- 1Institut de Chimie Organique et Analytique, Université d'Orléans, UMR CNRS 7311, Orléans, France
- 2Institut de Chimie Moléculaire et des Matériaux d'Orsay, Université Paris Sud, Université Paris Saclay, UMR CNRS 8182, Orsay, France
General and efficient approaches for the synthesis of new 5-amino and 5-iminoimidazo[1,2-a]imidazoles were developed through a three-component reaction of 1-unsubstituted 2-aminoimidazoles with various aldehydes and isocyanides mediated by zirconium(IV) chloride. The protocols were established considering the reactivity of the starting substrate, which varies depending on the presence of a substituent on the 2-aminoimidazole moiety. A library of new N-fused ring systems with wide structural diversification, novel synthetic, and potential pharmacological interest was obtained in moderate to good yields.
Introduction
The development of innovative synthetic approaches that allow rapid access to a wide variety of new heterocyclic derivatives is of crucial interest. The use of multicomponent reactions (MCRs) offers significant advantages in organic synthesis, such as the combination of chemical transformations of three or more different starting materials in a one-pot procedure without isolating the intermediates (Dömling and Ugi, 2000; Dömling, 2006; Abdelraheem et al., 2017; Bariwal et al., 2018; Murlykina et al., 2018). In 1998, the groups of Groebke, Blackburn, and Bienayme simultaneously developed a new subclass of MCRs to produce a series of azine- and azole-fused aminoimidazoles, using diverse 2-aminoazines or 2-aminoazoles, aldehydes and isocyanides in the presence of Lewis or Brønsted acid catalysts (Bienayme and Bouzid, 1998; Blackburn, 1998; Groebke et al., 1998).
This reaction recently attracted much attention in organic and medicinal chemistry because of its simplicity, efficiency and the ability to generate diverse compound libraries (Devi et al., 2015; Kaur et al., 2016; Shaaban and Abdel-Wahab, 2016; Shaabani and Hooshmand, 2016).
The fused bicyclic 5-5 systems containing three nitrogen atoms with one in the bridgehead position are an important class of fused heterocyclic compounds in organic and medicinal chemistry due to their relevant biological properties, such as anti-cancer (Baviskar et al., 2011; Grosse et al., 2014; Sidduri et al., 2014; Meta et al., 2017), anti-viral (Elleder et al., 2012), anti-inflammatory (Bruno et al., 2007; Brullo et al., 2012), and anti-diabetic effects (Mascitti et al.). Our group has been involved over the last few years in the development of powerful tools for the synthesis of such systems (El Akkaoui et al., 2012; Grosse et al., 2012, 2013, 2014; Arnould et al., 2013; Tber et al., 2015a,b; Driowya et al., 2018). For instance, we very recently reported an efficient one-pot three component procedure for the synthesis of new functionalized imidazo[1,2-b]pyrazole derivatives in addition to a library of hitherto undescribed 7,7′-(substituted methylene)bis-imidazo[1,2-b]pyrazoles starting from 3-aminopyrazoles, various aldehydes and isocyanides, using a catalytic amount of perchloric acid or zirconium(IV) chloride (Driowya et al., 2018).
The imidazo-imidazole scaffolds hold a special place in this category, since they are found in compounds showing a wide range of pharmaceutical activities. In particular, they have been described as antifungal (Lila et al., 2003), antithrombotic (Imaeda et al., 2008; Fujimoto et al., 2009), anxiolytic and anti-depressive agents (Han et al., 2005; Tellew and Luo, 2008; Zuev et al., 2010). In addition, they have been reported as androgen receptor agonists and antagonists that are useful in the treatment of a variety of disorders (Zhang et al., 2006). Several synthetic methods based on multistep synthesis have been employed by our group and others to prepare these medicinally important N-fused imidazoles (Langer et al., 2001; Poje and Poje, 2003; Adib et al., 2008; Saima et al., 2012; Chen et al., 2013; Grosse et al., 2015; Castanedo et al., 2016; Loubidi et al., 2016; Kheder and Farghaly, 2017).
