1
|
Zhao Z, Deng G, Li CC. Synthesis of the [6-6-7-5-5] Pentacyclic Core of Calyciphylline N. Org Lett 2024; 26:2238-2242. [PMID: 38442391 DOI: 10.1021/acs.orglett.4c00437] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2024]
Abstract
A new approach for the concise 11-step synthesis of the [6-6-7-5-5] BCDEF pentacyclic core of calyciphylline N is described. A type II [5 + 2] cycloaddition was employed to construct the strained BCD skeleton, which encompasses the challenging bicyclo[2.2.2] and bicyclo[4.3.1] ring systems. With a regio- and diastereoselective Lu's [3 + 2] cycloaddition, followed by intramolecular aldol cyclization and elimination, the desired [5-5]-fused EF ring system has been successfully installed, resulting in the complete carbocyclic skeleton of calyciphylline N.
Collapse
Affiliation(s)
- Zhiwen Zhao
- Shenzhen Grubbs Institute, Department of Chemistry, Guangming Advanced Research Institute, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Guowei Deng
- Shenzhen Grubbs Institute, Department of Chemistry, Guangming Advanced Research Institute, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
| | - Chuang-Chuang Li
- Shenzhen Grubbs Institute, Department of Chemistry, Guangming Advanced Research Institute, Southern University of Science and Technology, Shenzhen, Guangdong 518055, People's Republic of China
- Shenzhen Bay Laboratory, Shenzhen, Guangdong 518132, People's Republic of China
| |
Collapse
|
2
|
Yu X, Xiao L, Luo T. Enantioselective Total Synthesis of (-)-Vinigrol: The Evolution of a Transannular Diels-Alder Strategy. J Org Chem 2024; 89:1709-1718. [PMID: 38204139 DOI: 10.1021/acs.joc.3c02407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2024]
Abstract
Vinigrol is a structurally and stereochemically complex diterpenoid that displays various potent pharmacological activities. Two generations of synthetic routes were designed and pursued based on a transannular Diels-Alder (TADA) cycloaddition strategy. An intramolecular [2 + 2]photocycloaddition in the presence of the chelating Lewis acid (MgBr2·Et2O) was first discovered to enable the reaction of sterically challenging substrates, which was followed by [2 + 2]cycloreversion to provide α-pyrones fused with a 10-membered ring. Eventually, a new and scalable synthetic route toward (-)-vinigrol was developed and provided over 600 mg materials, manifesting the power of macrocyclic stereocontrol and TADA reaction.
Collapse
Affiliation(s)
- Xuerong Yu
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education and Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Lianghong Xiao
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education and Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Tuoping Luo
- Key Laboratory of Bioorganic Chemistry and Molecular Engineering, Ministry of Education and Beijing National Laboratory for Molecular Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
- Institute of Molecular Physiology, Shenzhen Bay Laboratory, Shenzhen, Guangdong 518055, China
| |
Collapse
|
3
|
Lin X, Min L, Li CC. Asymmetric Synthesis of the epi-Vinigrol Tricyclic Core Enabled by a Wolff Rearrangement Strategy and Formal Total Synthesis of (-)-Vinigrol. J Org Chem 2023; 88:14826-14830. [PMID: 37821441 DOI: 10.1021/acs.joc.3c01729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/13/2023]
Abstract
A new approach to construct the tricyclic framework of the diterpenoid vinigrol is described. The challenging 1,5-butanodecahydronaphthalene core was established efficiently and diastereoselectively through a combination of type II [5 + 2] cycloaddition and Wolff rearrangement. In addition, a formal total synthesis of (-)-vinigrol was achieved in 12 steps, in which Baran's intermediate was efficiently produced from a known compound by a two-step sequence involving a stereoselective α-hydroxylation and a diastereoselective α-ketol rearrangement.
