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10Макроциклические полиамины МаКрОГЭТерОЦ^КЛЬ]
Статья
Macrocyclic polyamines
http://macroheterocycles.isuct.ru
Paper
DOI: 10.6060/mhc121215a
Palladium-Catalyzed Amination in the Synthesis of Macrocycles Comprising Two Naphthalene And Two Polyamine Moieties
Alexei N. Uglov,a Alexei D. Averin,ab@ Alexei K. Buryak,b Alla Bessmertnykh-Lemeune,c Roger Guilard,c and Irina P. Beletskayaab
aLomonosov Moscow State University, Department of Chemistry, 119991 Moscow, Russia hA.N. Frumkin Institute of Physical and Electrochemistry, 119991 Moscow, Russia
cInstitut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 5260, 21078 Dijon Cedex, France @Corresponding author E-mail: averin@org.chem.msu.ru
Two approaches were elaborated for the synthesis of macrocycles comprising two naphthalene and two polyamine moieties (cyclodimers). The first one includes the synthesis of N,N'-bis(7-bromonaphth-2-yl) substituted polyamines via Pd-catalyzed amination reaction of polyamine with excess of 2,7-dibromonaphthalene, followed by the Pd-catalyzed macrocyclization reaction with appropriate polyamine. The second route comprises the formation of 2,7-bis(polyamine) substituted naphthalenes which are used in situ for the macrocyclization with 2,7-dibromonaphthalene. The yields of cyclodimers are dependent on the nature of polyamines and catalytic systems employed. The two synthetic routes were compared and the one-pot method was found to be advantageous providing better yields of the target products.
Keywords: Palladium-catalized amination, naphthalene, polyamines, macrocycles, synthesis.
Палладий-катализируемое аминирование в синтезе макроциклов с двумя нафталиновыми и двумя полиаминными фрагментами
А. Н. Углов,a А. Д. Аверин,^ А. К. Буряк^ А. Бессмертных-Лемен^ Р. Гиляр^ И. П. Белецкая^
Московский государственный университет им. М. В. Ломоносова, Химический факультет, 119991 Москва, Россия ьИнститут физической химии и электрохимии им. А. Н. Фрумкина РАН, 119991 Москва, Россия cInstitut de Chimie Moléculaire de l'Université de Bourgogne (ICMUB), UMR CNRS 5260, 21078 Дижон, Франция @E-mail: averin@org.chem.msu.ru
Разработаны два подхода к синтезу макроциклов, содержащих по два фрагмента нафталина и полиамина (циклодимеров). Первый подход заключается в первоначальном получении N,N'-бис(7-бромнафт-2-ил) замещенных полиаминов Pd-катализируемым аминированием избытка 2,7-дибромнафталина полиаминами с последующей Pd-катализируемой макроциклизацией данных соединений с использованием соответствующих полиаминов. Второй подход заключается в синтезе 2,7-бис(полиамино)замещенных нафталинов, которые используются in situ на второй стадии макроциклизации. Найдено, что выходы макроциклов зависят от природы полиамина, в определенных случаях показано предпочтительное использование фосфиновых лигандов BINAP или Xantphos, произведено сравнение эффективности двух предложенных методов, установлено, что второй метод дает в целом более высокие выходы целевых циклодимеров. Выделены и охарактеризованы циклические и линейные побочные продукты в указанных реакциях.
Ключевые слова: Палладий-катализируемое аминирование, нафталин, полиамины, макроциклы, синтез.
