Author Archive

Hole-mediated PhotoRedox Catalysis: Tris(p-substituted)biarylaminium Radical Cations as Tunable, Precomplexing and Potent Photooxidants

Hole-mediated PhotoRedox Catalysis: Tris(p-substituted)biarylaminium Radical Cations as Tunable, Precomplexing and Potent Photooxidants.

Processes involving visible light photoinduced electron transfer (PET) are at the forefront of contemporary organic synthesis and allow access to reactive intermediates unavailable from conventional chemical reactivity. The selective delivery of photon energy to visible light-active photocatalysts which engage visible light-inactive molecules in PET is now an established synthetic technology known as PhotoRedox Catalysis (PRC). PRC is broadly-applicable, selective, proceeds under exceedingly mild conditions and is changing the way we do organic synthesis. However, PRC suffers some key limitations. Firstly, excess sacrificial chemical oxidants (O2) or reductants (trialkylamines) are needed to turn over the ‘spent’ photocatalyst which can (or whose by-products, such as peroxides, can) interfere with subsequent chemical processes and need separation from desired products. Secondly, the scope of redox processes is fundamentally restricted by the energy of visible light photons (400-700 nm; 1.8-3.1 eV) and not all of this photon energy provided to the photocatalyst can be harnessed synthetically. Although high energy visible photons (400-450 nm) can temporarily populate excited states higher than the first excited state, Kasha’s rule dictates that relaxation to the first excited state is faster than typical diffusion-controlled photochemistry. This limits the applications of PRC in challenging redox processes.

Nature overcomes photon energy limitations by accumulating multiple photons for challenging chemical processes; several red photons are required for transfer of electrons to CO2 in biological photosynthesis. With some exceptions, harnessing of multiple photon energies in PRC to access super-oxidizing or super-reducing excited states has largely eluded researchers. The fusion of photochemistry and electrochemistry provides an innovative solution to all issues above. Electroactivation of a catalyst to a colored radical ion, followed by its photoexcitation, exceeds the accessible excited state redox potentials of PRC alone (>3.0 eV). Some examples of this concept, coined ‘electrochemically-mediated PhotoRedox Catalysis’ (e-PRC), have emerged in the literature. A question that has eluded researchers is how excited radical ions (typically doublet states) could ever engage in photochemistry, given their typical picosecond lifetimes forbid diffusion. Moreover, while catalyst ‘tunability’ is well established in PRC, it is yet to be established in synthetic photoelectrochemistry.

 

Figure 1. Triarylamines (TAAs) as tunable e-PRCats developed by the Barham grou.; A. SET activation of challenging arenes and C-N bond formation with N-heterocycles. B. Experimental setup showing electroactivation of TAAs and photoexcitation of TAA.+s in a divided cell.

Recently, the group of Joshua Philip Barham and collaborators at Universität Regensburg, Technische Universität München and the Central European Institute of Technology introduced triarylamines (TAA) as a new family of tunable electroactivated photoredox catalyst (e-PRCat). The group demonstrated that facile tuning of the e-PRCat accessed record-breaking excited state potentials of Epox = +4.4 V vs SCE. This allowed PET super-oxidations of very challenging arenes, like polychloroarenes, polyfluoroarenes and trifluorotoluene, resulting overall in C-N bond formation with pyrazole partners. Catalyst power could be tuned down to access moderately challenging arenes (alkylbenzenes, benzene) with higher selectivity. Of key importance is the discovery of p-stacking dispersion precomplexation between the radical ion e-PRCat (TAA.+) and substrate to rationalize, for the first time, the photochemistry of excited state radical ions. The study sets the scene for dispersive precomplexation as a novel control element in photochemistry, which allowed the group to:

1) circumvent of ultrashort lifetimes of radical ion excited states (*TAA.+, t < 10 ps) for use in PET,

2) override Kasha’s rule and access to higher order excited states, to harness the full power of the visible photon’s energy (Epox *TAA.+ > 4.0 V vs. SCE),

3) overturn conventional thermodynamic redox selectivity (1,4- > 1,2-disubstituted arenes) by steric/electronic factors involved in precomplexation (1,2- > 1,4-disubstituted arenes).