Collapse
Affiliation(s)
- Xiaohong Lin
- Shenzhen Grubbs Institute, Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Long Min
- Shenzhen Grubbs Institute, Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Chuang-Chuang Li
- Shenzhen Grubbs Institute, Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
- Shenzhen Bay Laboratory, Shenzhen 518132, China
| |
Collapse
|
4
|
Arfan NHBZ, Hamid MHSA, Sheikh NS. A computational investigation towards substitution effects on 8π electrocyclisation of conjugated 1,3,5,7-octatetraenes. RSC Adv 2023; 13:30787-30797. [PMID: 37869396 PMCID: PMC10587816 DOI: 10.1039/d3ra05127g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 10/09/2023] [Indexed: 10/24/2023] Open
Abstract
A computational investigation using M06-2X/6-31+G(d) method is reported for the substitution effects on 8π electrocyclisation of conjugated octatetraene. This systematic study describes the mono- and di-substitution effect across the 1,3,5,7-octatetraene skeleton. A general preference of the outward substitution over the inward, at C1 position of the monosubstituted system is observed. However, mesomerically electron donating group (-NH2 and -OH) display an opposite effect with respect to secondary orbital interaction (SOI) between the lone pair on the substituent and the orbital. A comparative evaluation on the computed activation energies for the 1-, 2-, 3-, and 4-monosubstituted system showed an insignificant impact on the rate of the reaction, in contrast to the electrocyclic ring closure of the unsubstituted compound. Computations of disubstituted system are more pronounced, where a remarkable acceleration is observed for 2-NO2-7-NO2 substituted octatetraene at 4.9 kcal mol-1, and a noticeable deceleration for 4-CH3-5-CH3 substituted octatetraene at 25.4 kcal mol-1 from the parent molecule, 17.0 kcal mol-1. A visible accelerated effects are commonly exhibited by the substitution on the terminal double bonds (C1, C2, C7, and C8), that are 1,2-, 1,7-, 1,8-, and 2,7-patterns, in regard to the greater orbital interaction for the new σ-bond formation. Despite the unfavourable steric clashes of the substituents in the 1,8-system, an apparent reduction in the energy barrier up to 7.4 kcal mol-1 is computed for 1-NH2-8-NO2 system from 17.0 kcal mol-1. This is due to the synergistic effect of the electron donor and electron acceptor, enhancing the stability of the transition structure. The electrocyclic ring closure involving vicinal substitution patterns, such as 1,2-, 2,3-, 3,4-, and 4,5-systems are critically dominated by steric crowding between the adjacent functional groups. In certain cases of the 1,2-substituted system, a noticeable accelerated effects are found for 1-NH2-2-NH2-substituted compound (9.7 kcal mol-1) due to an increased in electronic density on the substituted terminal double bond (C1-C2), hence favouring the formation of the new σ-bond.
Collapse
Affiliation(s)
- Nur Hazimah B Z Arfan
- Chemical Sciences, Faculty of Science, Universiti Brunei Darussalam Jalan Tungku Link, Gadong BE1413 Brunei Darussalam
| | - Malai Haniti S A Hamid
- Chemical Sciences, Faculty of Science, Universiti Brunei Darussalam Jalan Tungku Link, Gadong BE1413 Brunei Darussalam
| | - Nadeem S Sheikh
- Chemical Sciences, Faculty of Science, Universiti Brunei Darussalam Jalan Tungku Link, Gadong BE1413 Brunei Darussalam
| |
Collapse
|
5
|
Zeng W, Zhang X, Zhang Y, Xiao S, Tang Y, Xie P, Loh TP. Organophotoredox-Catalyzed Intermolecular Formal Grob Fragmentation of Cyclic Alcohols with Activated Allylic Acetates. Org Lett 2023; 25:5869-5874. [PMID: 37515785 DOI: 10.1021/acs.orglett.3c02129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2023]
Abstract
We have developed an efficient method that employs organophotoredox-catalyzed relay Grob fragmentation to facilitate the smooth ring-opening allylation of cyclic alcohols in an environmentally friendly manner. This protocol directly incorporates a wide spectrum of cyclic alcohols and activated allylic acetates into the cross-coupling reaction, eliminating the need for metal catalysts. The process yields a variety of distally unsaturated ketones with good to excellent outcomes and stereoselectivity, while acetic acid is the sole byproduct.
