Synlett 2014; 25(15): 2099-2110
DOI: 10.1055/s-0034-1378232
account
© Georg Thieme Verlag Stuttgart · New York

Synthetic Strategy for Multisubstituted Fused Furan Compounds Using Main-Group Metal Reagents

Hayato Tsuji*
a   Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan   Fax: +81(3)58414367   Email: tsuji@chem.s.u-tokyo.ac.jp   Email: nakamura@chem.s.u-tokyo.ac.jp
b   Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012, Japan   Fax: +81(3)58414367   Email: tsuji@chem.s.u-tokyo.ac.jp   Email: nakamura@chem.s.u-tokyo.ac.jp
,
Laurean Ilies
a   Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan   Fax: +81(3)58414367   Email: tsuji@chem.s.u-tokyo.ac.jp   Email: nakamura@chem.s.u-tokyo.ac.jp
,
Eiichi Nakamura*
a   Department of Chemistry, School of Science, The University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan   Fax: +81(3)58414367   Email: tsuji@chem.s.u-tokyo.ac.jp   Email: nakamura@chem.s.u-tokyo.ac.jp
› Author Affiliations
Further Information

Publication History

Received: 08 April 2014

Accepted after revision: 02 May 2014

Publication Date:
01 July 2014 (online)


Abstract

In this account, we summarize our recent studies on the synthesis of multisubstituted furan compounds. The synthetic strategy relies on the electrophilic cyclization of o-hydroxy(alkynyl)arenes by using main-group metal reagents. For example, zinc salts have been found to mediate the cyclization of o-alkynylphenols to form thermally stable yet chemically reactive β-zincio intermediates (‘synthetic modules’) that serve as platforms for the syntheses of a series of analogues having the same core structural motif (the ‘molecular library’). This modular approach is applicable to the synthesis of new benzofurans and benzodifurans and their homologues, and allows us to study the photophysical and semiconducting properties of these products systematically. We have similarly developed a synthesis of benzotrifurans by a cesium hydroxide-mediated tandem SNAr/triple-cyclization reaction, as well as a synthesis of trisubstituted furans by indium-catalyzed cyclo­isomerization of α-propargyl β-keto esters.

1 Introduction

2 Modular Approach for the Synthesis of Fused Furan Derivatives Using Zinc Salt

2.1 Zinc-Mediated Cyclization Reaction and Synthesis of Functionalized Benzofurans

2.2 Selective Syntheses of Benzodifurans Based on the Modular Method

2.3 Homologues of BDF: Naphtho- (NDF) and Anthradifurans (ADF)

3. Syntheses of Other Furans

3.1 Cesium Hydroxide-Promoted One-Pot Reaction for the Synthesis of Benzotrifurans

3.2 Indium-Catalyzed Cycloisomerization Reaction for the Synthesis of Multisubstituted Furans

4 Conclusions

 
  • References


    • For selected reviews on DOS, see:
    • 1a Schreiber SL. Science 2000; 287: 1964
    • 1b Arya P, Chou DT. H, Baek M.-G. Angew. Chem. Int. Ed. 2001; 40: 339
    • 1c Burke MD, Berger EM, Schreiber SL. Science 2003; 302: 613
    • 1d Tan DS. Nat. Chem. Biol. 2005; 1: 74
    • 1e Itami K, Yoshida J.-i. Bull. Chem. Soc. Jpn. 2006; 79: 811
    • 1f Itami K, Yoshida J.-i. Chem. Eur. J. 2006; 12: 3966
    • 1g Sunderhaus JD, Martin SF. Chem. Eur. J. 2009; 15: 1300

      For modular syntheses of polymers and coordination compounds, see:
    • 2a Yoshizawa M, Klosterman JK, Fujita M. Angew. Chem. Int. Ed. 2009; 48: 3418
    • 2b Lin W, Rieter WJ, Taylor KM. L. Angew. Chem. Int. Ed. 2009; 48: 650