On the other hand, compounds containing an imidazo[1,2-a]imidazole moiety have been understudied (Compernolle and Toppet, 1986; Kolar and Tisler, 1995; Mas et al., 2002). Only one paper was found in the literature for the preparation of 5-aminoimidazo[1,2-a]imidazole compounds by MCRs starting from 1,5-disubstituted 2-aminoimidazoles (Pereshivko et al., 2013). However, the reported protocol gave poor to moderate yields and showed some limitations with 1-unsubstituted 2-aminoimidazole substrates. Hence, there is a need to develop a new, more efficient and general method for the preparation of these derivatives.
In this context, and in continuation of our ongoing search for innovative small molecules, we report herein novel and straightforward approaches for the synthesis of new series of 5-amino and 5-iminoimidazo[1,2-a]imidazoles starting from 1-unsubstituted 2-aminoimidazoles and using zirconium(IV) chloride as catalyst. To the best of our knowledge, this is the first report using 1-unsubstituted 2-aminoimidazoles in MCRs.
Results And Discussion
In order to find a MCR protocol that can afford an efficient formation of 5-aminoimidazo[1,2-a]imidazoles, we initially performed a model reaction using ethyl 2-aminoimidazole-4-carboxylate 1 with benzaldehyde and t-octyl isocyanide under different conditions (Table 1). Two possible regioisomers can be formed in this case 4a or 4a′ according on which side of the 2-aminoimidazole 1 that reacts.
In our last study, we showed that the Lewis acid zirconium(IV) chloride delivered an efficient catalytic effect for the MCR (Driowya et al., 2018). This catalyst was therefore chosen for the present optimization study.
First, the reaction was carried out in methanol at room temperature in presence of 5 mol% of ZrCl4, but unfortunately, no product was observed (entry 1). Poor yields of the expected product 4a or 4a′ were obtained when the reaction was performed under heating in ethanol with either 5 or 10 mol% of ZrCl4 (entries 2 and 3). The reaction time was significantly reduced to 10 min under MW irradiation at 140°C, and the yield was relatively improved to 38% (entry 4). The use of n-BuOH as solvent instead of EtOH under MW irradiation resulted in an improvement of the yield to 62% (entry 5), whereas the use of PEG-400 gave a moderate yield (entry 6). Interestingly, the reaction in PEG-400 under classical heating at 75°C during 4 h provided a very good yield (entry 7). Moreover, the optimal amount of catalyst (10 mol%) was confirmed, since the use of 5 mol% resulted in a lower yield (entry 8). Finally, replacing ZrCl4 by other catalysts such as p-TsOH or ZnCl2 was associated with a significant decrease in the yield of the product 5-aminoimidazo[1,2-a]imidazole 4a or 4a′ (entries 9 and 10).
Hence, the optimized reaction conditions were found to be ZrCl4 (10 mol%) as catalyst and PEG-400 as solvent with heating at 75°C during 4 h. This system was used before for the preparation of imidazo[1,2-a]pyridines (Guchhait and Madaan, 2009).
In order to disclose the structure of the formed regioisomer of this reaction, we carried out a single-crystal X-ray analysis of the product (Figure 1). The results reveal the formation of the regioisomer 4a. The regioselectivity of this reaction can be explained by the presence of intermolecular hydrogen bonds on the ethyl 2-aminoimidazole-4-carboxylate 1, orienting the synthesis toward the formation of only the regioisomer 4a. Moreover, the structure of compound 4a is stabilized by intramolecular N-H…O and intermolecular N-H…N interactions as observed in the crystalline structure (see the crystallographic section on the Supplementary Material).