Figure 2. Proposed mechanism of hole-mediated photoredox catalytic super-oxidation of arenes, involving dispersive precomplexation via a T-p interaction, supported by DFT calculations and changes in EPR spectroscopy of the TAA.+ in the presence of arene substrates following a shift in spin density (increasing triplet representation of the signal).

 

Joshua Philip Barham

Universität Regensburg

Joshua Philip Barham is a Sofja Kovalevskaja Group Leader in the Faculty of Chemistry and Pharmacy at the University of Regensburg (Germany), where he investigates photo-, electro-, photoelectro- and flow chemistry as enabling technologies in organic synthesis. He received his industry-based Ph.D in Chemistry in 2017 under the supervision of Prof. John Murphy at the University of Strathclyde (U.K.) and Dr. Matthew John at GlaxoSmithKline (U.K.). His postdoctoral studies with Prof. Yasuo Norikane and Prof. Yoshitaka Hamashima at the National Institute of Advanced Industrial Science and Technology and the University of Shizuoka (Japan) specialized in photoredox catalysis and microwave flow chemistry. In addition to his authorship of 20 articles indexed by SCI which have been cited ~450 times, he has authored a book chapter, a patent, an industrial press release and various blogs/webinars. For a complete list of publications, see: http://www-oc.chemie.uni-regensburg.de/barham/page_417_en.php

https://scholar.google.co.uk/citations?user=fBgXhboAAAAJ&hl=en

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Article Highlight: Photocatalytic intermolecular anti-Markovnikov hydroamination of unactivated alkenes with N-hydroxyphthalimide

Photocatalytic intermolecular anti-Markovnikov hydroamination of unactivated alkenes with N-hydroxyphthalimide

 

Intermolecular olefin hydroamination is an efficient strategy to form C-N bonds and then construct high-value amines. Traditional olefin hydroamination methods mainly provide Markovnikov products. Thus, it is interesting and challenging to realize anti-Markovnikov olefin hydroamination.

In 2019, Yang’s group reported a visible-light-induced strategy to achieve N-OH bond cleavage of strained cyclobutanone oxime, which is able to activate the N-O bond directly to construct various cyano/gemdifluoroalkene-containing scaffolds via synergistic effects between visible light and phosphoranyl radical cation (Org. Lett. 2019, 21, 2658-2662). Recently, this group designed a visible-light photoredox-catalysed hydroamination of unactivated alkenes using N-hydroxyphthalimide (NHPI) to generate anti-Markovnikov product exclusively based on previous work (Scheme 1). The high versatility and mild conditions of this strategy allow a facile access to various amines using cheap and easily available reagents.

Scheme 1 Photocatalytic intermolecular anti-Markovnikov hydroamination of unactivated alkenes with N-hydroxyphthalimide

Cyclohexene 1a and NHPI were chosen as model substrates. Optimization of reaction conditions shows that the highest yield (82%) could be obtained when using [Ir(dFCF3ppy)2dtbbpy]PF6 and P(OEt)3 as catalyst and MeCN as solvent at room temperature in 24 hours. A wide variety of unactivated alkenes could be tolerated, including cyclic and acyclic aliphatic olefins. Moreover, aliphatic olefins substituted with halogen or trimethylsilyl group could also provide the corresponding products in moderate yields (Table 2).

 

Table 2 Substrate Scope of Unactivated Olefinsa

aConditions: olefin 1 (0.6 mmol, 3.0 equiv.), N‑hydroxyphthalimide (0.2 mmol, 1.0 equiv.), P(OEt)3(0.3 mmol, 1.5 equiv.), [Ir(dFCF3ppy)2dtbbpy]PF6 (2 mol%), MeCN (4 mL), 30 w blue LED, rt, argon atmosphere, 24 h, isolated yield.