Collapse
Affiliation(s)
- Wubing Zeng
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China
| | - Xiaoyu Zhang
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China
| | - Yinlei Zhang
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China
| | - Shiji Xiao
- Jiangsu BioGuide Laboratory Co., Ltd, Wujin Economic Development Zone, Changzhou 213000, Jiangsu, China
| | - Yongming Tang
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China
| | - Peizhong Xie
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China
| | - Teck-Peng Loh
- School of Chemistry and Molecular Engineering, Nanjing Tech University, Nanjing 211816, P. R. China
- College of Advanced Interdisciplinary Science and Technology, Henan University of Technology, Zhengzhou 450001, China
- Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371
| |
Collapse
|
6
|
Hui C, Craggs L, Antonchick AP. Ring contraction in synthesis of functionalized carbocycles. Chem Soc Rev 2022; 51:8652-8675. [PMID: 36172989 DOI: 10.1039/d1cs01080h] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Carbocycles are a key and widely present structural motif in organic compounds. The construction of structurally intriguing carbocycles, such as highly-strained fused rings, spirocycles or highly-functionalized carbocycles with congested stereocenters, remains challenging in organic chemistry. Cyclopropanes, cyclobutanes and cyclopentanes within such carbocycles can be synthesized through ring contraction. These ring contractions involve re-arrangement of and/or small molecule extrusion from a parental ring, which is either a carbocycle or a heterocycle of larger size. This review provides an overview of synthetic methods for ring contractions to form cyclopropanes, cyclobutanes and cyclopentanes en route to structurally intriguing carbocycles.
Collapse
Affiliation(s)
- Chunngai Hui
- Max Planck Institute of Molecular Physiology, Department of Chemical Biology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany. .,Technical University Dortmund, Faculty of Chemistry and Chemical Biology, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany
| | - Luke Craggs
- Nottingham Trent University, School of Science and Technology, Department of Chemistry and Forensics, Clifton Lane, NG11 8NS Nottingham, UK
| | - Andrey P Antonchick
- Max Planck Institute of Molecular Physiology, Department of Chemical Biology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany. .,Technical University Dortmund, Faculty of Chemistry and Chemical Biology, Otto-Hahn-Strasse 6, 44221 Dortmund, Germany.,Nottingham Trent University, School of Science and Technology, Department of Chemistry and Forensics, Clifton Lane, NG11 8NS Nottingham, UK
| |
Collapse
|
7
|
Witte JM, Service J, Addo MA, Semakieh B, Collins E, Sams C, Dorsey TR, Garrelts E, Blumenshine CA, Cooper T, Martinez M, Hamaker CG, Ferrence GM, Hitchcock SR. Diastereoselective and Enantioselective Synthesis of α- p-Methoxyphenoxy-β-Lactones: Dependence on the Stereoelectronic Properties of the β-Hydroxy-α- p-Methoxyphenoxycarboxylic Acid Precursors. J Org Chem 2022; 87:9619-9634. [PMID: 35862509 DOI: 10.1021/acs.joc.2c00608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Treatment of β-hydroxy-α-p-methoxyphenoxy carboxylic acids derived from the asymmetric glycolate aldol addition reaction with p-nitrobenzenesulfonyl chloride yielded divergent results depending on the nature of the β-substituent of the carboxylic acid. Substrates bearing either alkyl substituents (R = -n-butyl, -n-octyl, -benzyl, isopropyl, -tert-butyl) or aryl systems bearing electron-withdrawing substituents (R = -p-C6H4Cl, -p-C6H4Br, -p-C6H4NO2) yielded β-lactones. In contrast, α-p-methoxyphenoxy-β-hydroxycarboxylic acids bearing electron-donating aryl groups or the sterically demanding 2-naphthyl group formed (Z)-alkenes.