With these reaction conditions in hand, we next explored the scope and limitation of our methodology with diverse 2-aminoimidazoles and isocyanides in the presence of a range of aldehydes as shown in Table 2. A large chemical library of 5-aminoimidazo[1,2-a]imidazole derivatives 4a–f and 5a–i was designed in generally good yields. The reactions proceeded well with both ethyl 2-aminoimidazole-4-carboxylate 1 and 4,5-dicyano-2-aminoimidazole 2. Unfortunately, no reaction was observed when employing the unsubstituted 2-aminoimidazole 3 as substrate, which was recovered after purification.
Moreover, the reaction occurred with electron-withdrawing and electron-donating substituents of the benzaldehydes, in addition to sterically hindered aldehydes (entry 9), aliphatic and heteroaromatic aldehydes (entries 12 and 13, respectively). However, a poor yield was obtained when using propionaldehyde (entry 12).
The impact of isocyanide on our reaction was also investigated; the tert-octyl isocyanide and tert-butyl isocyanide gave similar good results, whereas the cyclohexyl isocyanide showed slightly lower yields.
The MCR involving the unsubstituted 2-aminoimidazole 3 using our conditions did not yield any product. This can be explained by the poor reactivity of the starting substrate due to the absence of an electron-withdrawing group.
In order to find another strategy allowing us to synthetize 5-aminoimidazo[1,2-a]imidazoles starting from the unsubstituted 2-aminoimidazole 3, we first carried out the condensation of the latter with p-anisaldehyde as a first step model reaction under different conditions (Table 3). The free amine 3 was prepared from the commercially available 2-aminoimidazole sulfate (see Supplementary Material). Initially, conventional or MW heating of the reaction in different solvents with ZrCl4 (10 mol%) as catalyst provided the desired imine 6a in poor yields (entries 1–4). The use of ZnCl2 as catalyst furnished a very low yield (entry 5), while p-TsOH and InCl3 gave slightly higher yields (entries 6 and 7). Very interestingly, using a reduced catalytic amount of InCl3 (2 mol% instead of 10 mol%) under conventional or MW heating in ethanol produced a real improvement in terms of yield and reaction time (entries 9 and 11). This may explain the non-reactivity observed in the MCR (Table 2, entry 16), because of the instability of the formed imine under such acidic conditions. However, the prolonged reaction time noted with ZrCl4 (2 mol%) or when no catalyst was used, revealed the influence of InCl3 on this condensation reaction (entries 8 and 10, respectively).
After developing these optimized conditions for the first reaction step, we next focused on finding the best conditions for the second step, which is based on the [4+1] cycloaddition reaction of the formed imine with an isocyanide.
The resulting imine 6a was isolated and reacted with tert-octyl isocyanide under several catalytic conditions (Table 4). No reaction occurred when using the same conditions as for the condensation step (entry 1). Increasing the catalytic amount of InCl3 to 10 mol% produced the desired product in poor yields with either conventional or MW heating methods (entries 2 and 3). It is interesting to note that the 5-aminoimidazo[1,2-a]imidazole product formed was unstable and underwent a dehydrogenation reaction in situ to generate the corresponding stable oxidized compound 5-iminoimidazo[1,2-a]imidazole 7a. We already observed this type of oxidation in our previous work on the synthesis of imidazo[1,2-b]pyrazoles by MCRs (Driowya et al., 2018).
The use of other catalysts such as p-TsOH, ZnCl2, and ZrCl4 under microwave irradiation did not produce any significant improvement in the reaction yield (entries 4–6). However, using ZrCl4 as catalyst and replacing EtOH by n-BuOH as solvent for the reaction showed a slight increase in the yield to 40% (entry 8), which was the optimum result obtained for this reaction. The same conditions used under conventional heating resulted in a significant decrease in the yield. The low yield and the difficulty of this reaction can be explained by the instability of the imine in the acid medium.