      For modular syntheses of organic compounds, see:
    • 3a Tykwinski RR, Gholami M, Eisler S, Zhao Y, Melin F, Echegoyen L. Pure Appl. Chem. 2008; 80: 621
    • 3b Nakamura M. Pure Appl. Chem. 2006; 78: 425
    • 3c Tsuji H. Yuki Gosei Kagaku Kyokaishi 2010; 68: 1057
    • 3d Storer RI, Aciro C, Jones LH. Chem. Soc. Rev. 2011; 40: 2330

      For reactions of alkenes, see:
    • 4a Kubota K, Nakamura E. Angew. Chem. Int. Ed. Engl. 1997; 36: 2491
    • 4b Lorthiois E, Marek I, Normant JF. J. Org. Chem. 1998; 63: 566
    • 4c Rodriguez AL, Bunlaksananusorn T, Knochel P. Org. Lett. 2000; 2: 3285
    • 4d Pei T, Widenhoefer RA. J. Am. Chem. Soc. 2001; 123: 11290
    • 4e Yao X, Li C.-J. J. Am. Chem. Soc. 2004; 126: 6884
    • 4f Nakamura M, Hatakeyama T, Hara K, Nakamura E. J. Am. Chem. Soc. 2003; 125: 6362
    • 4g Nakamura M, Hatakeyama T, Nakamura E. J. Am. Chem. Soc. 2004; 126: 11820

      For intermolecular reactions of alkynes, see:
    • 5a Nakamura M, Liang C, Nakamura E. Org. Lett. 2004; 6: 2015
    • 5b Nakamura M, Fujimoto T, Endo K, Nakamura E. Org. Lett. 2004; 6: 4837
    • 5c Nakamura M, Endo K, Nakamura E. J. Am. Chem. Soc. 2003; 125: 13002
    • 5d Nakamura M, Endo K, Nakamura E. Org. Lett. 2005; 7: 3279
    • 5e Nakamura M, Endo K, Nakamura E. Adv. Synth. Catal. 2005; 347: 1681
    • 5f Endo K, Hatakeyama T, Nakamura M, Nakamura E. J. Am. Chem. Soc. 2007; 129: 5264
    • 5g Tsuji H, Fujimoto T, Endo K, Nakamura M, Nakamura E. Org. Lett. 2008; 10: 1219
    • 5h Fujimoto T, Endo K, Tsuji H, Nakamura M, Nakamura E. J. Am. Chem. Soc. 2008; 130: 4492
    • 5i Tsuji H, Yamagata K.-i, Fujimoto T, Nakamura E. J. Am. Chem. Soc. 2008; 130: 7792
    • 5j Yoshikai N, Zhang S.-L, Yamagata K.-i, Tsuji H, Nakamura E. J. Am. Chem. Soc. 2009; 131: 4099
    • 5k Tsuji H, Tanaka I, Endo K, Yamagata K, Nakamura M, Nakamura E. Org. Lett. 2009; 11: 1845

      For intramolecular reactions of alkynes, see:
    • 6a Tsuji H, Yamagata K.-i, Itoh Y, Endo K, Nakamura M, Nakamura E. Angew. Chem. Int. Ed. 2007; 46: 8060
    • 6b Itoh Y, Tsuji H, Yamagata K.-i, Endo K, Tanaka I, Nakamura M, Nakamura E. J. Am. Chem. Soc. 2008; 130: 17161

      For reviews on transition metal-catalyzed benzofuran synthesis, see:
    • 7a Cacchi S, Fabrizi G, Goggiamani A. Org. Biomol. Chem. 2011; 9: 641
    • 7b Zeni G, Larock RC. Chem. Rev. 2006; 106: 4644