Collapse
Affiliation(s)
- Jordan M Witte
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Jasmine Service
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Marian Aba Addo
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Bader Semakieh
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Erin Collins
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Christopher Sams
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Timothy R Dorsey
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Elizabeth Garrelts
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Cassidy A Blumenshine
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Trace Cooper
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Moses Martinez
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Christopher G Hamaker
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Gregory M Ferrence
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| | - Shawn R Hitchcock
- Department of Chemistry, Illinois State University, Normal, Illinois 61790-4160, United States
| |
Collapse
|
8
|
Wei W, Li Y, Wang C, Gao S, Zhao Y, Yang Z, Wang H, Gao Z, Jiang Y, He Y, Zhao L, Gao H, Yao X, Hu Y. Diterpenoid Vinigrol specifically activates ATF4/DDIT3-mediated PERK arm of unfolded protein response to drive non-apoptotic death of breast cancer cells. Pharmacol Res 2022; 182:106285. [PMID: 35662627 DOI: 10.1016/j.phrs.2022.106285] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Revised: 05/23/2022] [Accepted: 05/29/2022] [Indexed: 11/26/2022]
Abstract
Vinigrol is a natural diterpenoid with unprecedented chemical structure, driving great efforts into its total synthesis in the past decades. Despite anti-hypertension and anti-clot ever reported, comprehensive investigations on bioactions and molecular mechanisms of Vinigrol are entirely missing. Here we firstly carried out a complete functional prediction of Vinigrol using a transcriptome-based strategy coupled with multiple bioinformatic analyses and identified "anti-cancer" as the most prominent biofunction ahead of anti-hypertension and anti-depression/psychosis. Broad cytotoxicity was subsequently confirmed on multiple cancer types. Further mechanistic investigation on several breast cancer cells revealed that its anti-cancer effect was mainly through activating PERK/eIF2α arm of unfolded protein response (UPR) and subsequent non-apoptotic cell death independent of caspase activities. The other two branches of UPR, IRE1α and ATF6, were functionally irrelevant to Vinigrol-induced cell death. Using CRISPR/Cas9-based gene activation, repression, and knockout systems, we identified the essential contribution of ATF4 and DDIT3, not ATF6, to the death process. This study unraveled a broad anti-cancer function of Vinigrol and its underlying targets and regulatory mechanisms. It paved the way for further inspection on the structure-efficacy relationship of the whole compound family, making them a novel cluster of PERK-specific stress activators for experimental and clinical uses.
Collapse
Affiliation(s)
- Wencheng Wei
- Harbin Institute of Technology, Harbin 150000, China; Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China
| | - Yunfei Li
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China
| | - Chuanxi Wang
- Institute of Traditional Chinese Medicine & Natural Products, College of Pharmacy, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, Jinan University, Guangzhou 510632, China
| | - Sanxing Gao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China
| | - Yan Zhao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China
| | - Zhenyu Yang
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China
| | - Hao Wang
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China
| | - Ziying Gao
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China
| | - Yanxiang Jiang
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China
| | - Yuan He
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China
| | - Li Zhao
- Department of Head and Neck Surgical Oncology, National Clinical Research Center for Cancer, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100000, China
| | - Hao Gao
- Institute of Traditional Chinese Medicine & Natural Products, College of Pharmacy, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, Jinan University, Guangzhou 510632, China.
| | - Xinsheng Yao
- Institute of Traditional Chinese Medicine & Natural Products, College of Pharmacy, Guangdong Province Key Laboratory of Pharmacodynamic Constituents of TCM and New Drugs Research, Jinan University, Guangzhou 510632, China
| | - Yuhui Hu
- Shenzhen Key Laboratory of Gene Regulation and Systems Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China; Department of pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen 518005, China; Department of Biology, School of Life Sciences, Southern University of Science and Technology, Shenzhen 518005, China.