With these optimized conditions in hand, we succeeded in achieving the one-pot two-step procedure without isolating the imine by removing EtOH at the end of the first reaction step. The isolated product 7a was obtained with a global yield of 32%. This protocol was next extended to the synthesis of series of 5-iminoimidazo[1,2-a]imidazoles 7a–i starting from the unsubstituted 2-aminoimidazole and exploring a wide range of aldehydes and isocyanides (Table 5). As mentioned previously, the 5-aminoimidazo[1,2-a]imidazole products formed were unstable and led directly to the corresponding imine forms 7a–i. Despite the low yields obtained, it was nevertheless possible to produce the targeted compounds, which proved unsuccessful with the methods developed previously or with those cited in the literature.
The chemical space of our synthetized compounds was then enlarged, by removing the tert-octyl groups of 5-aminoimidazo[1,2-a]imidazoles 4a–d and 5a–g using TFA as cleavage agent in DCM and giving access to the primary amine compounds 8a–d and 9a–g, respectively, with yields ranging from 26 to 79% (Table 6). In a similar way, the primary imine imidazo[1,2-a]imidazoles 10a, 10b, 10d, 10e, and 10g were prepared in good yields from their corresponding Schiff base derivatives 7a, 7b, 7d, 7e, and 7g by deprotection of tert-octyl groups using the same conditions (Table 7). Unfortunately, the reaction was unsuccessful when the substituent R1 was 2,4,6-trimethoxyphenyl (entry 3) or ethyl (entry 6).
Conclusion
In summary, we have designed highly efficient protocols of multicomponent isocyanide-based reactions catalyzed by zirconium(IV) chloride which offer the synthesis of a library of new functionalized 5-amino and 5-iminoimidazo[1,2-a]imidazoles in moderate to good yields. The optimized processes were successively applied to a large number of substituted (or unsubstituted) 2-aminoimidazoles, aldehydes and isocyanides. In addition, the use of inexpensive zirconium(IV) chloride as catalyst delivered an efficient catalytic effect for the reactions with a greater purity of isolated products compared to other catalysts.
Data Availability
All datasets generated for this study are included in the manuscript and/or the Supplementary Files.
Author Contributions
MD designed and performed the experiments, then was responsible for writing the manuscript. RG realised the X-ray analysis for the compound 4a. PB and GG directed the project and revised the manuscript.
Conflict of Interest Statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Acknowledgments
We acknowledge Région Centre-Val de Loire for financial support and Dr. Cyril Colas (ICOA, University of Orléans) for HRMS measurements of our products.
Supplementary Material
The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fchem.2019.00457/full#supplementary-material
References
Abdelraheem, E. M. M., Madhavachary, R., Rossetti, A., Kurpiewska, K., Kalinowska-Tłuścik, J., Shaabani, S., et al. (2017). Ugi multicomponent reaction based synthesis of medium-sized rings. Org. Lett. 19, 6176–6179. doi: 10.1021/acs.orglett.7b03094
Adib, M., Sheibani, E., Zhu, L.-G., and Bijanzadeh, H. R. (2008). Efficient synthesis of imidazo[2,1-b][1,3]benzothiazoles and 9H-imidazo-[1,2-a][1,3]benzimidazoles under solvent-free Conditions. Synlett 2008, 2941–2944. doi: 10.1055/s-0028-1083623
Arnould, M., Hiebel, M.-A., Massip, S., Léger, J.-M., Jarry, C., Berteina-Raboin, S., et al. (2013). Efficient metal-free synthesis of various pyrido[2′,1′:2,3]imidazo-[4,5-b]quinolones. Chem. Eur. J. 19, 12249–12253. doi: 10.1002/chem.201300961
Bariwal, J., Kaur, R., Voskressensky, L. G., and Van der Eycken, E. V. (2018). Post-Ugi cyclization for the construction of diverse heterocyclic compounds: recent updates. Front. Chem. 6:527. doi: 10.3389/fchem.2018.00557
Baviskar, A. T., Madaan, C., Preet, R., Mohapatra, P., Jain, V., Agarwal, A., et al. (2011). N-Fused imidazoles as novel anticancer agents that inhibit catalytic activity of topoisomerase IIα and induce apoptosis in G1/S phase. J. Med. Chem. 54, 5013–5030. doi: 10.1021/jm200235u
Bienayme, H., and Bouzid, K. (1998). A new heterocyclic multicomponent reaction for the combinatorial synthesis of fused 3-aminoimidazoles. Angew. Chem. Int. Ed. 37, 2234–2237.
