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Scientific Reports Volume 6, Article Number: 20068 (2016) Cite this article

Ready-to-use natural α-amino acids are one of the most attractive and versatile components in nature for the synthesis of natural products and biomolecules. Peptides and N-heterocycles exhibit various biological and pharmaceutical functions. The combination of amino acids or peptides with N-heterocycles provides unlimited potential for screening and discovering a variety of biologically active molecules. However, it is a huge challenge to install amino acids or peptides on N-heterocycles by forming carbon-carbon bonds under mild conditions. In this article, 18 N-protected α-amino acids and 3 peptides are assembled by coupling N-protected α-amino acids and peptide active esters with substituted 2-isocyanobiphenyls at room temperature with the aid of visible light. On phenanthridine derivatives. In addition, using similar procedures, N-Boc-proline residues were successfully combined with oxindole derivatives. The method has simple scheme, mild reaction conditions, fast reaction speed and high efficiency, making it an important strategy for synthesizing a variety of molecules containing amino acids and peptide fragments.

Amino acids are one of the most attractive and versatile components in the synthesis of natural products and biomolecules, and peptides are very important in today’s drug discovery programs2. On the other hand, N-heterocycles are ubiquitous in natural products and biologically active molecules, and they are designated as privileged structures in drug discovery, because the N-heterocycle moiety generally exhibits improved solubility and can promote salt-forming properties , Both of which are for oral absorption and bioavailability4,5,6. The combination of amino acids or peptides and N-heterocyclic compounds provides a good opportunity for screening and discovering a variety of biologically active substances. Among the previously available strategies, common conjugation is usually carried out through the formation of amides (Figure 1a), carbon-heteroatom bonds (Figure 1b). Conjugation through the formation of CC bonds has been developed through the use of olefin metathesis7 and transition metal-catalyzed cross-coupling8 strategies. However, due to the inherent structural characteristics of amino acids and peptides, the connection of CC bonds is still a huge and urgent challenge for chemists. On the other hand, the transition metal-catalyzed decarboxylation strategy used to form CC bonds provides some valuable reactions in organic synthesis9,10,11,12, such as Heck-type reactions 13,14, allylation 15, redox Neutral cross-coupling reactions 16, 17 and oxidative arylation 18, 19. However, the reaction usually requires high temperatures and stronger bases, and is intolerant to amino acids and peptides. Recently, visible light photoredox catalysis has attracted a lot of attention, and it has become a powerful activation protocol in new chemical transformations20,21,22,23,24,25,26,27. In addition, some decarboxylation couplings with the formation of CC bonds have been developed 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39. As far as we know, the conjugation between amino acids or peptides and N-heterocycles is limited by the formation of CC bonds under mild conditions and with the aid of visible light. Here, we report the efficient installation of amino acids and peptides on phenanthridine and oxindole derivatives with the aid of visible light at room temperature (Figure 1c).

The design of installing amino acids and peptides on the N-heterocycle.

(a) The previous conjugation via an amide bond. (b) Previous conjugation via carbon-heteroatom bond. (c) Conjugation through the formation of carbon-carbon bonds with the aid of visible light.

Since 2-isocyanobiphenyls are effective free radical receptors40,41,42, we first chose them as partners of N-protected amino acid active esters under visible light photoredox catalysis. As shown in Table 1, our research on the optimal conditions started with the model reaction of N-Boc-Pro-OPht (Pht = phthalimide) (1r) with isonitrile 2a. With 1.0 mol% [Ru(bpy)3]Cl2 as the photoredox catalyst, 1 equivalent of diisopropylethylamine (DIPEA) (relative to the amount of 2a) as the reducing agent, DMF as the solvent, and the reaction at room temperature under an argon atmosphere 2 hours (entry 1), the conversion of 3r was 86% (determined by 1H NMR, using trichloroethylene as the internal standard). When 0.4 equivalent of DIPEA was used, the yield decreased (entry 2), but the addition of 1.2 equivalents of K2CO3 as a base greatly promoted their reactivity (entry 3). In the presence of 0.2 equivalent DIPEA (entry 4) or absence of DIPEA (entry 5), the production decreases. Other tertiary amines (entries 6 and 7) were screened and they are not as good as DIPEA. We studied Na2CO3, Cs2CO3, and NaHCO3 as bases (items 8-10), and the results showed that K2CO3 is a suitable base (compare items 3, 8-10). The influence of solvents was studied and DMF provided the best results (compare items 3, 11-13). The reaction in an aqueous medium (DMF/H2O = 9:1) was also tried and provided a yield of 92% (entry 14). When [fac-Ir(ppy)3] was used as a photoredox catalyst, only 79% conversion was found (entry 15). When the system was exposed to air, no reaction was observed (entry 16). The reaction proceeds well under the irradiation of blue LEDs (entry 17). This reaction does not work in the absence of light (entry 18).

