Advertisement

Functionalization of Aromatic N-Heterocycles with C(sp3)–H Sources via CDC Reactions

Chapter
  • 394 Downloads

Abstract

Nitrogen-containing heterocycles are a ubiquitous nature and synthetic compounds having wide spectrum of activities, which has found applications in various industrial fields. Among a variety of synthetic approaches toward substituted N-heterocycles, C(sp2)–H functionalization represents the most rapid and convenient transformation. In this review, we concentrated attention on the methods of construction of new C–C bonds via direct coupling of N-heterocyclic C(sp2)–H with C(sp3)–H derivatives, which is called cross-dehydrogenative coupling and satisfied the requirements of “atom economy” and “green chemistry.” Alkanes, ethers, amines and amides, methylarenes, etc., were involved in the oxidative process with N-heterocyclic compound.

Keywords

CDC reactions Nitrogen heterocycles Functionalization 

Abbreviation

Ar

Aryl

BHP

2,6-Di-tert-butyl-4-methylphenol

Binap

2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl

BPO

Benzoyl peroxide

CCHE

Cross-coupling hydrogen evolution

CDC

Cross-dehydrogenative coupling

DCDC

Double cross-dehydrogenative coupling

CFL

Compact fluorescent lamp

DCE

1,2-Dichloroethane

DCP

Dicumyl peroxide

DDQ

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone

DG

Directing group

DMA

N,N-Dimethylacetamide

DMF

N,N-Dimethylformamide

DTBP

Di-tert-butyl peroxide

HAT

Hydrogen atom transfer

LED

Light-emitting diode

PG

Protecting group

Ph

Phenyl

PIFA

Phenyliodine bis-(trifluoroacetate)

PMP

p-Methoxyphenyl

Py-GC-MS

Pyrolysis–gas chromatography–mass spectrometry

RT

Room temperature

SET

Single-electron transfer

TBAB

Tetra-n-butylammonium bromide

TBAI

Tetra-n-butylammonium iodide

TBPB

Tert-butyl perbenzoate

TEMPO

(2,2,6,6-Tetramethylpiperidin-1-yl)oxidanyl

TFA

Trifluoroacetic acid

THF

Tetrahydrofuran

THIQ

Tetrahydroisoquinoline

TMU

N,N,N′,N′-tetramethylurea

Tol

Tolyl

TsOH

p-Toluenesulfonic acid

Notes

Acknowledgments

This work was supported by the Russian Science Foundation (project #18-13-00365).