      For recent examples of transition metal-catalyzed benzofuran syntheses, see:
    • 8a Chen C.-Y, Dormer PG. J. Org. Chem. 2005; 70: 6964
    • 8b Nakamura I, Mizushima Y, Yamamoto Y. J. Am. Chem. Soc. 2005; 127: 15022
    • 8c Carril M, SanMartin R, Tellitu I, Domínguez E. Org. Lett. 2006; 8: 1467
    • 8d Lu B, Wang B, Zhang Y, Ma D. J. Org. Chem. 2007; 72: 5337
    • 8e Anderson KW, Ikawa T, Tundel RE, Buchwald SL. J. Am. Chem. Soc. 2006; 128: 10694
    • 8f Tsuchikama K, Hashimoto Y, Endo K, Shibata T. Adv. Synth. Catal. 2009; 351: 2850
    • 8g Majumdar KC, Chattopadhyay B, Chakravorty S. Synthesis 2009; 674
    • 8h Wang J.-R, Manabe K. J. Org. Chem. 2010; 75: 5340
    • 8i Maimone TJ, Buchwald SL. J. Am. Chem. Soc. 2010; 132: 9990
    • 8j Hirano K, Satoh T, Miura M. Org. Lett. 2011; 13: 2395
    • 8k Hachiya H, Hirano K, Satoh T, Miura M. Org. Lett. 2011; 13: 3076
    • 8l Shibata T, Hashimoto Y.-k, Otsuka M, Tsuchikama K, Endo K. Synlett 2011; 2075
    • 8m Wang S, Li P, Yu L, Wang L. Org. Lett. 2011; 13: 5968
    • 8n Matsuda N, Hirano K, Satoh T, Miura M. J. Org. Chem. 2012; 77: 617
    • 8o Kuram MR, Bhanuchandra M, Sahoo AK. Angew. Chem. Int. Ed. 2013; 52: 4607
    • 8p Shigeta M, Watanabe J, Konishi G. Tetrahedron Lett. 2013; 54: 1761

      For recent examples of other methods, see:
    • 9a Kumar MP, Liu R.-S. J. Org. Chem. 2006; 71: 4951
    • 9b Takeda N, Miyata O, Naito T. Eur. J. Org. Chem. 2007; 1491
    • 9c Kobatake T, Fujino D, Yoshida S, Yorimitsu H, Oshima K. J. Am. Chem. Soc. 2010; 132: 11838
    • 9d Pei T, Chen C.-y, DiMichele L, Davies IW. Org. Lett. 2010; 12: 4972
    • 9e Schevenels F, Markó IE. Org. Lett. 2012; 14: 1298
    • 9f Singh FV, Wirth T. Synthesis 2012; 44: 1171

      For recent examples of multiple-cyclization reactions, see:
    • 10a Yue D, Yao T, Larock RC. J. Org. Chem. 2005; 70: 10292
    • 10b Liang Z, Ma S, Yu J, Xu R. J. Org. Chem. 2007; 72: 9219
    • 10c Liang Z, Ma S, Yub J, Xu R. Tetrahedron 2007; 63: 12877
    • 10d Matsuura Y, Tanaka Y, Akita M. J. Organomet. Chem. 2009; 694: 1840
    • 10e Gay RM, Manarin F, Schneider CC, Barancelli DA, Costa MD, Zeni G. J. Org. Chem. 2010; 75: 5701
    • 10f Yi C, Blum C, Lehmann M, Keller S, Liu S.-X, Frei G, Neels A, Hauser J, Schürch S, Decurtins S. J. Org. Chem. 2010; 75: 3350
    • 10g Kundu D, Samim M, Majee A, Hajra A. Chem. Asian J. 2011; 6: 406
    • 10h Moussallem C, Gohier F, Mallet C, Allain M, Frère P. Tetrahedron 2012; 68: 8617
    • 11a Brown RC. D. Angew. Chem. Int. Ed. 2005; 44: 850
    • 11b Bunz UH. F. Angew. Chem. Int. Ed. 2010; 49: 5037
    • 11c Heterocycles in Natural Product Synthesis . Majumdar KC, Chattopadhyay SK. Wiley; Chichester: 2011
    • 11d Handbook of Heterocyclic Chemistry. Katritzky AR, Ramsden CA, Joule JA, Zhdankin VV. Elsevier; Amsterdam: 2010. 3rd ed.
    • 11e Simonetti SO, Larghi EL, Bracca AB. J, Kaufman TS. Nat. Prod. Rep. 2013; 30: 941