Blackburn, C. (1998). A three-component solid-phase synthesis of 3-aminoimidazo[1,2-a] azines. Tetrahedron Lett. 39, 5469–5472. doi: 10.1016/S0040-4039(98)01113-7
Brullo, C., Spisani, S., Selvatici, R., and Bruno, O. (2012). N-Aryl-2-phenyl-2,3-dihydro-imidazo[1,2-b]pyrazole-1-carboxamides 7-substituted strongly inhibiting both fMLP-OMe- and IL-8-induced human neutrophil chemotaxis. Eur. J. Med. Chem. 47, 573–579. doi: 10.1016/j.ejmech.2011.11.031
Bruno, O., Brullo, C., Bondavalli, F., Ranise, A., Schenone, S., Falzarano, M. S., et al. (2007). 2-Phenyl-2,3-dihydro-1H-imidazo[1,2-b]pyrazole derivatives: new potent inhibitors of fMLP-induced neutrophil chemotaxis. Bioorg. Med. Chem. Lett. 17, 3696–3701. doi: 10.1016/j.bmcl.2007.04.036
Castanedo, G., Liu, Y., Crawford, J. J., and Braun, M.-G. (2016). Synthesis of fused imidazole-containing ring systems via dual oxidative amination of C(sp3)–H bonds. J. Org. Chem. 81, 8617–8624. doi: 10.1021/acs.joc.6b01517
Chen, F., Lei, M., and Hu, L. (2013). Thiamine hydrochloride (VB1)-catalyzed one-pot synthesis of (E)-N-benzylidene-2-phenyl-1H-benzo[d]imidazo[1,2-a]imidazol-3-amine derivatives. Tetrahedron 69, 2954–2960. doi: 10.1016/j.tet.2013.02.022
Compernolle, F., and Toppet, S. J. (1986). Synthesis of 1H-imidazo[1,2-a]imidazole. J. Heterocycl. Chem. 23, 541–544. doi: 10.1002/jhet.5570230246
Devi, N., Rawal, R. K., and Singh, V. (2015). Diversity-oriented synthesis of fused-imidazole derivatives via Groebke–Blackburn–Bienayme reaction: a review. Tetrahedron 71, 183–232. doi: 10.1016/j.tet.2014.10.032
Dömling, A. (2006). Recent developments in isocyanide based multicomponent reactions in applied chemistry. Chem. Rev. 106, 17–89. doi: 10.1021/cr0505728
Dömling, A., and Ugi, I. (2000). Multicomponent reactions with isocyanides. Angew. Chem. Int. Ed. 39, 3168–3210. doi: 10.1002/1521-3773(20000915)39:18<3168::AID-ANIE3168>3.0.CO;2-U
Driowya, M., Allouchi, H., Gally, J. M., Bonnet, P., and Guillaumet, G. (2018). Synthesis of novel series of 7,7′-(substituted methylene)bis-imidazo[1,2-b]pyrazoles via an acid catalyzed one-pot three-component reaction. New J. Chem. 42, 5728–5741. doi: 10.1039/C7NJ05088G
El Akkaoui, A., Hiebel, M.-A., Mouaddib, A., Berteina-Raboin, S., and Guillaumet, G. (2012). Straightforward Bienaymé and copper catalyzed N-arylation sequence to access diverse 5H-pyrido[2′,1′:2,3]imidazo[4,5-b]indoles and analogues. Tetrahedron 68, 9131–9138. doi: 10.1016/j.tet.2012.07.081
Elleder, D., Baiga, T. J., Russell, R. L., Naughton, J. A., Hughes, S. H., Noel, J. P., et al. (2012). Identification of a 3-aminoimidazo[1,2-a]pyridine inhibitor of HIV-1 reverse transcriptase. Virol. J. 9, 305–311. doi: 10.1186/1743-422X-9-305