After obtaining the optimized conditions assisted by visible light, we tested the decarboxylation coupling of various N-protected amino acid active esters (1) and substituted 2-isocyanobiphenyls (2) to study the substrate range of the reaction. As shown in Figure 2, the active esters of six neutral amino acids including glycine, alanine, valine, leucine, isoleucine and phenylalanine provide high yields (see 3a-f ). The N,O-protected amino acid active ester with hydroxyl on the side chain was tested (see 3g-i). The yield of N-Boc-Ser(OBut)-OPht was lower because of the appearance of unknown by-products (see 3h) And N-Boc-Tyr(OMe)-OPht and N-Boc-Thr(OBut)-OPht provide satisfactory results (see 3g and 3i). N-Boc-Met-OPht is a good substrate, and it provides the target product 3j with a yield of 93%. N, N'-Bis(Boc)-protected Lys-OPht and Trp-OPht show high reactivity (see 3k and 3l). Two active esters of acidic amino acids (aspartic acid and glutamic acid) provide good yields after esterification of the carboxyl group on the side chain with methanol or benzyl alcohol (see 3m and 3n). N, N'-protected asparagine and glutamine active esters provide 3o and 3p in 67% and 75% yields, respectively. N-Boc Pipecoline acid active ester was used as the substrate and showed good results (see 3q). We tried another N-protecting group, benzyloxycarbonyl (Cbz) and N-Cbz-Pro-OPht, which showed similar reactivity to N-Boc-Pro-OPht (see 3r and 3s). Unfortunately, the active esters of three natural amino acids, including cysteine, histidine and arginine, will produce some by-products due to side reactions on the side chains of amino acids under current photo-redox conditions. We also explored the range of sterically hindered substituted 2-isocyanobiphenyls and isonitriles, providing lower yields (see 3u and 3ab). Visible light photoredox decarboxylation coupling shows resistance to some functional groups, including amide, ether (see 3g, 3h, 3i and 3y), thioether (3j), ester (see 3m and 3n), C-Cl bond (See 3z, 3aa and 3ab) and CF3 (see 3ac). It is worth noting that the resulting product contains amino acid residues. After removing the protective groups on the amino acid residues, further derivatization is an easy task. Therefore, the above results provide opportunities for the construction of different molecules. In addition, phenanthridine is present in a variety of naturally-occurring alkaloids 43, 44, 45, and shows a variety of biological and pharmaceutical activities 46, 47. This method provides a convenient, effective and practical scheme for the synthesis of phenanthridine.

The range of substrates bound by N-protected amino acids and phenanthridine*.

*Reaction conditions: Under Ar atmosphere and visible light irradiation, N-protected amino acid-OPht (1) (0.45 mmol for the synthesis of 3a-p; 0.30 mmol for the synthesis of others), substituted 2-isocyanobiphenyl ( 2) (0.15 mmol), [Ru(bpy)3]Cl2 (1.5 μmol), DIPEA (0.06 mmol), K2CO3 (0.18 mmol), DMF (2.0 mL), temperature (rt, ~25 oC), time (1.5 –6 h)) in a sealed Schlenk tube. †Separated yield. Boc = tert-butoxycarbonyl. Bzl = benzyl. Cbz = benzyloxycarbonyl.

Inspired by the above-mentioned excellent results, we extended the range of substrates to N-Boc-peptide active esters. As shown in Figure 3, the dipeptide derivative Boc-Gly-Leu-OPht (1t) reacts with 2a in CH2Cl2 and DMF (2.0mL, CH2Cl2/DMF = 5:1) (Note: Active ester cannot be dissolved well in Fully DMF) (Figure 3a). In addition, we tried to decarboxylate the tripeptide Boc-Gly-Gly-Leu-OPht (1u) and the pentapeptide Boc-Gly-Gly-Gly-Gly-Met-OPht (1v) with 2a under the same conditions to obtain 3ae And 3af with 68% and 69% yields respectively (Figure 3b, c). The above results indicate that Boc-protected peptide active esters are also effective free radical precursors for photoredox catalysis.