| |
Collapse
|
9
|
Harry NA, Ujwaldev SM. Recent advances in [5+2] cycloadditions. CURR ORG CHEM 2022. [DOI: 10.2174/1385272826666220510152025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abstract:
The existence of a seven-membered cyclic core in several natural products and biomolecules vitalized the research on its synthesis. [5+2] cycloaddition has become a promising strategy for the construction of seven-membered ring systems by the formation of carbon-carbon bonds in a single step, with strong regioselectivity and stereoselectivity. This review mainly focuses on recent developments in the area of [5+2] cycloaddition since 2019. Total synthesis of natural products involving [5+2] cycloaddition as key step leading to heptacyclic core is also discussed. Synthesis of fused and bridged ring systems via the reactions involving inter and intramolecular [5+2] cycloadditions like oxidopyrylium-mediated [5+2] cycloadditions, [5+2] cycloadditions of vinyl cyclopropanes (VCPs), vinyl phenols, etc is explained in the review with the latest examples. This review provides a useful guide for researchers exploring this powerful strategy to create more elegant heptacycles in their future research.
Collapse
|
10
|
Abstract
Terpenoids constitute a broad class of natural compounds with tremendous variability in structure and bioactivity, which resulted in a strong interest of the chemical community to this class of natural products over the last 150 years. The presence of strained small rings renders the terpenoid targets interesting for chemical synthesis, due to limited number of available methods and stability issues. In this feature article, a number of recent examples of total syntheses of terpenoids with complex carbon frameworks featuring small rings are discussed. Specific emphasis is given to the new developments in strategical and tactical approaches to construction of such systems.
Collapse
Affiliation(s)
- Gleb A Chesnokov
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
| | - Karl Gademann
- Department of Chemistry, University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
| |
Collapse
|
11
|
Khatri HR, Han C, Alkhodier RA, Adam AT, Islam B, Colby DA. Generation of formaldehyde and formaldehyde-d 2 for hydroxymethylations and hydroxydeuteromethylations of difluoroenolates and difluorobenzyl carbanions. Chem Commun (Camb) 2022; 58:5490-5493. [PMID: 35416212 PMCID: PMC9205602 DOI: 10.1039/d2cc01518h] [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
A method for the in situ production of formaldehyde from dimethylsulfoxide, bromine, and cesium carbonate is reported for reactions with difluoroenolates and difluorobenzyl carbanions. This process also generates formaldehyde-d2 for the production of 2,2-difluoro-1,1-deuteroethanols. Mechanistic and computational studies further characterize the production of hydroxymethylated and hydroxydeuteromethylated difluorinated organic molecules.
Collapse
Affiliation(s)
- Hari R Khatri
- Department of BioMolecular Sciences, University of Mississippi, University Mississippi, USA.
| | - Changho Han
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, Indiana, USA
| | - Reem A Alkhodier
- Department of BioMolecular Sciences, University of Mississippi, University Mississippi, USA.
| | - Amna T Adam
- Department of BioMolecular Sciences, University of Mississippi, University Mississippi, USA.
| | - Baharul Islam
- Department of BioMolecular Sciences, University of Mississippi, University Mississippi, USA.
| | - David A Colby
- Department of BioMolecular Sciences, University of Mississippi, University Mississippi, USA.
| |
Collapse
|
12
|
Abstract
Taxol is one of the most famous natural diterpenoids and an important anticancer medicine. Taxol represents a formidable synthetic challenge and has prompted significant interest from the synthetic community. However, in all the previous syntheses of Taxol, there have been no reports of closing the desired eight-membered ring through C1-C2 bond formation. Furthermore, the existence of Taxol-resistant tumors and side effects of Taxol make the development of new approaches to synthesize Taxol and its derivatives highly desirable. Here, we report the asymmetric total synthesis of Taxol using a concise approach through 19 isolated intermediates. The synthetically challenging eight-membered ring was constructed efficiently by a diastereoselective intramolecular SmI2-mediated pinacol coupling reaction to form the C1-C2 bond. The unique biomimetic oxygen ene reaction and the newly developed facile tandem C2-benzoate formation and C13 side chain installation improved the efficiency of the synthesis. The mild oxygen ene reaction under light conditions would be an alternative reaction involved in Taxol biosynthesis. This new convergent approach will allow the diverse creation of Taxol derivatives to enable further biological research.