Fujimoto, T., Tobisu, M., Konishi, N., Kawamura, M., Tada, N., Takagi, T., et al. (2009). Synthesis and biological evaluation of the metabolites of 2-(1-{3-[(6-chloronaphthalen-2-yl)sulfonyl]propanoyl} piperidin-4-yl)-5-methyl-1,2-dihydro-3H-imidazo[1,5-c]imidazol-3-one. Bioorg. Med. Chem. 17, 7993–8002. doi: 10.1016/j.bmc.2009.10.009
Groebke, K., Weber, L., and Mehlin, F. (1998). Synthesis of imidazo[1,2-a] annulated pyridines, pyrazines and pyrimidines by a novel three-component condensation. Synlett 1998, 661–664. doi: 10.1055/s-1998-1721
Grosse, E. S., Pillard, C., Bernard, P., and Guillaumet, G. (2013). Efficient C-7 or C-3/C-7 direct arylation of tri- or disubstituted imidazo[1,2-b]pyrazoles. Synlett. 24, 2095–2101. doi: 10.1055/s-0033-1339657
Grosse, S., Mathieu, V., Pillard, C., Massip, S., Marchivie, M., Jarry, C., et al. (2014). New imidazo[1,2-b]pyrazoles as anticancer agents: synthesis, biological evaluation and structure activity relationship analysis. Eur. J. Med. Chem. 84, 718–730. doi: 10.1016/j.ejmech.2014.07.057
Grosse, S., Pillard, C., Massip, S., Léger, J. M., Jarry, C., Bourg, S., et al. (2012). Efficient synthesis and first regioselective C-3 direct arylation of imidazo[1,2-b]pyrazoles. Chemistry 18, 14943–14947. doi: 10.1002/chem.201202593
Grosse, S., Pillard, C., Massip, S., Marchivie, M., Jarry, C., Bernard, P., et al. (2015). Ligandless palladium-catalyzed regioselective direct C–H arylation of imidazo[1,2-a]imidazole derivatives. J. Org. Chem. 80, 8539–8551. doi: 10.1021/acs.joc.5b00534
Guchhait, S. K., and Madaan, C. (2009). An efficient, regioselective, versatile synthesis of N-fused 2- and 3-aminoimidazoles via Ugi-type multicomponent reaction mediated by zirconium(IV) chloride in polyethylene glycol-400. Synlett 4, 628–632. doi: 10.1055/s-0028-1087915
Han, X., Michne, J. A., Pin, S. S., Burris, K. D., Balanda, L. A., Fung, L. K., et al. (2005). Synthesis, structure–activity relationships, and anxiolytic activity of 7-aryl-6,7-dihydroimidazoimidazole corticotropin-releasing factor 1 receptor antagonists. Bioorg. Med. Chem. Lett. 15, 3870–3873. doi: 10.1016/j.bmcl.2005.05.117
Imaeda, Y., Kuroita, T., Sakamoto, H., Kawamoto, T., Tobisu, M., Konishi, N., et al. (2008). Discovery of imidazo[1,5-c]imidazol-3-ones: weakly basic, orally active factor Xa inhibitors. J. Med. Chem. 51, 3422–3436. doi: 10.1021/jm701548u
Kaur, T., Wadhwa, P., Bagchi, S., and Sharma, A. (2016). Isocyanide based [4+1] cycloaddition reactions: an indispensable tool in multi-component reactions (MCRs). Chem. Commun. 52, 6958–6976. doi: 10.1039/C6CC01562J
Kheder, N. A., and Farghaly, T. A. R. (2017). Bis-Hydrazonoyl chloride as precursors for synthesis of novel polysubstituted bis-azoles. Arab. J. Chem. 10, S3007–S3014. doi: 10.1016/j.arabjc.2013.11.040
Kolar, P., and Tisler, M. (1995). A new synthetic approach for imidazo[1,2-a]imidazoles and pyrrolo[1,2-a]imidazoles. J. Heterocycl. Chem. 32, 141–144. doi: 10.1002/jhet.5570320123