References

  1. 1.
    Minisci F (1976) Recent aspects of homolytic aromatic substitutions. Top Curr Chem 62:1–48PubMedCrossRefPubMedCentralGoogle Scholar
  2. 2.
    Minisci F, Vismara E, Fontana F (1989) Recent developments of free-radical substitutions of heteroaromatic bases. Heterocycles 28:489–519CrossRefGoogle Scholar
  3. 3.
    Minisci F, Fontana F, Vismara E (1990) Substitutions by nucleophilic free radicals: a new general reaction of heteroaromatic bases. J Heterocycl Chem 27:79–96CrossRefGoogle Scholar
  4. 4.
    Punta C, Minisci F (2008) Minisci reaction: a Friedel-Crafts type process with opposite reactivity and selectivity. Selective homolytic alkylation, acylation, carboxylation and carbamoylation of heterocyclic aromatic bases. Trends Heterocycl Chem 13:1–68Google Scholar
  5. 5.
    Duncton MAJ (2011) Minisci reactions: versatile CH-functionalizations for medicinal chemists. Med Chem Commun 2:1135–1161CrossRefGoogle Scholar
  6. 6.
    Li JJ (2014) Minisci reaction. In: Name reactions, 5th edn. Springer International Publishing, pp 361–362Google Scholar
  7. 7.
    Minisci F, Vismara E, Morini G, Fontana F, Levi S, Serravalle M, Giordano C (1986) Polar effects in free-radical reactions. selectivity and reversibility in the homolytic benzylation of protonated heteroaromatic bases. J Org Chem 51:476–479CrossRefGoogle Scholar
  8. 8.
    Citterio A, Gentile A, Minisci F, Serravalle M, Ventura S (1984) Polar effects in free-radical reactions. Carbamoylation and α-N-amidoalkylation of heteroaromatic bases by amides and hydroxylamine-O-sulfonic acid. J Org Chem 49:3364–3367CrossRefGoogle Scholar
  9. 9.
    Deng G, Li C-J (2009) Sc(OTf)3-catalyzed direct alkylation of quinolines and pyridines with alkanes. Org Lett 11:1171–1174PubMedCrossRefPubMedCentralGoogle Scholar
  10. 10.
    Deng G, Ueda K, Yanagisawa S, Itami K, Li C-J (2009) Coupling of nitrogen heteroaromatics and alkanes without transition metals: a new oxidative cross-coupling at C–H/C–H bonds. Chem Eur J 15:333–337CrossRefGoogle Scholar
  11. 11.
    Antonchick AP, Burgmann L (2013) Direct selective oxidative cross-coupling of simple alkanes with heteroarenes. Angew Chem Int Ed 52:3267–3271CrossRefGoogle Scholar
  12. 12.
    Xia R, Niu H-Y, Qu G-R, Guo H-M (2012) CuI controlled C–C and C–N bond formation of heteroaromatics through C(sp3)–H activation. Org Lett 14:5546–5549PubMedCrossRefPubMedCentralGoogle Scholar
  13. 13.
    Wang D-C, Xia R, Xie M-S, Qu G-R, Guo H-M (2016) Synthesis of cycloalkyl substituted purine nucleosides via a metal-free radical route. Org Biomol Chem 14:4189–4193PubMedCrossRefPubMedCentralGoogle Scholar
  14. 14.
    Faisca Phillips AM, Pombeiro AJL (2018) Recent developments in transition metal-catalyzed cross-dehydrogenative coupling reactions of ethers and thioethers. ChemCatChem 10:3354–3383CrossRefGoogle Scholar
  15. 15.
    Lakshman MK, Vuram PK (2017) Cross-dehydrogenative coupling and oxidative-amination reactions of ethers and alcohols with aromatics and heteroaromatics. Chem Sci 8:5845–5888PubMedPubMedCentralCrossRefGoogle Scholar
  16. 16.
    Lai M, Li Y, Wu Z, Zhao M, Ji X, Liu P, Zhang X (2018) Synthesis of alkyl-substituted pyrazine N-oxides by transition-metal-free oxidative cross-coupling reactions. Asian J Org Chem 7:1118–1123CrossRefGoogle Scholar
