrish-Yang cyclization) or a single concerted step (e.g., 6π photocyclization) are involved, is an intramolecular photochemical process resulting in the formation of one new single bond to afford a ring system. In particular, visible-light-induced photocyclization offers a green and sustainable route to organic cyclic compounds that are difficult to access by thermal reactions. Herein, we describe the ambient light-induced intramolecular photocyclization of a series of donor/acceptor chromophores 1 d-3 d containing two types of photoresponsive motifs, namely an electron-deficient BF2 -chelated ketone fused with an electron-rich thiophene, and probe the solution-phase and solid-state photochromic performance of these compounds. The results reveal that simple variation of R substituents on the diaryl moiety allows one to control the intramolecular photocyclization mechanism with high photochemical selectivity, e.g., under ambient light, methyl-substituted 1 d and 2 d undergo reversible 6π photocyclization, whereas ethyl-substituted 3 d exclusively undergoes irreversible Norrish-Yang photocyclization. Single-crystal X-ray analysis of Norrish-Yang cyclization products reveals the formation of four pairs of conformational enantiomers differing in the dihedral angle between benzothiophene and the BF2 core, namely (±)N-3 d@68°, (±)N-3 d@-77°, (±)N-3 d@-78°, and (±)N-3 d@-102°. The UV/Vis absorption spectra of 1 d-3 d cover a broad visible-light region (380-572 nm), while DFT and TD-DFT calculations reveal that absorption in this region is dominated by the charge-transfer (CT) transition from the thiophene-centered HOMO to the LUMO of the electron-deficient π-conjugated BF2 -chelated unit and the n→π* and π→π* transitions within the latter unit. The spatial separation of the HOMO and LUMO of these dyes promotes triplet-state generation and self-photosensitizes intramolecular photocyclization in the visible-light region. Three-dimensional time-resolved and steady-state emission spectra of 3 d show that the Norrish-Yang photocyclization takes place within milliseconds with excellent conversion efficiency (96 %).
Collapse
Affiliation(s)
- Hui Liu
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering Nanjing University, Nanjing, 210046, P. R. China
| | - Hu Gao
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering Nanjing University, Nanjing, 210046, P. R. China
| | - Sisi Wang
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering Nanjing University, Nanjing, 210046, P. R. China
| | - Shengxin Yao
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering Nanjing University, Nanjing, 210046, P. R. China
| | - Fan Wu
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering Nanjing University, Nanjing, 210046, P. R. China
| | - Yue Zhao
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering Nanjing University, Nanjing, 210046, P. R. China
| | - Kin Shing Chan
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering Nanjing University, Nanjing, 210046, P. R. China
| | - Zhen Shen
- State Key Laboratory of Coordination Chemistry, Collaborative Innovation Center of Advanced Microstructures, School of Chemistry and Chemical Engineering Nanjing University, Nanjing, 210046, P. R. China
| |
Collapse
|
3
|
Kim SH, Jang M, Moon DY, Park BS. Leaving group effect on photochemistry of ortho-alkylphenacyl carboxylate. Tetrahedron Lett 2018. [DOI: 10.1016/j.tetlet.2018.10.042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|