Langer, P., Wuckelt, J., Döring, M., Schreiner, P. R., and Görls, H. (2001). Regioselective anionic [3+2] cyclizations of imidazole dinucleophiles with oxaldiimidoyl dichlorides – a combined experimental and theoretical study. Eur. J. Org. Chem. 2245–2255. doi: 10.1002/1099-0690(200106)2001:12<2245::AID-EJOC2245>3.0.CO;2-C
Lila, T., Renau, T. E., Wilson, L., Philips, J., Natsoulis, G., Cope, M. J., et al. (2003). Molecular basis for fungal selectivity of novel antimitotic compounds. Antimicrob. Agents Chemother. 47, 2273–2282. doi: 10.1128/AAC.47.7.2273-2282.2003
Loubidi, M., Pillard, C., El Hakmaoui, A., Bernard, P., Akssira, M., and Guillaumet, G. (2016). A new synthetic approach to the imidazo[1,5-a]imidazole-2-one scaffold and effective functionalization through Suzuki–Miyaura cross coupling reactions. RSC Adv. 6, 7229–7238. doi: 10.1039/C5RA25520A
Mas, T., Claramunt, R. M., Santa María, M. D., Sanz, D., Alarcón, S. H., Pérez-Torralba, M., et al. (2002). Structure and spectroscopy of imidazo [1,2-a]imidazoles and imidazo[1,2-a]benzimidazoles. Arkivoc 2002, 48–61. doi: 10.3998/ark.5550190.0003.507
Mascitti, V., McClure, K. F., Munchhof, M. J., and Robinson, R. P. (2011). Imidazo-pyrazoles as GPR119 Inhibitors. WO Patent 2011/061679 A1.
Meta, E., Brullo, C., Sidibe, A., Imhof, B. A., and Bruno, O. (2017). Design, synthesis and biological evaluation of new pyrazolyl-ureas and imidazopyrazolecarboxamides able to interfere with MAPK and PI3K upstream signaling involved in the angiogenesis. Eur. J. Med. Chem. 133, 24–35. doi: 10.1016/j.ejmech.2017.03.066
Murlykina, M. V., Morozova, A. D., Zviagin, I. M., Sakhno, Y. I., Desenko, S. M., and Chebanov, V. A. (2018). Aminoazole-based diversity-oriented synthesis of heterocycles. Front. Chem. 6:527. doi: 10.3389/fchem.2018.00527
Pereshivko, O. P., Peshkov, V. A., Ermolat'ev, D. S., and Van der Eycken, E. V. (2013). Fast assembly of 1H-imidazo[1,2-a]imidazol-5-amines via Groebke–Blackburn–Bienaymé reaction with 2-aminoimidazoles. Synlett 24, 351–354. doi: 10.1055/s-0032-1317986
Poje, N., and Poje, M. (2003). An unusual oxidative ring transformation of purine to imidazo[1,5-c]imidazole. Org. Lett. 5, 4265–4268. doi: 10.1021/ol035429k
Saima, Y., Khamarui, S., Gayen, K. S., Pandit, P., and Maiti, D. K. (2012). Efficient catalytic cyclizations of three and two imine assemblies: direct access to tetrahydroimidazo[1,5-c]imidazol-7-ones and imidazoles. Chem. Commun. 48, 6601–6603. doi: 10.1039/c2cc32760k
Shaaban, S., and Abdel-Wahab, B. F. (2016). Groebke–Blackburn–Bienaymé multicomponent reaction: emerging chemistry for drug discovery. Mol. Divers. 20, 233–254. doi: 10.1007/s11030-015-9602-6