      For examples, see:
    • 12a Heltzel CE, Gunatilaka AA. L, Glass TE, Kingston DG. I. Tetrahedron 1993; 49: 6757
    • 12b Chambers JJ, Kurrasch-Orbaugh DM, Parker MA, Nichols DE. J. Med. Chem. 2001; 44: 1003
  • 14 For an example of postfunctionalization of fused furan compounds, see: Li Y, Waser J. Beilstein J. Org. Chem. 2013; 9: 1763
    • 15a Nakamura M, Ilies L, Otsubo S, Nakamura E. Angew. Chem. Int. Ed. 2006; 45: 944
    • 15b Nakamura M, Ilies L, Otsubo S, Nakamura E. Org. Lett. 2006; 8: 2803
  • 16 Kraemer G, Spilker A. Ber. Dtsch. Chem. Ges 1890; 23: 78
  • 17 Stoermer J. Ber. Dtsch. Chem. Ges. 1897; 30: 1700
  • 18 Knochel P, Singer RD. Chem. Rev. 1993; 93: 2117 ; and references therein
  • 19 Nakamura E, Aoki S, Sekiya K, Oshino H, Kuwajima I. J. Am. Chem. Soc. 1987; 109: 8056
  • 20 Yoshikai N, Miura K, Nakamura E. Adv. Synth. Catal. 2009; 351: 1014
  • 21 Yoshikai N, Zhang S.-L, Nakamura E. J. Am. Chem. Soc. 2009; 130: 12862
  • 22 Matsuzawa S, Horiguchi Y, Nakamura E, Kuwajima I. Tetrahedron 1989; 45: 349
    • 23a Tsuji H, Mitsui C, Ilies L, Sato Y, Nakamura E. J. Am. Chem. Soc. 2007; 129: 11902
    • 23b Tsuji H, Mitsui C, Sato Y, Nakamura E. Adv. Mater. (Weinheim, Ger.) 2009; 21: 3776

      For early studies on the semiconducting properties of furans and their applications, see:
    • 24a Zhang L.-Z, Chen C.-W, Lee C.-C, Luh T.-Y. Chem. Commun. 2002; 2336
    • 24b Wu C.-C, Hung W.-Y, Liu T.-L, Zhang L.-Z, Luh T.-Y. J. Appl. Phys. 2003; 93: 5465
    • 24c Anderson S, Taylor PN, Verschoor GL. B. Chem. Eur. J. 2004; 10: 518
    • 24d Miyata Y, Nishinaga T, Komatsu K. J. Org. Chem. 2005; 70: 1147
    • 24e Miyata Y, Terayama M, Minari T, Nishinaga T, Nemoto T, Isoda S, Komatsu K. Chem. Asian J. 2007; 2: 1492

      For studies on photophysical properties and structures of fused furans, see:
    • 25a Abdul-Aziz M, Auping JV, Meador MA. J. Org. Chem. 1995; 60: 1303
    • 25b Takahashi K, Kobayashi K. J. Org. Chem. 2000; 65: 2577
    • 25c Kang SK, Park KK, Kim WC, Kim S.-H. Acta Crystallogr., Sect. E 2004; 60: o1195
    • 25d Gu JM, Hu X.-R, Xu W.-M. Acta Crystallogr., Sect. E 2005; 61: o3674
  • 26 Handbook of Thiophene-Based Materials: Applications in Organic Electronics and Photonics. Perepichka IF, Perepichka DF. Wiley; Chichester: 2009
    • 27a Japp FR, Meldrum AN. J. Chem. Soc., Trans. 1899; 75: 1035