The combination of N-Boc peptide and 8-methylphenanthridine with the aid of visible light.

In order to explore the mechanism of this combination, the free radical trapping agent 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) was added to the N-Boc-Pro-OPht (1r) and isonitrile As shown in Figure 2a in the reaction system, the reaction is completely inhibited, which indicates that the reaction may involve free radical intermediate processes. Therefore, based on the above results and previous references 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, a reasonable mechanism for visible light photoredox synthesis of phenanthridine is proposed in Figure 4, 31, 32, 33, 34, 35, 36, 37, 38, 39. Ru(bpy)32 is irradiated with visible light to obtain an excited state [Ru (bpy)32]*. The light-excited catalyst is reduced by DIPEA to form Ru(bpy)3, where DIPEA forms I. 1 and Ru(bpy)3 produce II regeneration catalyst Ru(bpy)32, and then eliminate the phthalimide anion (III) from II to provide carboxyl group IV, and release carbon dioxide in IV to produce α-amino group V. The addition of V to substituted 2-isocyanobiphenyl (2) generates imino group VI, the intramolecular hemolytic aromatic substitution of VI generates group intermediate VII, and oxidation VII with I generates cation VIII, which regenerates DIPEA. Finally, the deprotonation of VIII in the presence of a base produces the target product (3).

A rational mechanism for installing N-protected amino acids and peptides on phenanthridine with the aid of visible light.

We next explored the synthesis of oxindole derivatives through the use of N-protected amino acid active esters under visible light photoredox catalysis. As shown in Figure 5, under optimized reaction conditions, the decarboxylation coupling of N-Boc-Pro-OPht and N-alkyl-N-phenylalkylacrylamide provides the corresponding oxindole in a moderate yield. As we all know, oxindole is widely found in natural products with unique biological activity. They are the privileged scaffolds for the design and discovery of drugs48,49,50. Therefore, this method provides a new method for synthesizing oxindole derivatives.

Installation of N-Boc proline residues on the indole oxide with the aid of visible light.

In summary, we have developed an effective model for installing N-protected α-amino groups and peptide residues on N-heterocycles through the formation of CC bonds with the assistance of photocatalyst [Ru(bpy)3]Cl2 and visible light. Eighteen N-protected amino acids and three peptide active esters are used. The α-amino or peptide radicals generated by the photo-redox are captured by substituted 2-isocyanobiphenyl or N-alkyl-N-phenylalkylacrylamide at room temperature, and the product has a good yield. Biological and pharmaceutical active phenanthridine and oxindole derivatives. The generation of reactive free radicals under mild photocatalytic conditions can reduce the incidence of adverse side reactions caused by N-protected amino acids and peptide derivatives. The most important thing is that the obtained product contains amino acids and peptide fragments, and their further modification can provide different molecules after the protective groups on the amino acids and peptide fragments. The current discovery paves the way for the future synthesis of biological and pharmaceutical molecules containing amino acids and peptide fragments. We believe that the current strategy will be widely used in organic synthesis.

[Ru(bpy)3]Cl2 (1.5 μmol, 1.2 mg), 1 (0.45 mmol for the synthesis of 3a--p; 0.30 mmol for the synthesis of others), 2 (0.15 mmol) or 4 (0.15 mmol), DIPEA ( 0.06 mmol, 10 μL) and K2CO3 (0.18 mmol, 25 mg) were added to a 25 mL Schlenk tube containing DMF (2.0 mL) or a mixed solvent of CH2Cl2 and DMF (2.0 mL, CH2Cl2/DMF (5:1)) and argon Degas the tube for more than 5 minutes. Seal the tube and irradiate it with a 40 W fluorescent lamp (approximately 2 cm from the light source). After the substrate was completely converted (monitored by TLC), the reaction mixture was diluted with 20 L of EtOAc, and the solution was filtered by flash chromatography. The filtrate was evaporated with a rotary evaporator, and the residue was purified by silica gel column chromatography to obtain the desired products (3a-af and 5a-e).