Scheme 2. Control experiments

To gain mechanistic insights into this reaction, several control experiments were then carried out. Product formation was inhibited, when radical trapping agents such as 2,2,6,6-tetramethyl-1-piperdinyloxy (TEMPO) or benzoyl peroxide(BPO) were added under the standard reaction conditions, suggesting a radical process was involved possibly. On/off experiments demonstrate the corresponding product is formed upon irradiation, as well as in the dark, which supports a chain-propagation-type radical reaction (Scheme 2).

Scheme 3. potential energy surface of the plausible reaction pathway.

 

Furthermore, DFT calculations were performed to understand the catalytic mechanism.Initially, the [Ir(III)]isexcited to *[Ir(III)] under the irradiation of visible light. Then, NHPI and P(OEt)3are able to oxidatively quench *[Ir(III)] via a PCET-mediated activation of O-H bond to afford the corresponding PINO radical. The key PINO radical undergoes a radical addition with P(OEt)3 to deliver phosphoranyl radical I via TS1. Subsequently, N-centred radical intermediate II is formed through β-scission fragmentation of radical I, releasing triethyl phosphate. This step is calculated to possess a Gibbs free energy barrier of 7.8 kcal/mol and is highly irreversible with a driving force as large as 49.5 kcal/mol. In the presence of alkene, a radical addition occurs facilely to generate radical intermediate III. Finally, this resulting radical intermediate III promotes a hydrogen atom transfer from NHPI to deliver the desired product 3a and simultaneously regenerate the PINO radical, which would react with P(OEt)3 to initiate another radical reaction. Notably, this chain-propagation-type mechanism agrees well with our control experiments and Schmidt’s results.
In summary, this group successfully developed a visible-light photoredox-catalysed hydroamination of alkenes using N-hydroxyphthalimide (NHPI) with exclusive anti-Markovnikov selectivity. High synthetic efficiency and mild reaction conditions would endow this protocol with potentials and flexibility in building various aliphatic amines.

Corresponding author

Professor Hua Yang at College of Chemistry and Chemical Engineering Central South University has a great interest in organic synthesis, asymmetric catalysis, visible-light catalysis and total synthesis of chiral drug molecules. Professor Yang developed an excellent organic catalyst-“Hua Cat”. And this patented reagent was commercialized by Sigma-Aldrich, and has been widely applied in asymmetric synthesis.

Hao-Yue Xiang, is an associate professor at College of Chemistry and Chemical Engineering, Central South University. Dr. Xiang received his PhD degree from Shanghai Institute of Materia Medica, Chinese Academy of Sciences and has made great progresses in the construction of heterocyclic compound library and the discovery of lead compounds. Dr Xiang’s current research focus is on fluorine chemistry, boron chemistry and radical chemistry.

Dr Kai Chen, at College of Chemistry and Chemical Engineering, Central South University.mainly work in computational organic chemistry, designof autocatalytic system, and computer-aided drug design. Chen received his PhD at Peking University in 2014, and then moved to South China University of Technology. Since 2019, Chen worked at Central South University.

Peng-Ju Xia, is lecturer of School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University.Xia mainly work inresearch field ofphotocatalytic/electrochemical organic catalysis and and 1, 3-dipole cyclization.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Outstanding Reviewers for Organic Chemistry Frontiers in 2019

We would like to highlight the Outstanding Reviewers for Organic Chemistry Frontiers in 2019, as selected by the editorial team, for their significant contribution to the journal. The reviewers have been chosen based on the number, timeliness and quality of the reports completed over the last 12 months.

We would like to say a big thank you to those individuals listed here as well as to all of the reviewers that have supported the journal. Each Outstanding Reviewer will receive a certificate to give recognition for their significant contribution.