Introduction
Worldwide applications of coordination chemistry in the development of chemotherapeutic or diagnostic agents, treatment of nuclear waste, chemosensoring have become of paramount importance and progress rapidly in comparison with the studies that elucidate the basic theory of this field. Therefore, the research is often carried out in a make-and-try manner and numerous ligands have been synthesized and their affinity to metal cations has been evaluated. Ideally, efficient ligands should match various criteria such as high binding constants and selectivity together with fast binding kinetics of the coordination pocket, water solubility, insensitivity to p^ changes, non-toxicity, etc. Complex molecular architectures should be synthesized to adopt the system properties to a real-life application. Ligand properties could be tuned not only by varying the number and nature of donor groups but also by introducing different non-coordinated structural motifs. Aromatic moieties are of major interest in ligand design for chemosensoring and sequestration of toxic and radioactive metal ions. The first macrocyclic compounds comprising the naphthalene moiety were described in the literature over 70 years ago.[1] This rigid lipophilic fragment possessing interesting photophysical properties draws considerable interest and dozen of works appeared dealing with the synthesis and investigation of the macrocycles of different geometry based on naphthalene, as well with the azacrown ethers derivatives containing naphthalene as exocyclic substituents. In these polyazacycles nitrogen atoms are present in such fragments as Schiff bases,[2] diamides,[3] diimides,[4] lactames.[5] Naphthalene system can be condensed with tetraazamacrocycles,[6] macrocycles may contain phosphorus atoms[7] or only carbon atoms,[8] it can be incorporated into calixarene[9] and catenane[10] structures, combined in various manners with porphyrins. [11] Such compounds are valuable molecular precursors for supramolecular studies and could be used e.g. as organic anions receptors[12] or molecular rotors.[13]
Recently, we have synthesized a series of the nitrogen- and oxygen-containing macrocycles based on 2,7-diaminonaphthalene (Scheme 1).[14] Herein we report a detailed account on the synthesis of macrocyclic compounds composed by two aromatic groups and two linear chains (so-called cyclodimers).
Experimental
NMR spectra were registered using Bruker Avance 400 spectrometer, MALDI-TOF spectra were obtained with Bruker Ultraflex spectrometer using 1,8,9-trihydroxyanthracene as matrix and PEGs as internal standards. Dioxa- and trioxadiamines, tetraamine, BINAP and Xantphos ligands, sodium tert-butoxide were purchased from Aldrich and Acros and used without further purification, 2,7-dibromonaphthalene was obtained according to a reported procedure,[15] Pd(dba)2 was synthesized according to the method described.[16] Dioxane was distilled over NaOH followed by the distillation over sodium under argon, acetonitrile, dichloromethane and methanol were used freshly distilled.
Typical procedure for the synthesis of N,N'-bis(7-bromonaphth-2-yl) substituted naphthalenes 4a-c.
A two-neck flask equipped with a condenser and magnetic stirrer, flushed with dry argon, was charged with 2,7-dibromonaphthalene
2 (629 mg, 2.2 mmol), Pd(dba)2 (11.5 mg, 0.02 mmol, 2 mol%) and Xantphos (15 mg, 0.025 mmol, 2.5 mol%) in the case of dioxa- and trioxadiamines 1a,b, or Pd(dba)2 (23 mg, 0.04 mmol, 4 mol%) and BINAP (28 mg, 0.045 mmol, 4.5 mol%) in the case of tetraamine 1c, 20 ml (in the case of dioxa- and trioxadiamines 1a,b) or 10 ml (in the case of tetraamine 1c) dioxane were added, the mixture was stirred for 2-3 min, then corresponding polyamine 1a-c (1 mmol) and "BuONa (288 mg, 3 mmol) were added, and the reaction mixture was refluxed for 5-8 h. After cooling it down to ambient temperature the reaction mixture was diluted with CH^C^, the residue was filtered off, the organic solvents were evaporated in vacuo, and the residue was chromatographed on silica gel using a sequence of eluents: CH^, CH^/MeOH (200:13:1), CH2Cl2/MeOH/NH3aq (100:20:1-10:4:1).
N,N'-(2,2'-(Ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl)) bis(7-bromonaphthalene-2-amine), 4a. Obtained from 148 mg of dioxadiamine 1a. Eluent CHp/MeOH 500:1-200:1. Yield 150 mg (27 %), yellowish glassy compound. (MALDI-TOF) found: 557.0391. C^B^N^ requires 557.0439 [M+H]+. 'H NMR (CDCl3, 298 K) SH ppm: 3.38 (4H, t, 3J = 5.1 Hz), 3.69 (4H, s), 3.77 (4H, t, 3J = 5.1 Hz), 4.35 (2H, br.s), 6.66 (2H, d, 4J = 2.0 Hz), 6.83 (2H, dd, 3J = 8.8 Hz, 4J = 2.2 Hz), 7.23 (2H, dd, 3J = 8.7 Hz, 4J = 1.9 Hz), 7.47-7.57 (4H, m), 7.72 (2H, br.s). 13C NMR (CDCl3, 298 K) Sc ppm: 43.3 (2C), 69.4 (2C), 70.3 (2C), 103.4 (2C), 118.4 (2C), 120.5 (2C), 125.2 (2C), 126.0 (2C), 127.8 (2C), 128.9 (2C), 129.3 (2C), 136.4 (2C), 146.6 (2C).