    • The reaction was later proved to afford a sizable amount of regioisomeric 1,2,7,8-tetraarylbenzo[1,2-b:4,3-b']difuran as a byproduct; see:
    • 27b le Fèvre RJ. W, Taylor CR, Whittem RN. J. Chem. Soc. 1948; 1992
    • 27c Dischendorfer O, Limontschew W. Monatsh. Chem. 1949; 80: 58
    • 27d Domschke G. Chem. Ber. 1966; 99: 930
  • 28 Cacchi S, Fabrizi G, Goggiomani A. Heterocycles 2002; 56: 613
  • 29 Note that cyclization itself takes place without prior deprotonation with butyllithium to afford the p-BDF 4; however, it results in a lower yield.
    • 30a Negishi E, King AO, Okukado N. J. Org. Chem. 1977; 42: 1821
    • 30b Negishi E, Takahashi T, King AO. Org. Synth. 1985; 66: 67
    • 30c Negishi E. Angew. Chem. Int. Ed. 2011; 50: 6738
  • 31 Yamamoto T, Nishiyama M, Koie Y. Tetrahedron Lett. 1998; 39: 2367
  • 32 Fu GC. Acc. Chem. Res. 2008; 41: 1555
  • 33 Dai C, Fu GC. J. Am. Chem. Soc. 2001; 123: 2719
    • 34a Tsuji H, Favier GM. O, Mitsui C, Lee S, Hashizume D, Nakamura E. Chem. Lett. 2011; 40: 576
    • 34b Mitsui C, Tanaka H, Tsuji H, Nakamura E. Chem. Asian J. 2011; 6: 2296
    • 34c Mitsui C, Tsuji H, Sato Y, Nakamura E. Chem. Asian J. 2012; 7: 1443
  • 35 Tsuji H, Mitsui C, Sato Y, Nakamura E. Heteroat. Chem. 2011; 22: 316
    • 36a Mitsui C, Soeda J, Miwa K, Tsuji H, Takeya J, Nakamura E. J. Am. Chem. Soc. 2012; 134: 5448
    • 36b Tsuji H, Shoyama K, Nakamura E. Chem. Lett. 2012; 41: 957
  • 37 Mitsui, C.; Tsuji, H.; Nakamura, E. unpublished results.

    • For examples of solution-processable organic materials, see:
    • 38a Minemawari H, Yamada T, Matsui H, Tsutsumi J, Haas S, Chiba R, Kumai R, Hasegawa T. Nature 2011; 475: 364
    • 38b Okamoto T, Mitsui C, Yamagishi M, Nakahara K, Soeda J, Hirose Y, Miwa K, Sato H, Yamano A, Matsushita T, Uemura T, Takeya J. Adv. Mater. (Weinheim, Ger.) 2013; 25: 6392
  • 39 Tsuji H, Cantagrel G, Ueda Y, Chen T, Wan L.-J, Nakamura E. Chem. Asian J. 2013; 8: 2377
    • 40a Brown BR, Somerfield GA, Weitzman PD. J. J. Chem. Soc. 1958; 4305
    • 40b Li Y, Lampkins AJ, Baker MB, Sumpter BG, Huang J, Abboud KA, Castellano RK. Org. Lett. 2009; 11: 4314
  • 41 Tsuji H, Yamagata K.-i, Ueda Y, Nakamura E. Synlett 2011; 1015
  • 42 Frost CG, Hartley JP, Griffin D. Tetrahedron Lett. 2002; 43: 4789

    • For nitrogen-containing heterocyclic compounds, see:
    • 43a Tsuji H, Yokoi Y, Mitsui C, Ilies L, Sato Y, Nakamura E. Chem. Asian J. 2009; 4: 655
    • 43b Tsuji H, Yokoi Y, Sato Y, Tanaka H, Nakamura E. Chem. Asian J. 2011; 6: 2005
    • 43c Tsuji H, Yokoi Y, Furukawa S, Nakamura E. Heterocycles 2014; in press; doi:10.3987/COM-14-S(K)16

      For modular approaches to the synthesis of phosphorus-containing heterocyclic compounds, see:
    • 44a Tsuji H, Sato K, Ilies L, Itoh Y, Sato Y, Nakamura E. Org. Lett. 2008; 10: 2263
    • 44b Tsuji H, Sato K, Sato Y, Nakamura E. J. Mater. Chem. 2009; 19: 3364
    • 44c Tsuji H, Sato K, Sato Y, Nakamura E. Chem. Asian J. 2010; 5: 1294
    • 44d Kojima T, Furukawa S, Tsuji H, Nakamura E. Chem. Lett. 2014; 43: 676

      For silicon-containing heterocyclic compounds, see:
    • 45a Ilies L, Tsuji H, Sato Y, Nakamura E. J. Am. Chem. Soc. 2008; 130: 4240
    • 45b Ilies L, Tsuji H, Nakamura E. Org. Lett. 2009; 11: 3966
    • 45c Ilies L, Sato Y, Mitsui C, Tsuji H, Nakamura E. Chem. Asian J. 2010; 5: 1376