Dr Pablo Ballester, Institute of Chemical Research of Catalonia (ICIQ), ORCID: 0000-0001-8377-6610

Dr Ying-Chun Chen, Sichuan University, ORCID: 0000-0003-1902-0979

Prof Xuefeng Jiang East China Normal University, ORCID: 0000-0002-1849-6572

Dr Shukkoor Muhammed Kondengaden, Georgia State University

Prof Zhan Lu, Zhejiang Universitry, ORCID: 0000-0002-3069-079X

Dr Feng Shi, Jiangsu Normal University, ORCID: 0000-0003-3922-0708

Dr Qiuling Song, Huaqiao Univeristy, ORCID: 0000-0002-9836-8860

Dr Jie Wu, Fudan University, ORCID: 0000-0002-0967-6360

Dr Da-Gang Yu, Sichuan University, ORCID: 0000-0001-5888-1494

Dr Yonghui Zhang, Huazhong University of Science and Technology, ORCID: 0000-0002-7222-2142

We would also like to thank the Organic Chemistry Frontiers board and the organic chemistry community for their continued support of the journal, as authors, reviewers and readers.

 

If you would like to become a reviewer for our journal, just email us with details of your research interests and an up-to-date CV or résumé.  You can find more details in our author and reviewer resource centre

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Jennifer Schomaker joins OCF as Associate Editor

Organic Chemistry Frontiers is delighted to welcome Professor Jennifer Schomaker (University of Wisconsin-Madison, USA) as Associate Editor for the journal.

Biography

Jennifer Schomaker began her research career at Dow Chemical in Organic Chemicals and Polymers, later moving to Agricultural Chemicals Process Research, where she participated in route selection and scale-up campaigns for two new herbicides. After 7 years in industry, she obtained her Ph.D. with Professor Babak Borhan at Michigan State University in 2006 before moving to UC-Berkeley as an NIH postdoctoral fellow under Professors Robert G. Bergman and F. Dean Toste. She joined the University of Wisconsin-Madison in 2009, where she is a full professor.

 

 

 

 

Research Highlights

Her research focuses on new methodologies for preparing stereochemically complex, densely functionalized amines, catalyst-controlled, tunable chemo- and site-selective C-H functionalizations, uncovering new reactivities catalyzed by first-row transition metals, total synthesis of bioactive natural and unnatural products, and development of new bioorthogonal labeling reagents.

Check some of her publications at Royal Society of Chemistry:

Regioselective differentiation of vicinal methylene C–H bonds enabled by silver-catalysed nitrene transfer

Ryan J. Scamp, Bradley Scheffer and Jennifer M. Schomaker

Chem. Commun., 2019,55, 7362-7365

Tunable differentiation of tertiary C–H bonds in intramolecular transition metal-catalyzed nitrene transfer reactions

Joshua R. Corbin and Jennifer M. Schomaker

Chem. Commun., 2017,53, 4346-4349

 

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Arjan W. Kleij joins OCF as Associate Editor

Organic Chemistry Frontiers is delighted to welcome Professor Arjan W. Kleij (Institute of Chemical Research of Catalonia, Spain) as Associate Editor for the journal.

Biography

Arjan W. Kleij received his MSc in 1996 and PhD in 2000 from Utrecht University working on dendrimer- and polymer-supported homogeneous catalysts. In 2000, he moved to industry and worked for more than 3 years at Avantium in its pharmaceutical branch, and later at Hexion as a research scientist. In 2002-2005, he was a postdoc at UAM in Madrid (Spain) and at the University of Amsterdam. In 2006, he moved to the Institute of Chemical Research of Catalonia (ICIQ) and became Group Leader, and was promoted to ICREA Professor in 2011. He is the recipient of a NWO Talent Fellowship and an ICREA junior grant, and recently featured in the author profile section of Angewandte Chemie. Arjan has (co)authored around 180 papers and 4 patent applications with >9600 citations (h-index 55). He is an advisory board member for ChemSusChem and editorial board member for the Journal of CO2 Utilization. He is chair of the Carbon Dioxide Conversion Catalysis (CDCC) conference and the EuGSC-4.

