1
|
Pu Y, Shi J, Shi B, Li G, Du Y. Quaternized chitin used as chiral stationary phase for HPLC and the high enantioseparation of 1,2,3,4-tetrahydro-1-naphthalenamine racemates. Int J Biol Macromol 2021; 193:809-813. [PMID: 34728299 DOI: 10.1016/j.ijbiomac.2021.10.202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/19/2021] [Accepted: 10/26/2021] [Indexed: 11/30/2022]
Abstract
Quaternized chitin (QC) with different degrees of substitution (DSs) and molecular weight (Mw) were homogeneously synthesized. Eight novel chiral stationary phases (CSPs) for HPLC were prepared by coating the QC on 3-aminopropyl silica gel, which were firstly used to separate 1,2,3,4-tetrahydro-1-naphthalenamine (THNA) racemates. Enantioseparation capability of the CSPs was evaluated and the influence factors including DS and Mw of QCs were explored respectively. The results demonstrated that the successful separation of THNA enantiomers was obtained by all the new CSPs of the chitin derivatives. Resolution (Rs) increased from 1.12 to 1.58 with the increase of DS of QC from 0.40 to 0.62, while the Rs decreased with the reduction of Mw of the products from 2.8 × 105 to 9.7 × 104. The maximum Rs is 2.29. A simple pathway for the fabrication of novel CSPs of cationic chitin derivatives is developed, which has potential application for the separation of THAN racemates.
Collapse
Affiliation(s)
- Yuanlin Pu
- Pediatric Intensive Care Unit, The Central Hospital of Enshi Tujia and Miao Autonomous Prefecture, Enshi 445000, China
| | - Jie Shi
- School of Chemical and Environmental Engineering, Key Laboratory of Biological Resources Protection and Utilization of Hubei Province, Hubei Minzu University, Enshi 445000, China
| | - Boan Shi
- School of Chemical and Environmental Engineering, Key Laboratory of Biological Resources Protection and Utilization of Hubei Province, Hubei Minzu University, Enshi 445000, China
| | - Guoxiang Li
- School of Chemical and Environmental Engineering, Key Laboratory of Biological Resources Protection and Utilization of Hubei Province, Hubei Minzu University, Enshi 445000, China.
| | - Yumin Du
- School of Resource and Environmental Science, Wuhan University, Wuhan 430079, China
| |
Collapse
|
2
|
Jones L, Whitaker BJ. Modeling a halogen dance reaction mechanism: A density functional theory study. J Comput Chem 2016; 37:1697-703. [PMID: 27075112 DOI: 10.1002/jcc.24385] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Revised: 03/18/2016] [Accepted: 03/21/2016] [Indexed: 11/10/2022]
Abstract
Since the discovery of the halogen dance (HD) reaction more than 60 years ago, numerous insights into the mechanism have been unveiled. To date however, the reaction has not been investigated from a theoretical perspective. Density functional theory (DFT) was used to model the potential energy surface linking the starting reagents to the lithiated products for each step in the mechanism using a thiophene substrate. It was found that the lithium-halogen exchange mechanism is critical to understand the HD mechanism in detail and yielded the knowledge that SN 2 transition states (TS) are favored over the four-center type for the lithium-bromine exchange steps. The overall driving force for the HD is thermodynamics, while the kinetic factors tightly control the reaction path through temperature. The SN 2 lithium-bromide TS are barrierless, except the second, which is the limiting step. Finally, the model for the HD is discovered to be a pseudo-clock type, due to a highly favorable bromide catalysis step and the reformation of 2-bromothiophene. © 2016 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Leighton Jones
- School of Chemistry, University of Leeds, LS2 9JT, United Kingdom
| | | |
Collapse
|
3
|
Pretali L, Dondi D, D’Angelantonio M, Manet I, Fasani E, Monti S, Bovio B, Albini A. A Fluorine 1,2-Migration via Aryl Cation/Radical/Radical Anion/Radical Sequence. Org Lett 2013; 15:3926-9. [DOI: 10.1021/ol401670p] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Luca Pretali
- Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy, and Institute for Organic Synthesis and Photoreactivity, CNR, via P. Gobetti 101, 40129 Bologna, Italy
| | - Daniele Dondi
- Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy, and Institute for Organic Synthesis and Photoreactivity, CNR, via P. Gobetti 101, 40129 Bologna, Italy
| | - Mila D’Angelantonio
- Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy, and Institute for Organic Synthesis and Photoreactivity, CNR, via P. Gobetti 101, 40129 Bologna, Italy
| | - Ilse Manet
- Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy, and Institute for Organic Synthesis and Photoreactivity, CNR, via P. Gobetti 101, 40129 Bologna, Italy
| | - Elisa Fasani
- Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy, and Institute for Organic Synthesis and Photoreactivity, CNR, via P. Gobetti 101, 40129 Bologna, Italy
| | - Sandra Monti
- Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy, and Institute for Organic Synthesis and Photoreactivity, CNR, via P. Gobetti 101, 40129 Bologna, Italy
| | - Bruna Bovio
- Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy, and Institute for Organic Synthesis and Photoreactivity, CNR, via P. Gobetti 101, 40129 Bologna, Italy
| | - Angelo Albini
- Department of Chemistry, University of Pavia, via Taramelli 12, 27100 Pavia, Italy, and Institute for Organic Synthesis and Photoreactivity, CNR, via P. Gobetti 101, 40129 Bologna, Italy
| |
Collapse
|