      For polysubstituted hydrocarbons, see:
    • 46a Tsuji H, Ueda Y, Ilies L, Nakamura E. J. Am. Chem. Soc. 2010; 132: 11854
    • 46b Ueda Y, Tsuji H, Tanaka H, Nakamura E. Chem. Asian J. 2014; 9: 1623 ; see also refs. 5 (i) and 5 (j)

      For carbocyclic compounds, see:
    • 47a Zhu X, Mitsui C, Tsuji H, Nakamura E. J. Am. Chem. Soc. 2009; 131: 13596
    • 47b Zhu X, Tsuji H, Nakabayashi K, Ohkoshi S.-i, Nakamura E. J. Am. Chem. Soc. 2011; 133: 16342
    • 47c Zhu X, Tsuji H, López-Navarrete JT, Casado J, Nakamura E. J. Am. Chem. Soc. 2012; 134: 19254
    • 47d Zhu X, Tsuji H, Yella A, Chauvin A.-S, Grätzel M, Nakamura E. Chem. Commun. 2013; 49: 582
    • 47e Tsuji H, Ota Y, Furukawa S, Mitsui C, Sato Y, Nakamura E. Asian J. Org. Chem. 2012; 1: 34
    • 47f Sukegawa J, Tsuji H, Nakamura E. Chem. Lett. 2014; 43: 699
  • 48 Organic Field-Effect Transistors . Bao Z, Locklin J. CRC Press; Boca Raton: 2007
    • 49a Organic Light-Emitting Devices: Synthesis, Properties and Applications. Müllen K, Scherf U. Wiley-VCH; Weinheim: 2006
    • 49b Organic Light-Emitting Devices: A Survey . Shinar J. Springer; New York: 2004
    • 49c Li Z, Meng H. Organic Light-Emitting Materials and Devices . CRC Press; Boca Raton: 2007

      For furan-containing functional materials, see:
    • 50a Shukla R, Wadumethrige SH, Lindeman SV, Rathore R. Org. Lett. 2008; 10: 3587
    • 50b Hayashi N, Saito Y, Higuchi H, Suzuki K. J. Phys. Chem. A 2009; 113: 5342
    • 50c Caruso U, Panunzi B, Roviello GN, Roviello G, Tingoli M, Tuzi A. C. R. Chim. 2009; 12: 622
    • 50d Li H, Jiang P, Yi C, Li C, Liu S.-X, Tan S, Zhao B, Braun J, Meier W, Wandlowski T, Decurtins S. Macromolecules 2010; 43: 8058
    • 50e Santos-Pérez J, Crespo-Hernández CE, Reichardt C, Cabrera CR, Feliciano-Ramos I, Arroyo-Ramírez L, Meador MA. J. Phys. Chem. A 2011; 115: 4157
    • 50f Xiao J, Yang B, Wong JI, Liu Y, Wei F, Tan KJ, Teng X, Wu Y, Huang L, Kloc C, Boey F, Ma J, Zhang H, Yang HY, Zhang Q. Org. Lett. 2011; 13: 3004
    • 50g Bijleveld JC, Karsten BP, Mathijssen SG. J, Wienk MM, de Leeuw DM, Janssen RA. J. J. Mater. Chem. 2011; 21: 1600
    • 50h Niimi K, Mori H, Miyazaki E, Osaka I, Kakizoe H, Takimiya K, Adachi C. Chem. Commun. 2012; 48: 5892
    • 50i Kobilka BM, Dubrovskiy AV, Ewan MD, Tomlinson AL, Larock RC, Chaudhary S, Jeffries-El M. Chem. Commun. 2012; 48: 8919
    • 50j Li H, Tang P, Zhao Y, Liu S.-X, Aeschi Y, Deng L, Braun J, Zhao B, Liu Y, Tan S, Meier W, Decurtins S. J. Polym. Sci., Part A: Polym. Chem. 2012; 50: 2935
    • 50k Mitsui C, Okamoto T, Matsui H, Yamagishi M, Matsushita T, Soeda J, Miwa K, Sato H, Yamano A, Uemura T, Takeya J. Chem. Mater. 2013; 25: 3952
    • 50l Nakahara K, Mitsui C, Okamoto T, Yamagishi M, Miwa K, Sato H, Yamano A, Uemura T, Takeya J. Chem. Lett. 2013; 42: 654
    • 50m Li H, Ding J, Chen S, Beyer C, Liu S.-X, Wagenknecht H.-A, Hauser A, Decurtins S. Chem. Eur. J. 2013; 19: 6459
    • 50n Li S, Yuan J, Deng P, Ma W, Zhang Q. Sol. Energy Mater. Sol. Cells 2013; 118: 22
    • 50o Bosiak MJ, Rakowiecki M, Orlowska KJ, Kedziera D, Adams J. Dyes Pigm. 2013; 99: 803
    • 50p Gidron O, Dadvand A, Sun EW.-H, Chung I, Shimon LJ. W, Bendikov M, Perepichka DF. J. Mater. Chem. C 2013; 1: 4358
    • 50q Mallet C, Didane Y, Watanabe T, Yoshimoto N, Allain M, Videlot-Ackermann C, Frère P. ChemPlusChem 2013; 78: 459
    • 50r Shi S, Xie X, Gao C, Shi K, Chen S, Yu G, Guo L, Li X, Wang H. Macromolecules 2014; 47: 616
    • 50s Moussalem C, Segut O, Gohier F, Allain M, Frére P. ACS Sustainable Chem. Eng. 2014; 2: 1043
    • 50t Huang W, Yang B, Sun J, Liu B, Yang J, Zou Y, Xiong J, Zhou C, Gao Y. Org. Electron. 2014; 15: 1050
    • 50u Nakahara K, Mitsui C, Okamoto T, Yamagishi M, Matsui H, Ueno T, Tanaka Y, Yano M, Matsushita T, Soeda J, Hirose Y, Sato H, Yamano A, Takeya J. Chem. Commun. 2014; 50: 5342 ; see also Ref. 10 (i)