  17. 17.
    Yang Q, Li S, Wang J (Joelle) (2018) Cobalt-catalyzed cross-dehydrogenative coupling of imidazo[1,2-a]pyridines with isochroman using molecular oxygen as the oxidant. Org Chem Front 5:577–581Google Scholar
  18. 18.
    Jiang H, Xie J, Lin A, Cheng Y, Zhu C (2012) The Au(III)-catalyzed coupling reactions between alcohols and N-heterocycles via C–H bond activation. RSC Adv 2:10496–10498CrossRefGoogle Scholar
  19. 19.
    Adib M, Pashazadeh R, Rajai-Daryasarei S, Kabiri R, Gohari SJA (2016) Transition-metal-free acylation of quinolines and isoquinolines with arylmethanols via oxidative cross-dehydrogenative coupling reactions. Synlett 27:2241–2245CrossRefGoogle Scholar
  20. 20.
    Wan M, Lou H, Liu L (2015) C1-benzyl and benzoyl isoquinoline synthesis through direct oxidative cross-dehydrogenative coupling with methyl arenes. Chem Commun 51:13953–13956CrossRefGoogle Scholar
  21. 21.
    Shi X, Zhang F, Luo W-K, Yang L (2017) Oxidant-triggered C1-benzylation of isoquinoline by iodine–catalyzed cross-dehydrogenative-coupling with methylarenes. Synlett 13:494–498Google Scholar
  22. 22.
    Ali W, Behera A, Guin S, Patel BK (2015) Regiospecific benzoylation of electron-deficient N-heterocycles with methylbenzenes via a Minisci-type reaction. J Org Chem 80:5625–5632PubMedCrossRefPubMedCentralGoogle Scholar
  23. 23.
    Kianmehr E, Faghih N, Khan KM (2015) Palladium-catalyzed regioselective benzylation–annulation of pyridine N-oxides with toluene derivatives via multiple C-H bond activations: benzylation versus arylation. Org Lett 17:414–417PubMedCrossRefPubMedCentralGoogle Scholar
  24. 24.
    Kianmehr E, Gholamhosseyni M (2018) Visible-light-promoted copper-catalyzed regioselective benzylation of pyridine N-oxides versus thermal acylation reaction with toluene derivatives. Eur J Org Chem 2018:1559–1566CrossRefGoogle Scholar
  25. 25.
    Wan L, Qiao K, Sun XN, Di ZC, Fang Z, Li ZJ, Guo K (2016) Benzylation of heterocyclic N-oxides via direct oxidative cross-dehydrogenative coupling with toluene derivatives. New J Chem 40:10227–10232CrossRefGoogle Scholar
  26. 26.
    Zhang Y, Feng J, Li C-J (2008) Palladium-catalyzed methylation of aryl C–H bond by using peroxides. J Am Chem Soc 130:2900–2901PubMedCrossRefPubMedCentralGoogle Scholar
  27. 27.
    Li G, Yang S, Lv B, Han Q, Ma X, Sun K, Wang Z, Zhao F, Lv Y, Wu H (2015) Metal-free methylation of a pyridine N-oxide C–H bond by using peroxides. Org Biomol Chem 13:11184–11188PubMedCrossRefPubMedCentralGoogle Scholar
  28. 28.
    Guo S, Li Y, Wang Y, Guo X, Meng X, Chen B (2015) Iron-catalyzed cross dehydrogenative coupling (CDC) of indoles and benzylic C–H bonds. Adv Synth Catal 357:950–954CrossRefGoogle Scholar
  29. 29.
    Zhang H-J, Su F, Wen T-B (2015) Copper-catalyzed direct C2-benzylation of indoles with alkylarenes. J Org Chem 80:11322–11329PubMedCrossRefPubMedCentralGoogle Scholar
  30. 30.
    Sambiagio C, Schönbauer D, Blieck R, Dao-Huy T, Pototschnig G, Schaaf P, Wiesinger T, Zia MF, Wencel-Delord J, Besset T, Maes BUW, Schnürch M (2018) A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry. Chem Soc Rev 47:6603–6743PubMedPubMedCentralCrossRefGoogle Scholar
  31. 31.