 

Research Highlights

His research is centered on the use of effective and new catalytic solutions (both metal- and organocatalysisorientated) towards the preparation of fine chemicals, pharma-relevant compounds and novel materials based on bio-based polymers. Focuses are on exquisite control over chemo-, regio-, diastereo- and enantio-selectivity features creating new synthetic opportunities of fundamental and industrial interest.

Check some of his publications at Royal Society of Chemistry:

Entropic corrections for the evaluation of the catalytic activity in the Al(III) catalysed formation of cyclic carbonates from CO2 and epoxides

Joan González-Fabra, Fernando Castro-Gómez, W. M. C. Sameera, Gunnar Nyman, Arjan W. Kleij and Carles Bo

Catal. Sci. Technol., 2019,9, 5433-5440

 

Advances in the use of COas a renewable feedstock for the synthesis of polymers

Bruno Grignard, Sandro Gennen, Christine Jérôme, Arjan W. Kleij and Christophe Detrembleur

Chem. Soc. Rev., 2019,48, 4466-4514

Self-assembly of bis-salphen compounds: from semiflexible chains to webs of nanorings

Sergey V. Pyrlin, Nicholas D. M. Hine, Arjan W. Kleij and Marta M. D. Ramos

Soft Matter, 2018,14, 1181-1194

Polystyrene-supported bifunctional resorcinarenes as cheap, metal-free and recyclable catalysts for epoxide/CO2 coupling reactions

Jose, S. Cañellas, M. A. Pericàs and A. W. Kleij

Green Chem., 2017,19, 5488-5493

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Celebration of the 75th birthday of Professor Julius Rebek, Jr.

On October 17-20, 2019, a Symposium on Supramolecular Chemistry in Celebration of Prof. Julius Rebek Jr.’s 75th birthday was held at the University of Shanghai, hosted by Prof. Yang Yu. More than 30 alumni of Professor Rebek presented their research, covering an enormous spread of research inspired by their academic teacher Julius Rebek from supramolecular chemistry to catalysis, biological chemistry up to materials science. At this event a printed version of a themed collection of Organic Chemistry Frontiers dedicated to Professor Julius Rebek on the occassion of his 75th birthday in April 2019 was given to Prof. Rebek by the two guest editors, Pablo Ballester and Frank Würthner (see picture below).

From left to right: Prof. Frank Würthner, Associate Editor of OCF; Prof. Julius Rebek, Jr. with the special issue dedicated to him; Prof. Pablo Ballester, Guest Editor of the special issue; Prof. Yang Yu, Organizer of the Symposium at Shanghai University

 

Read the articles in the themed collection in celebration of the 75th birthday of Professor Julius Rebek, Jr.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Welcome to Issue 14 of Organic Chemistry Frontiers in 2019

Welcome to issue 14 of Organic Chemistry Frontiers for 2019 ! The latest OrgChemFront issue is published online now.

The front cover story, Fischernolides A-D, Four Novel Diterpene-Based Meroterpenoid Scaffolds with Antitumor Activities from Euphorbia fischerian by Wei-Ku Zhang, Jie-Kun Xu and co-authors. The inside cover features a story on Photoredox/rhodium catalysis in C–H activation for the synthesis of nitrogen containing heterocycles by Magnus Rueping and co-authors.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Hot Article in June 2019

Organic Chemistry Frontiers is delighted to share with you the HOT article of June 2019!
You can access this publication for free till 31-Aug-2019 by logging into your free Royal Society of Chemistry publishing personal account (http://pubs.rsc.org).

 

Ligandless nickel-catalyzed transfer hydrogenation of alkenes and alkynes using water as the hydrogen donor
Xiaoping Hu, Gaonan Wang, Chunxiang Qin, Xin Xie, Chunli Zhang, Wei Xu and Yuanhong Liu
Org. Chem. Front., 2019, Advance Article
https://doi.org/10.1039/C9QO00616H

A novel chiral DMAP–thiourea bifunctional catalyst catalyzed enantioselective Steglich and Black rearrangement reactions
Qing-Hua Li, Gui-Shan Zhang, Yu-Hui Wang, Ming-Shun Mei, Xin Wang, Qiang Liu, Xiao-Di Yang, Ping Tian and Guo-Qiang Lin
Org. Chem. Front., 2019, Advance Article
https://doi.org/10.1039/C9QO00691E

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Welcome to Issue 13 of Organic Chemistry Frontiers in 2019

Welcome to issue 13 of Organic Chemistry Frontiers for 2019 ! The latest OrgChemFront issue is published online now.