Shaabani, A., and Hooshmand, S. E. (2016). Choline chloride/urea as a deep eutectic solvent/organocatalyst promoted three-component synthesis of 3-aminoimidazo-fused heterocycles via Groebke–Blackburn–Bienayme process. Tetrahedron Lett. 57, 310–313. doi: 10.1016/j.tetlet.2015.12.014
Sidduri, A., Budd, D. C., Fuentes, M. E., Lambros, T., Ren, Y., Roongta, V., et al. (2014). Discovery of novel non-carboxylic acid 5-amino-4-cyanopyrazole derivatives as potent and highly selective LPA1R antagonists. Bioorg. Med. Chem. Lett. 24, 4450–4454. doi: 10.1016/j.bmcl.2014.08.001
Tber, Z., Hiebel, M.-A., Allouchi, H., El Hakmaoui, A., Akssira, M., Guillaumet, G., et al. (2015a). Metal free direct formation of various substituted pyrido[2′,1′:2,3]imidazo[4,5-c]isoquinolin-5-amines and their further functionalization. RSC Adv. 5, 35201–35210. doi: 10.1039/C5RA03703D
Tber, Z., Hiebel, M.-A., El Hakmaoui, A., Akssira, M., Guillaumet, G., and Berteina-Raboin, S. (2015b). Metal free formation of various 3-iodo-1H-pyrrolo[3′,2′:4,5]imidazo-[1,2-a]pyridines and [1,2-b]pyridazines and their further functionalization J. Org. Chem. 80, 6564–6573. doi: 10.1021/acs.joc.5b00555
Tellew, J. E., and Luo, Z. (2008). Small molecule antagonists of the corticotropin releasing factor (CRF) receptor: recent medicinal chemistry developments. Curr. Top. Med. Chem. 8, 506–520. doi: 10.2174/156802608783955665
Zhang, X., Allan, G. F., Sbriscia, T., Linton, O., Lundeen, S. G., and Sui, Z. (2006). Synthesis and SAR of novel hydantoin derivatives as selective androgen receptor modulators. Bioorg. Med. Chem. Lett. 16, 5763–5766. doi: 10.1016/j.bmcl.2006.08.084
Zuev, D., Vrudhula, V. M., Michne, J. A., Dasgupta, B., Pin, S. S., Huang, X. S., et al. (2010). Discovery of 6-chloro-2-trifluoromethyl-7-aryl-7H-imidazo[1,2-a]imidazol-3-ylmethylamines, a novel class of corticotropin-releasing factor receptor type 1 (CRF1R) antagonists. Bioorg. Med. Chem. Lett. 20, 3669–3674. doi: 10.1016/j.bmcl.2010.04.094
Keywords: multicomponent reactions, isocyanide Ugi reaction, zirconium(IV) chloride, catalysis, N-heterocycles, fused-ring systems, 2-aminoimidazole
Citation: Driowya M, Guillot R, Bonnet P and Guillaumet G (2019) Development of Novel and Efficient Processes for the Synthesis of 5-Amino and 5-Iminoimidazo[1,2-a]imidazoles via Three-Component Reaction Catalyzed by Zirconium(IV) Chloride. Front. Chem. 7:457. doi: 10.3389/fchem.2019.00457
Received: 14 March 2019; Accepted: 07 June 2019;
Published: 08 July 2019.
Edited by:
Alexander Dömling, University of Groningen, NetherlandsReviewed by:
Valentine Nenajdenko, Lomonosov Moscow State University, RussiaEgle Maria Beccalli, University of Milan, Italy
Copyright © 2019 Driowya, Guillot, Bonnet and Guillaumet. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Gérald Guillaumet, Z2VyYWxkLmd1aWxsYXVtZXQmI3gwMDA0MDt1bml2LW9ybGVhbnMuZnI=