How to cite this article: Jin, Y. et al. Install amino acids and peptides on the N-heterocycle with the aid of visible light. science. Rep. 6, 20068; doi: 10.1038/srep20068 (2016).

Blaskovich, MA Handbook of Amino Acid Synthesis: General Routes for Amino Acid Synthesis, 1st edition; Oxford University Press: New York (2010).

Noisier, AFM & Brimble, MA CH Functionalization in the synthesis of amino acids and peptides. Chemical Revision 114, 8775–8806 (2014).

DeSimone, RW, Currie, KS, Mitchell, SA, Darrow, JW & Pippin, DA Privileged structure: applications in drug discovery. comb. Chemical high-throughput screen. 7, 473–493 (2004).

Leeson, PD and Springthorpe, B. The impact of drug-like concepts on medicinal chemistry decisions. Nat. Rev. Drug Discovery 6, 881–890 (2007).

Meanwell, NA improves drug candidates through design: focusing on physicochemical properties as a means to improve compound handling and safety. Chemical reservoir poison. 24, 1420–1456 (2011).

Ritchie, TJ, Macdonald, SJF, Young, RJ & Pickett, SD The influence of the number of aromatic rings on the developability of compounds: further understanding by examining the types of carbocyclic, heteroaromatic and aliphatic rings. Drug Discovery Today 16, 164–171 (2011).

Lin, YA, Boutureira, O., Lercher, L., Bhushan, B., Paton, RS & Davis, BG The selenoallylselenocysteine ​​in protein is obtained by chemical means, and rapid cross metathesis is used for reversibility Protein modification. J. Am Chemical Society. 135, 12156–12159 (2013).

PubMed PubMed Central CAS Google Scholar 

Gao, Z., Gouverneur, V. & Davis, BG Enhanced aqueous Suzuki-Miyaura coupling allows site-specific peptide 18F labeling. J. Am Chemical Society. 135, 13612–13615 (2013).

PubMed PubMed Central CAS Google Scholar 

Weaver, JD, Recio, A. III, Grenning, AJ & Tunge, JA Transition metal catalyzed decarboxylation and benzylation reactions. Chemistry Rev. 111, 1846-1913 (2011).

PubMed PubMed Central CAS Google Scholar 

Rodriguez, N. & Gooβen, LJ Decarboxylation coupling reaction: a modern strategy for CC bond formation. Chemical society. Rev. 40, 5030–5048 (2011).

Dzik, WI, Lange, PP & Gooβen, LJ Carboxyates as a source of carbon nucleophiles and electrophiles: a comparison of decarboxylation and decarbonylation pathways. Chemical science. 3, 2671–2678 (2012).

Goonβen, LJ, Rodríguez, N. & Gooβenn, K. Carboxylic acids are used as substrates in homogeneous catalysis. Angie. Chemistry, international. Ed. 47, 3100–3120 (2008).

Myers, AG, Tanaka, D. & Mannion, MR Development of decarboxylation palladium reaction and its application in Heck-type olefination of aromatic carboxylates. J. Am Chemical Society. 124, 11250-11251 (2002).

Forgione, P., Brochu, MC, Stonge, M., Thesen, KH, Bailey, MD & Bilodeau, F. Unexpected intermolecular Pd-catalyzed cross-coupling reaction, using heteroaromatic carboxylic acid as coupling partner. J. Am Chemical Society. 128, 11350-11351 (2006).

Rayabarapu, DK & Tunge, JA catalyzed decarboxylation sp-sp3 coupling. J. Am Chemical Society. 127, 13510–13511 (2005).

Gooβen, LJ, Deng, G. & Levy, LM Synthesize biaryl compounds through catalytic decarboxylation coupling. Science 313, 662–664 (2006).

Gooβen, LJ, Rodríguez, N., Melzer, B., Linder, C., Deng, G. & Levy, LM Synthesize biaryl through decarboxylation coupling of aromatic carboxylate and aryl halide catalyzed by Pd. J. Am Chemical Society. 129, 4824–4833 (2007).

Wang, C., Piel, I. and Glorius, F. Palladium-catalyzed direct intramolecular arylation of benzoic acid via tandem decarboxylation/CH activation. J. Am Chemical Society. 131, 4194–4195 (2009).