    Rasheed OK, Sun B (2018) Advances in development of C–H activation/functionalization using a catalytic directing group. ChemistrySelect 3:5689–5708CrossRefGoogle Scholar
  32. 32.
    Okugawa N, Moriyama K, Togo H (2017) Introduction of quinolines and isoquinolines onto nonactivated α-C–H bond of tertiary amides through a radical pathway. J Org Chem 82:170–178PubMedCrossRefPubMedCentralGoogle Scholar
  33. 33.
    Li Z, Li C-J (2005) CuBr-catalyzed direct indolation of tetrahydroisoquinolines via cross-dehydrogenative coupling between sp3 C–H and sp2 C–H bonds. J Am Chem Soc 127:6968–6969PubMedCrossRefPubMedCentralGoogle Scholar
  34. 34.
    Ghobrial M, Harhammer K, Mihovilovic MD, Schnürch M (2009) Facile, solvent and ligand free iron catalyzed direct functionalization of N-protected tetrahydroisoquinolines and isochroman. Chem Commun 46:8836–8838CrossRefGoogle Scholar
  35. 35.
    Liu P, Zhou C-Y, Xiang S, Che C-M (2010) Highly efficient oxidative carbon–carbon coupling with SBA-15-support iron terpyridine catalyst. Chem Commun 46:2739–2741CrossRefGoogle Scholar
  36. 36.
    Ohta M, Quick MP, Yamaguchi J, Wünsch B, Itami K (2009) Fe-catalyzed oxidative coupling of heteroarenes and methylamines. Chem Asian J 4:1416–1419CrossRefGoogle Scholar
  37. 37.
    Shirakawa E, Yoneda T, Moriya K, Ota K, Uchiyama N, Nishikawa R, Hayashi T (2011) Iron-catalyzed oxidative coupling of alkylamines with arenes, nitroalkanes, and 1,3-dicarbonyl compounds. Chem Lett 40:1041–1043CrossRefGoogle Scholar
  38. 38.
    Marset X, Pérez JM, Ramón DJ (2016) Cross-dehydrogenative coupling reaction using copper oxide impregnated on magnetite in deep eutectic solvents. Green Chem 18:826–833CrossRefGoogle Scholar
  39. 39.
    Ho HE, Ishikawa Y, Asao N, Yamamoto Y, Jin T (2015) Highly efficient heterogeneous aerobic cross-dehydrogenative coupling via C–H functionalization of tertiary amines using a nanoporous gold skeleton catalyst. Chem Commun 51:12764–12767CrossRefGoogle Scholar
  40. 40.
    Liu Y, Wang C, Xue D, Xiao M, Li C, Xiao J (2017) Reactions catalysed by a binuclear copper complex: aerobic cross dehydrogenative coupling of N-aryl tetrahydroisoquinolines. Chem Eur J 23:3051–3061CrossRefGoogle Scholar
  41. 41.
    Su W, Yu J, Li Z, Jiang Z (2011) Solvent-free cross-dehydrogenative coupling reactions under high speed ball-milling conditions applied to the synthesis of functionalized tetrahydroisoquinolines. J Org Chem 76:9144–9150PubMedCrossRefPubMedCentralGoogle Scholar
  42. 42.
    Yang F, Li J, Xie J, Huang Z-Z (2010) Copper-catalyzed cross dehydrogenative coupling reactions of tertiary amines with ketones or indoles. Org Lett 12:5214–5217PubMedCrossRefPubMedCentralGoogle Scholar
  43. 43.
    Huang L, Niu T, Wu J, Zhang Y (2011) Copper-catalyzed oxidative cross-coupling of N,N-dimethylanilines with heteroarenes under molecular oxygen. J Org Chem 76:1759–1766PubMedCrossRefPubMedCentralGoogle Scholar
  44. 44.
    Romo-Pérez A, Miranda LD, García A (2015) Synthesis of N-methyl-5,6-dihydrobenzo[c]phenanthridine and its sp3 C(6)–H bond functionalization via oxidative cross-dehydrogenative coupling reactions. Tetrahedron Lett 56:6669–6673CrossRefGoogle Scholar
  45. 45.
    Dutta B, Sharma V, Sassu N, Dang Y, Weerakkody C, Macharia J, Miao R, Howell AR, Suib SL (2017) Cross dehydrogenative coupling of N-aryltetrahydroisoquinolines (sp3 C–H) with indoles (sp2 C–H) using a heterogeneous mesoporous manganese oxide catalyst. Green Chem 19:5350–5355CrossRefGoogle Scholar