      For recent examples of heterocyclic compounds including oxygen and other heteroatoms, see:
    • 51a Washington MP, Gudimetla VB, Laughlin FL, Deligonul N, He S, Payton JL, Simpson MC, Protasiewicz JD. J. Am. Chem. Soc. 2010; 132: 4566
    • 51b Chen H, Delaunay W, Li J, Wang Z, Bouit P.-A, Tondelier D, Geffroy B, Mathey F, Duan Z, Réau R, Hissler M. Org. Lett. 2013; 15: 330
    • 51c Aeschi Y, Li H, Cao Z, Chen S, Amacher A, Bieri N, Özen B, Hauser J, Decurtins S, Tan S, Liu S.-X. Org. Lett. 2013; 15: 5586

      For recent examples of furan compounds, see:
    • 52a Chou C.-M, Chen C.-H, Lin C.-L, Yang K.-W, Lim T.-S, Luh T.-Y. Tetrahedron 2009; 65: 9749
    • 52b Woo CH, Beaujuge PM, Holcombe TW, Lee OP, Fréchet JM. J. J. Am. Chem. Soc. 2010; 132: 15547
    • 52c Gidron O, Diskin-Posner Y, Bendikov M. J. Am. Chem. Soc. 2010; 132: 2148
    • 52d Mohakud S, Woo CH, Alex AP, Pati SK. J. Phys. Chem. C 2010; 114: 20436
    • 52e Gidron O, Dadvand A, Sheynin Y, Bendikov M, Perepichka DF. Chem. Commun. 2011; 47: 1976
    • 52f Yuan J, Huang X, Zhang F, Lu J, Zhai Z, Di C, Jiang Z, Ma W. J. Mater. Chem. 2012; 22: 22734
    • 52g Mitsudo K, Harada J, Tanaka Y, Mandai H, Nishioka C, Tanaka H, Wakamiya A, Murata Y, Suga S. J. Org. Chem. 2013; 78: 2763
    • 52h Ledwon P, Lapkowski M, Licha T, Frydel J, Idzik KR. Synth. Met. 2014; 191: 74
    • 52i Nakanishi K, Sasamori T, Kuramochi K, Tokitoh N, Kawabata T, Tsubaki K. J. Org. Chem. 2014; 79: 2625