 

The front cover story, Palladiumcatalyzed regioselective C–H alkynylation of indoles with bromoalkynes in water by Wanqing Wu and co-authors. The inside cover features a story on Trifluoromethyl-substituted selenium ylide: a broadly applicable electrophilic trifluoromethylating reagent by Hangming Ge and Qilong Shen .

 

 

 

 

 

 

 

Follow review type articles are included in current issue:

Developments towards synthesis of N-heterocycles from amidines via C–N/C–C bond formation
Wei Guo, Mingming Zhao, Wen Tan, Lvyin Zheng, Kailiang Tao and Xiaolin Fan

Org. Chem. Front., 2019,6, 2120-2141
https://doi.org/10.1039/C9QO00283A

 

Recent synthetic applications of α-amido sulfones as precursors of N-acylimino derivatives
Enrico Marcantoni, Alessandro Palmieri and Marino Petrini

Org. Chem. Front., 2019,6, 2142-2182
https://doi.org/10.1039/C9QO00196D

 

Metal-catalyzed radical-type transformation of unactivated alkyl halides with C–C bond formation
under photoinduced conditions
Shengqing Ye, Tianyi Xiang, Xiaofang Li and Jie Wu

Org. Chem. Front., 2019,6, 2183-2199
https://doi.org/10.1039/C9QO00272C

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Qian Zhang joins OCF as Associate Editor

Organic Chemistry Frontiers is delighted to welcome Professor Qian Zhang (Northeast Normal University, China) as Associate Editor for the journal.

 

Biography

Qian Zhang is a Professor in the Department of Chemistry at Northeast Normal University, Changchun, China. She obtained her BS and MS degrees from Department of Chemistry, Northeast Normal University, and PhD degree from Changchun Institute of Applied Chemistry, Chinese Academy of Sciences under the supervision of Professor Lixiang Wang in the research field of organic light emitting materials. Then she spent half a year as a visiting scholar in the University of Sydney, Australia. She has been teaching and doing research at Northeast Normal University for more than 20 years. She received several awards including Thieme Chemistry Journals Award and Changchun Excellent Female Contributors Award in 2014.

 

 

 

 

 

Research Highlights

Her research focuses on the field of synthetic methodology mostly mediated by transition metals, aimed to address key unmet challenges in contemporary organic synthesis, with an emphasis on asymmetric catalysis. Current research topics include: 1) to develop novel synthetic methodologies focusing on the new strategy for C-N bond formation and the discovery of new amination reagents; 2) strain release promoted and inspired new reaction.

 

Check some of her publications at Royal Society of Chemistry:

Enantioselective and site-specific copper-catalyzed reductive allyl–allyl cross-coupling of allenes

Guoxing Xu, Bin Fu, Haiyan Zhao, Yanfei Li, Ge Zhang, Ying Wang, Tao Xiong and Qian Zhang

Chem. Sci., 2019, 10, 1802-1806

Pd-Catalyzed carboannulation of γ,δ-alkenyl oximes: efficient access to 5-membered cyclic nitrones and dihydroazines

Baozhen Sun, Shuang Liu, Mengru Zhang, Jinbo Zhao and Qian Zhang

Org. Chem. Front., 2019, 6, 388-392

Copper-catalyzed oxidative amidation of α,β-unsaturated ketones via selective C–H or C–C bond cleavage

Tony Wheellyam Pouambeka, Ge Zhang, Guang-Fan Zheng, Guo-Xing Xu, Qian Zhang, Tao Xiong and Qian Zhang

Org. Chem. Front., 2017,4, 1420-1424

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)