  46. 46.
    Patil MR, Dedhia NP, Kapdi AR, Kumar AV (2018) Cobalt(II)/N-hydroxyphthalimide-catalyzed cross-dehydrogenative coupling reaction at room temperature under aerobic condition. J Org Chem 83:4477–4490PubMedCrossRefPubMedCentralGoogle Scholar
  47. 47.
    Wu C-J, Zhong J-J, Meng Q-Y, Lei T, Gao X-W, Tung C-H, Wu L-Z (2015) Cobalt-catalyzed cross-dehydrogenative coupling reaction in water by visible light. Org Lett 17:884–887PubMedCrossRefPubMedCentralGoogle Scholar
  48. 48.
    Tanoue A, Yoo W-J, Kobayashi S (2013) Antimony/N-hydroxyphthalimide as a catalyst system for cross-dehydrogenative coupling reactions under aerobic conditions. Adv Synth Catal 355:269–273Google Scholar
  49. 49.
    Alagiri K, Kumara GSR, Prabhu KR (2011) An oxidative cross-dehydrogenative-coupling reaction in water using molecular oxygen as the oxidant: vanadium catalyzed indolation of tetrahydroisoquinolines. Chem Commun 47:11787–11789CrossRefGoogle Scholar
  50. 50.
    Jones KM, Karier P, Klussmann M (2012) C1-substituted N-alkyl tetrahydroisoquinoline derivatives through V-catalyzed oxidative coupling. ChemCatChem 4:51–54CrossRefGoogle Scholar
  51. 51.
    Wang M-Z, Zhou C-Y, Wong M-K, Che C-M (2010) Ruthenium-catalyzed alkylation of indoles with tertiary amines by oxidation of a sp3 C–H bond and Lewis acid catalysis. Chem Eur J 16:5723–5735CrossRefGoogle Scholar
  52. 52.
    Dai C, Meschini F, Narayanam JMR, Stephenson CRJ (2012) Friedel-Crafts amidoalkylation via thermolysis and axidative photocatalysis. J Org Chem 77:4425–4431PubMedPubMedCentralCrossRefGoogle Scholar
  53. 53.
    Shelar DP, Li T-T, Chen Y, Fu W-F (2015) Platinum(II) Schiff base complexes as photocatalysts for visible-light-induced cross-dehydrogenative coupling reactions. ChemPlusChem 80:1541–1546CrossRefGoogle Scholar
  54. 54.
    Zhong J-J, Meng Q-Y, Wang G-X, Liu Q, Chen B, Feng K, Tung C-H, Wu L-Z (2013) A highly efficient and selective aerobic cross-dehydrogenative-coupling reaction photocatalyzed by a platinum(II) terpyridyl complex. Chem Eur J 19:6443–6450CrossRefGoogle Scholar
  55. 55.
    Chen W, Zheng H, Pan X, Xie Z, Zan X, Sun B, Liu L, Lou H (2014) A metal-free cross-dehydrogenative coupling of N-carbamoyl tetrahydroisoquinoline by sodium persulfate. Tetrahedron Lett 55:2879–2882CrossRefGoogle Scholar
  56. 56.
    Zhang Y, Teuscher KB, Ji H (2016) Direct α-heteroarylation of amides (α to nitrogen) and ethers through a benzaldehyde-mediated photoredox reaction. Chem Sci 7:2111–2118PubMedCrossRefPubMedCentralGoogle Scholar
  57. 57.
    Jones KM, Klussmann M (2012) Oxidative coupling of tertiary amines: scope, mechanism and challenges. Synlett 2012:159–162CrossRefGoogle Scholar
  58. 58.
    Ratnikov MO, Doyle MP (2013) Mechanistic investigation of oxidative Mannich reaction with tert-butyl hydroperoxide. The role of transition metal salt. J Am Chem Soc 135:1549–1557PubMedCrossRefPubMedCentralGoogle Scholar
  59. 59.
    Boess E, Sureshkumar D, Sud A, Wirtz C, Farès C, Klussmann M (2011) Mechanistic studies on a Cu-catalyzed aerobic oxidative coupling reaction with N-phenyl tetrahydroisoquinoline: structure of intermediates and the role of methanol as a solvent. J Am Chem Soc 133:8106–8109PubMedCrossRefPubMedCentralGoogle Scholar