Collapse
Affiliation(s)
- Ya-Jian Hu
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Chen-Chen Gu
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Xin-Feng Wang
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Long Min
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Chuang-Chuang Li
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| |
Collapse
|
13
|
Wu J, Liu J, Fan J, Xie Z, Qin H, Li C. Evolution of Routes for Asymmetric Total Synthesis of Cyclocitrinol Enabled by Type
II
[5+2] Cycloaddition
†. CHINESE J CHEM 2021. [DOI: 10.1002/cjoc.202000698] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Jianlei Wu
- Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen Guangdong 518055 China
| | - Junyang Liu
- Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen Guangdong 518055 China
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology Shenzhen Guangdong 518055 China
| | - Jian‐Hong Fan
- Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen Guangdong 518055 China
| | - Zhi‐Dong Xie
- Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen Guangdong 518055 China
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology Shenzhen Guangdong 518055 China
| | - Hukun Qin
- Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen Guangdong 518055 China
| | - Chuang‐Chuang Li
- Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Department of Chemistry, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen Guangdong 518055 China
| |
Collapse
|
14
|
Affiliation(s)
- Guodong Zhao
- School of Chinese Pharmacy, Beijing University of Chinese Medicine, Beijing 102488, China
| | | | | | - Rongbiao Tong
- HKUST Shenzhen Research Institute, Shenzhen 518057, China
| |
Collapse
|
15
|
Brandau NM, Wiget PA. Bicyclic cycloadduct fragmentations as a means of stereocontrol. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2020.152795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
16
|
Abstract
The synthetically challenging and highly functionalized azabicyclo[6.4.1] ring system, which is found in lycopodium alkaloid lycoclavatumide and some natural molecules, was synthesized for the first time. The key reaction was a diastereoselective type II [5+2] cycloaddition with excellent functional group compatibility. We tried to install the desired eight-membered ring in the final product by RCM reaction.
Collapse
Affiliation(s)
- Xin-Feng Wang
- Shenzhen Grubbs Institute, Department of Chemistry, Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Bin Wang
- Shenzhen Grubbs Institute, Department of Chemistry, Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| | - Chuang-Chuang Li
- Shenzhen Grubbs Institute, Department of Chemistry, Guangdong Provincial Key Laboratory of Catalytic Chemistry, Southern University of Science and Technology, Shenzhen 518055, China
| |
Collapse
|
17
|
Fernandes RA, Kumar P, Choudhary P. Evolution of Strategies in Protecting‐Group‐Free Synthesis of Natural Products: A Recent Update. European J Org Chem 2020. [DOI: 10.1002/ejoc.202001246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Rodney A. Fernandes
- Department of Chemistry Indian Institute of Technology Bombay 400076 Mumbai, Powai Maharashtra India
| | - Praveen Kumar
- Department of Chemistry Indian Institute of Technology Bombay 400076 Mumbai, Powai Maharashtra India
| | - Priyanka Choudhary
- Department of Chemistry Indian Institute of Technology Bombay 400076 Mumbai, Powai Maharashtra India
| |
Collapse
|
18
|
Huang H, Mi F, Li C, He H, Wang F, Liu X, Qin Y. Total Synthesis of Liangshanone. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202011923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Hong‐Xiu Huang
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Fen Mi
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Chunxin Li
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Huan He
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Feng‐Peng Wang
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Xiao‐Yu Liu
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Yong Qin
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| |