Goonβen, LJ, Rodríguez, N., Lange, PP & Linder, C. Decarboxylation cross-coupling of aryl tosylate and aromatic carboxylate. Angie. Chemistry, international. Ed. 49, 1111–1114 (2010).

Prier, CK, Rankic, DA & MacMillan, DWC Visible light photoredox catalysis of transition metal complexes: applications in organic synthesis. Chemistry Rev. 113, 5322–5363 (2013).

PubMed PubMed Central CAS Google Scholar 

Yoon, TP, Ischay, MA & Du, J. Visible light photocatalysis as a more environmentally friendly photochemical synthesis method. Nat. Chemistry 2, 527–532 (2010).

Narayanam, JMR & Stephenson, CRJ Visible light photoredox catalysis: applications in organic synthesis. Chemical society. Revision 40, 102–113 (2011).

Zeitler, K. Visible light redox catalysis. Angie. Chemistry, international. Ed. 48, 9785–9789 (2009).

Shi, L. & Xia, W. The photo-redox functionalization of the CH bond adjacent to the nitrogen atom. Chemical society. Revision 41, 7687–7697 (2012).

Xuan, J. & Xiao, W.-J. Visible light photo-redox catalysis. Angie. Chemistry, international. Ed. 51, 6828–6838 (2012).

Hari, DP & König, B. Photocatalytic Melvin arylation: the classic reaction of aryl diazonium salts under new light. Angie. Chemistry, international. Ed. 52, 4734–4743 (2013).

Chemical photocatalysis (Editor: König, B.), De Gruitt, Stuttgart (2013).

DiRocco, DA, Dykstra, K., Krska, S., Vachal, P., Conway, DV & Tudge, M. The late functionalization of biologically active heterocycles is achieved through photoredox catalysis. Angie. Chemistry, international. Ed. 53, 4802–4806 (2014).

Lang, SB, O'Nele, KM & Tunge, JA decarboxylates aminoalkanoic acids and esters through dual catalysis. J. Am Chemical Society. 136, 13606–13609 (2014).

PubMed PubMed Central CAS Google Scholar 

Schnermann, MJ & Overman, LE promoted the concise synthesis of (-)-aplyviolene through strategic tertiary free radical conjugate addition. Angie. Chemistry, international. Ed. 51, 9576-9580 (2012).

Lackner, GL, Quasdorf, KW and Overman, LE construct quaternary carbon directly from tertiary alcohols through photoredox-catalyzed cleavage of tertiary alkyl N-phthaloyl oxalate. J. Am Chemical Society. 135, 15342–15345 (2013).

Yang, J., Zhang, J., Qi, L., Hu, C. & Chen, Y. Visible light-induced chemoselective reductive decarboxylation under compatible conditions of biomolecules. Chemical community. 51, 5275–5278 (2014).

Leung, JCT, Chatalova-Sazepin, C., West, JG, Rueda-Becerril, M., Paquin, J.-F. & Sammis, GM Photofluorine decarboxylation of 2-aryloxy and 2-aryl carboxylic acids. Angie. Chemistry, international. Ed. 51, 10804–10807 (2012).

Liu, J., Liu, Q., Yi, H., Qin, C., Bai, R., Qi, X., Lan, Y. & Lei, A. Visible light-mediated alpha decarboxylation/oxidative amidation- Keto acids and amines use O2 under mild reaction conditions. Angie. Chemistry, international. Ed. 53, 502–506 (2014).

Rueda-Becerril, M., Mahé, O., Drouin, M., Majewski, MB, West, JG, Wolf, MO, Sammis, GM & Paquin, J.-F. Direct formation of CF bonds using photoredox catalysis. J. Am Chemical Society. 136, 2637–​​2641 (2014).

Noble, A. & MacMillan, DWC Photoredox vinylation of α-α-amino acids and N-arylamines. J. Am Chemical Society. 136, 11602–11605 (2014).

PubMed PubMed Central CAS Google Scholar 

Chu, L., Ohta, C., Zuo, Z. & MacMillan, DWC Carboxylic acid as a traceless activating group added by conjugate: (±)-pregabalin three-step synthesis. J. Am Chemical Society. 136, 10886–10889 (2014).