  60. 60.
    Boess E, Schmitz C, Klussmann M (2012) A comparative mechanistic study of Cu-catalyzed oxidative coupling reactions with N-phenyltetrahydroisoquinoline. J Am Chem Soc 134:5317–5325PubMedCrossRefPubMedCentralGoogle Scholar
  61. 61.
    Scott M, Sud A, Boess E, Klussmann M (2014) Reaction progress kinetic analysis of a copper-catalyzed aerobic oxidative coupling reaction with N-phenyl tetrahydroisoquinoline. J Org Chem 79:12033–12040PubMedCrossRefPubMedCentralGoogle Scholar
  62. 62.
    Boess E, Wolf LM, Malakar S, Salamone M, Bietti M, Thiel W, Klussmann M (2016) Competitive hydrogen atom transfer to oxyl- and peroxyl radicals in the Cu-catalyzed oxidative coupling of N-aryl tetrahydroisoquinolines using tert-butyl hydroperoxide. ACS Catal 6:3253–3261CrossRefGoogle Scholar
  63. 63.
    Tsang AS-K, Jensen P, Hook JM, Hashmi ASK, Todd MH (2011) An oxidative carbon–carbon bond-forming reaction proceeds via an isolable iminium ion. Pure Appl Chem 83:655–665CrossRefGoogle Scholar
  64. 64.
    Cheng G-J, Song L-J, Yang Y-F, Zhang X, Wiest O, Wu Y-D (2013) Computational studies on the mechanism of the copper-catalyzed sp3-C–H cross-dehydrogenative coupling reaction. ChemPlusChem 78:943–951CrossRefGoogle Scholar
  65. 65.
    Schweitzer-Chaput B, Klussmann M (2013) Brønsted acid catalyzed C–H functionalization of N-protected tetrahydroisoquinolines via intermediate peroxides. Eur J Org Chem 2013:666–671CrossRefGoogle Scholar
  66. 66.
    Pu F, Li Y, Song Y-H, Xiao J, Liu Z-W, Wang C, Liu Z-T, Chen J-G, Lu J (2016) Copper-catalyzed coupling of indoles with dimethylformamide as a methylenating reagent. Adv Synth Catal 358:539–542CrossRefGoogle Scholar
  67. 67.
    Deb ML, Borpatra PJ, Saikia PJ, Baruah PK (2017) Introducing tetramethylurea as a new methylene precursor: a microwave-assisted RuCl3-catalyzed cross dehydrogenative coupling approach to bis(indolyl)methanes. Org Biomol Chem 15:1435–1443PubMedCrossRefPubMedCentralGoogle Scholar
  68. 68.
    Kaswan P, Nandwana NK, DeBoef B, Kumar A (2016) Vanadyl acetylacetonate catalyzed methylenation of imidazo[1,2-a]pyridines by using dimethylacetamide as a methylene source: direct access to bis(imidazo[1,2-a]pyridin-3-yl)methanes. Adv Synth Catal 358:2108–2115CrossRefGoogle Scholar
  69. 69.
    Yang J, Wang Z, Pan F, Li Y, Bao W (2010) CuBr-catalyzed selective oxidation of N-azomethine: highly efficient synthesis of methine-bridged bis-indole compounds. Org Biomol Chem 8:2975–2978PubMedCrossRefPubMedCentralGoogle Scholar
  70. 70.
    Li G, Nakamura H (2016) Synthesis of 2-indolyltetrahydroquinolines by zinc(II)-catalyzed intramolecular hydroarylation-redox cross-dehydrogenative coupling of N-propargylanilines with indoles. Angew Chem Int Ed 55:6758–6761CrossRefGoogle Scholar
  71. 71.
    Wang H, Dong M, Liu C, Zhang D (2018) Theoretical insight into the zinc(II)-catalyzed synthesis of 2-indolyltetrahydroquinolines from N-propargylanilines and indoles: cross-dehydrogenative coupling with temporally separated catalytic activity. Catal Sci Technol 8:1997–2007CrossRefGoogle Scholar
  72. 72.