Collapse
|
19
|
Huang H, Mi F, Li C, He H, Wang F, Liu X, Qin Y. Total Synthesis of Liangshanone. Angew Chem Int Ed Engl 2020; 59:23609-23614. [PMID: 32902096 DOI: 10.1002/anie.202011923] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Indexed: 12/18/2022]
Affiliation(s)
- Hong‐Xiu Huang
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Fen Mi
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Chunxin Li
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Huan He
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Feng‐Peng Wang
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Xiao‐Yu Liu
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| | - Yong Qin
- Key Laboratory of Drug Targeting and Drug Delivery Systems of the Education Ministry and Sichuan Province Sichuan Engineering Laboratory for Plant-Sourced Drugs and Sichuan Research Center for Drug Precision Industrial Technology West China School of Pharmacy Sichuan University Chengdu 610041 China
| |
Collapse
|
20
|
Min L, Hu YJ, Fan JH, Zhang W, Li CC. Synthetic applications of type II intramolecular cycloadditions. Chem Soc Rev 2020; 49:7015-7043. [PMID: 32869796 DOI: 10.1039/d0cs00365d] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Type II intramolecular cycloadditions ([4+2], [4+3], [4+4] and [5+2]) have emerged recently as an efficient and powerful strategy for the construction of bridged ring systems. In general, type II cycloadditions provide access to a wide range of bridged bicyclo[m.n.1] ring systems with high regio- and diastereoselectivity in an easy and straightforward manner. In each section of this review, an overview of the corresponding type II cycloadditions is presented, which is followed by highlights of method development and synthetic applications in natural product synthesis. The goal of this review is to provide a survey of recent advances in the field covering literature up to 2020. The review will serve as a useful reference for organic chemists engaged in the total synthesis of natural products containing bridged bicyclo[m.n.1] ring systems and provide strong stimulus for invention and further advances in this exciting research field.
Collapse
Affiliation(s)
- Long Min
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China.
| | | | | | | | | |
Collapse
|
21
|
Photo-physical properties of vinigrol revealed by two-photon absorption, electronic circular dichroism, Raman spectroscopy and Raman optical activity. Chem Phys Lett 2020. [DOI: 10.1016/j.cplett.2020.137798] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
22
|
Hu YJ, Li LX, Han JC, Min L, Li CC. Recent Advances in the Total Synthesis of Natural Products Containing Eight-Membered Carbocycles (2009-2019). Chem Rev 2020; 120:5910-5953. [PMID: 32343125 DOI: 10.1021/acs.chemrev.0c00045] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Natural products containing eight-membered carbocycles constitute a class of structurally intriguing and biologically important molecules such as the famous diterpenes taxol and vinigrol. Such natural products are being increasingly investigated because of their fascinating architectural features and potent medicinal properties. However, synthesis of natural products with cyclooctane moieties has proved to be highly challenging. This review highlights the recently completed total syntheses of natural products with eight-membered carbocycles with a focus on strategic considerations. A collection of 27 representative studies from the literature covering the decade from 2009 to 2019 is described in chronological order with relevant studies grouped together, including syntheses of the same natural product by different research groups using different strategies. Finally, a summary and outlook including a discussion of the major features of each strategy used in the syntheses are presented. This review illustrates the diversity and creativity in the elegant synthetic designs of eight-membered carbocycles. We hope this review will provide timely illumination and beneficial guidance for future synthetic efforts for organic chemists who are interested in this area.