PubMed PubMed Central CAS Google Scholar 

Zuo, Z. & MacMillan, DWC Decarboxylation of α-amino acids through photoredox catalysis: a one-step conversion of biomass to drug pharmacophores. J. Am Chemical Society. 136, 5257–5260 (2014).

PubMed PubMed Central CAS Google Scholar 

Zuo, Z., Ahneman, DT, Chu, L., Terrett, JA, Doyle, AG & MacMillan, DWC Combining photoredox and nickel catalysis: the coupling of α-carboxyl sp3-carbon and aryl halide. Science 345, 437–440 (2014).

ADS PubMed PubMed Central CAS Google Scholar 

Ryu, I., Sonoda, N. & Curran, DP The tandem free radical reaction of carbon monoxide, isonitrile and other reagent equivalents of the twin radical acceptor radical precursor synthon. Chemistry Rev. 96, 177–194 (1996).

Tobisu, M., Koh, K., Furukawa, T. & Chatani, N. Oxidative cyclization of 2-isocyanobiphenyl with organoboron reagent, modular synthesis of phenanthridine derivatives. Angie. Chemistry, international. Ed. 51, 11363–11366 (2012).

Jiang, H., Cheng, Y., Wang, R., Zheng, M., Zhang, Y. & Yu, S. Synthesis of 6-alkylated phenanthridine derivatives using photoredox neutral eosinophilic isocyanide insertion Things. Angie. Chemistry, international. Ed. 52, 13289–13292 (2013).

Synthesis and synthesis of Nakanishi, T., Masuda, A., Suwa, M., Akiyama, Y., Hoshino-Abe, N. & Suzuki, M. NK109, 7-OH benzo[c] phenanthridine alkaloid derivatives It evaluates cytotoxicity and anti-reduction properties. Biological tissue. medicine. Chemical Wright. 10, 2321–2323 (2000).

Nakanishi, T., Suzuki, M., Saimoto, A. and Kabasawa, T. Structural considerations of NK109 (an anti-tumor benzo[c]phenanthridine alkaloid). J. Nat. product. 62, 864–867 (1999).

Nakanishi, T. & Suzuki, M. Revised the structure of Fagaridin based on the comparison of the UV and NMR data of the synthesized compound. J. Nat. product. 61, 1263–1267 (1998).

Denny, WA Acridine derivatives as chemotherapeutics. Curry medicine. Chemistry 9, 1655–1665 (2002).

Ishikawa, T. Benzo[c] Phenanthridinine and its anti-tuberculosis activity. medicine. Reservoir Rev. 21, 61-72 (2001).

Galliford, CV and Scheidt, KA Pyrrolidinyl-spirocyclic indole natural product as inspiration for the development of potential therapeutic agents. Angie. Chemistry, international. Ed. 46, 8748–8758 (2007).

Le Tourneau, C., Raymond, E. and Faivre, S. Sunitinib: a new type of tyrosine kinase inhibitor. A brief review of its therapeutic potential in the treatment of kidney cancer and gastrointestinal stromal tumor (GIST). that. clinical. Risk Management. 3, 341–348 (2007).

PubMed PubMed Central CAS Google Scholar 

Kitamura, H., Kato, A. and Esaki, T. AG-041R is a new indoline-2-one derivative that can induce systemic cartilage hyperplasia in rats. EUR. J. Pharmacology. 418, 225–230 (2001).

This work was funded by the National Natural Science Foundation of China (approval number: 21172128, 21372139, and 2121062), the Ministry of Science and Technology of China (approval number: 2012CB722605) and the Shenzhen Municipal Government (approval number: SZSITIC CXB2101010).

Department of Chemistry, Key Laboratory of Bioorganophosphorus Chemistry and Chemical Biology, Ministry of Education, Tsinghua University, Beijing, 100084

Yunhe Jin, Min Jiang, Hui Wang & Hua Fu

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YJ and HF conceived the subject, YJ, MJ and HW conducted experimental work, YJ and HF analyzed the results, and YJ and HF co-authored the manuscript.

The author declares that there are no competing economic interests.

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Jin, Y., Jiang, M., Wang, H. etc. Install amino acids and peptides on the N-heterocycle with the aid of visible light. Scientific Report 6, 20068 (2016). https://doi.org/10.1038/srep20068

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