    Meng Q-Y, Zhong J-J, Liu Q, Gao X-W, Zhang H-H, Lei T, Li Z-J, Feng K, Chen B, Tung C-H, Wu L-Z (2013) A cascade cross-coupling hydrogen evolution reaction by visible light catalysis. J Am Chem Soc 135:19052–19055PubMedCrossRefPubMedCentralGoogle Scholar
  73. 73.
    Segundo MS, Correa A (2018) Cross-dehydrogenative coupling reactions for the functionalization of α-amino acid derivatives and peptides. Synthesis 50:2853–2866CrossRefGoogle Scholar
  74. 74.
    Sonobe T, Oisaki K, Kanai M (2012) Catalytic aerobic production of imines en route to mild, green, and concise derivatizations of amines. Chem Sci 3:3249–3255CrossRefGoogle Scholar
  75. 75.
    Zhu Z-Q, Xiao L-J, Zhou C-C, Song H-L, Xie Z-B, Le Z-G (2018) A visible-light-promoted cross-dehydrogenative-coupling reaction of N-arylglycine esters with imidazo[1,2-a]pyridines. Tetrahedron Lett 59:3326–3331CrossRefGoogle Scholar
  76. 76.
    Zhu Z-Q, Xiao L-J, Chen Y, Xie Z-B, Zhu H-B, Le Z-G (2018) A highly efficient copper(II)-catalyzed cross-dehydrogenative-coupling reaction of N-arylglycine esters with 2-arylimidazo[1,2-a]pyridines. Synthesis 50:2775–2783CrossRefGoogle Scholar
  77. 77.
    Wu X, Zhang D, Zhou S, Gao F, Liu H (2015) Site-specific indolation of proline-based peptides via copper(II)-catalyzed oxidative coupling of tertiary amine N-oxides. Chem Commun 51:12571–12573CrossRefGoogle Scholar
  78. 78.
    Liu Z-Q, Li Z (2016) Radical-promoted site-specific cross dehydrogenative coupling of heterocycles with nitriles. Chem Commun 52:14278–14281CrossRefGoogle Scholar
  79. 79.
    Leskinen MV, Yip K-T, Valkonen A, Pihko PM (2012) Palladium-catalyzed dehydrogenative β′-functionalization of β-keto esters with indoles at room temperature. J Am Chem Soc 134:5750–5753PubMedCrossRefGoogle Scholar
  80. 80.
    Nimje RY, Leskinen MV, Pihko PM (2013) A three-component palladium-catalyzed oxidative C–C coupling reaction: a domino process in two dimensions. Angew Chem Int Ed 52:4818–4822CrossRefGoogle Scholar
  81. 81.
    Leskinen MV, Madarász Á, Yip K-T, Vuorinen A, Pápai I, Neuvonen AJ, Pihko PM (2014) Cross-dehydrogenative couplings between indoles and β-keto esters: ligand-assisted ligand tautomerization and dehydrogenation via a proton-assisted electron transfer to Pd(II). J Am Chem Soc 136:6453–6462PubMedCrossRefPubMedCentralGoogle Scholar
  82. 82.
    Zhu Y, Liu M, Jia F, Yuan J, Gao Q, Lian M, Wu A (2012) Metal-free sp3 C–H bond dual-(het)arylation: I2-promoted domino process to construct 2,2-bisindolyl-1-arylethanones. Org Lett 14:3392–3395PubMedCrossRefPubMedCentralGoogle Scholar
  83. 83.
    Mo H, Bao W (2009) Efficient palladium-catalyzed oxidative indolation of allylic compounds with DDQ via sp3 C–H bond activation and carbon-carbon bond formation under mild conditions. Adv Synth Catal 351:2845–2849CrossRefGoogle Scholar
  84. 84.
    Yu Y, Jiao L, Wang J, Wang H, Yu C, Hao E, Boens N (2017) Bu4NI/tBuOOH catalyzed, α-regioselective cross-dehydrogenative coupling of BODIPY with allylic alkenes and ethers. Chem Commun 53:581–584CrossRefGoogle Scholar

Copyright information

© Springer Nature Singapore Pte Ltd. 2019

Authors and Affiliations

  1. 1.Ural Federal UniversityEkaterinburgRussian Federation
  2. 2.I. Postovsky Institute of Organic SynthesisUral Branch of the Russian Academy of SciencesEkaterinburgRussian Federation

Personalised recommendations