Collapse
Affiliation(s)
- Ya-Jian Hu
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Li-Xuan Li
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Jing-Chun Han
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Long Min
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Chuang-Chuang Li
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| |
Collapse
|
23
|
Min L, Liu X, Li CC. Total Synthesis of Natural Products with Bridged Bicyclo[m.n.1] Ring Systems via Type II [5 + 2] Cycloaddition. Acc Chem Res 2020; 53:703-718. [PMID: 32069021 DOI: 10.1021/acs.accounts.9b00640] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Natural products containing bridged ring systems are widely identified and show significant biological activity. The development of efficient synthesis reactions and strategies to construct bridged ring systems is a long-standing but very significant challenge in organic chemistry. In 2014, our group developed a unique type II [5 + 2] cycloaddition reaction that provides a facile and direct methodology for constructing highly functionalized bridged bicyclo[4.3.1], bicyclo[4.4.1], bicyclo[5.4.1], bicyclo[6.4.1], and other bicyclo[m.n.1] systems containing a strained bridgehead double bond. In this Account, we summarize the methodology development and report the results of application of our unique strategy for the total synthesis of several natural products with bridged ring systems (i.e., cyclocitrinol, cerorubenic acid-III, and vinigrol) during the past 5 years in our laboratory. In the first part, we introduce the logic behind the design and discovery of type II [5 + 2] cycloadditions. The substrates can be easily synthesized by a modular approach, followed by base-promoted group elimination under heat to form an oxidopyrylium ylide, which can undergo cycloaddition under relatively mild conditions with a variety of double bonds to generate bridged bicyclo[m.n.1] frameworks in high yield. The diastereocontrol and unique endo selectivity of this methodology are favorable for further application to the synthesis of complex natural products. In the second part, we highlight our endeavors in the total synthesis of several different types of molecules bearing bridged ring systems using our methodology. The bridged bicyclo[4.4.1] system is the core structure of two different types of natural products, cyclocitrinol and cerorubenic acid-III, that can be efficiently constructed by type II [5 + 2] cycloadditions. The development of suitable strategies and methods for site-selective cleavage of the C-O bond of the oxa-[3.2.1] ring system in the products of type II [5 + 2] cycloadditions is also discussed and highlighted during the syntheses. Moreover, the bridged bicyclo[5.3.1] system is the core structure of vinigrol, which can be constructed through a novel ring contraction sequence of the bicyclo[5.4.1] system formed by a type II [5 + 2] cycloaddition. By combining with a ring contraction cascade, we believe that type II [5 + 2] cycloadditions have the potential to be used as a unified approach to constructing natural products containing bridged bicyclo[m.n.1] frameworks.
Collapse
Affiliation(s)
- Long Min
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Xin Liu
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| | - Chuang-Chuang Li
- Shenzhen Grubbs Institute and Department of Chemistry, Southern University of Science and Technology (SUSTech), Shenzhen 518055, China
| |
Collapse
|
24
|
Bejcek LP, Murelli RP. Synthesis of aryl-substituted 2-methoxyphenol derivatives from maltol-derived oxidopyrylium cycloadducts through an acid-mediated ring contraction cascade. Chem Commun (Camb) 2020; 56:3203-3205. [PMID: 32068199 PMCID: PMC7560963 DOI: 10.1039/c9cc09213g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oxidopyrylium cycloadducts derived from maltol and aryl acetylenes undergo acid-mediated rearrangements to generate aryl-substituted 2-methoxyphenol (guaiacol) derivatives. Specifically, the cycloadducts react with boron trichloride to form 2-methoxy-5-arylphenol molecules, and with methane sulfonate to form 2-methoxy-4-aryl-6-methylphenol molecules.
Collapse
Affiliation(s)
- Lauren P Bejcek
- Department of Chemistry, Brooklyn College, The City University of New York, Brooklyn, NY, USA.
| | | |
Collapse
|
25
|
|
26
|
Zhang L, Shi Q, Cao T, Zhu S. Catalytic regio- and stereoselective intermolecular [5+2] cycloaddition via conjugative activation of oxidopyrylium. Chem Commun (Camb) 2020; 56:9533-9536. [PMID: 32691033 DOI: 10.1039/d0cc04309e] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A catalytic stereodivergent intermolecular [5+2] cycloaddition of maltol-type oxidopyrylium through conjugative activation was reported.
Collapse
Affiliation(s)
- Ling Zhang
- Key Lab of Functional Molecular Engineering of Guangdong Province
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou 510640
- P. R. China
| | - Qiu Shi
- Key Lab of Functional Molecular Engineering of Guangdong Province
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou 510640
- P. R. China
| | - Tongxiang Cao
- Key Lab of Functional Molecular Engineering of Guangdong Province
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou 510640
- P. R. China
| | - Shifa Zhu
- Key Lab of Functional Molecular Engineering of Guangdong Province
- School of Chemistry and Chemical Engineering
- South China University of Technology
- Guangzhou 510640
- P. R. China
| |
Collapse
|