N,N,N,'-Tris(7-bromonaphth-2-yl)substituted dioxadiamine 8a was obtained as the second product in the synthesis of compound 4a. Eluent CH2Cl2. Yield 50 mg (10 %), yellowish glassy compound. (MALDI-TOF) found: 761.0087. C^B^N^ requires 761.0014 [M+H]+. 1H NMR (CDCl3, 298 K) SH ppm: 3.30 (2H, t, 3J = 5.2 Hz), 3.63 (4H, s), 3.70 (2H, t, 3J = 5.2 Hz), 3.79 (2H, t, 3J = 5.9 Hz), 4.15 (2H, t, 3J = 5.8 Hz), 4.26 (1H, br.s), 6.61 (1H, d, 4J = 1.6 Hz), 6.74 (1H, dd, 3J = 8.7 Hz, 4J = 2.3 Hz), 7.26 (1H, dd, 3J = 9.0 Hz, 4J = 1.9 Hz), 7.27 (2H, dd, 3J = 9.0 Hz, 4J = 2.1 Hz), 7.36 (2H, d, 4J = 1.8 Hz), 7.39 (2H, dd, 3J = 8.7 Hz, 4J = 1.9 Hz), 7.48 (2H, d, 3J = 8.9 Hz), 7.57 (2H, d, 3J = 8.7 Hz), 7.64 (2H, d, 3J = 9.0 Hz), 7.72 (1H, br.s), 7.82 (2H, br.s). 13C NMR (CDCl3, 298 K) Sc ppm: 43.2 (1C), 52.1 (1C), 68.2 (1C), 69.4 (1C), 70.4 (1C), 70.8 (1C), 103.3 (1C), 115.5 (2C), 118.4 (1C), 120.4 (1C), 120.6 (2C), 122.8 (2C), 125.1 (1C), 125.8 (1C), 127.4 (2C), 127.8 (1C), 128.4 (2C), 128.7 (2C), 128.8 (1C), 128.9 (2C), 129.1 (2C), 129.2 (1C), 135.7 (2C), 136.4 (1C), 145.8 (2C), 146.5 (1C).
Oligomer 9a was obtained as the third product in the synthesis of compound 4a. Eluent CH2Cl2/MeOH 100:1. Yield 55 mg (13 %), yellowish glassy compound. (MALDI-TOF) found: 829.1922. C42H47Br2N4O4 requires 829.1964 [M+H]+. 1H NMR (CDCl3, 298 K) SH ppm: 3.37 (8H, t, 3J = 5.0 Hz), 3.67 (8H, s), 3.75 (4H, t, 3J = 4.6 Hz), 3.76 (4H, t, 3J = 4.9 Hz), 4.11 (2H, br.s), 4.37 (2H, br.s), 6.60 (2H, d, 3J = 8.0 Hz), 6.61 (2H, br.s), 6.65 (2H, d, 4J = 1.9 Hz), 6.83 (2H, dd, 3J = 8.6 Hz, 4J = 2.0 Hz), 7.23 (2H, dd, 3J = 8.2 Hz, 4J = 1.4 Hz), 7.40 (2H, d, 3J = 9.1 Hz), 7.47 (2H, d, 3J = 8.3 Hz), 7.50 (2H, d, 3J = 8.7 Hz), 7.72 (2H, br.s). 13C NMR (CDCl3, 298 K) Sc ppm: 43.3 (2C), 43.5 (2C), 69.3 (2C), 69.6 (2C), 70.2 (2C), 70.3 (2C), 103.3 (2C), 103.6 (2C), 114.2 (2C), 118.5 (2C), 120.4 (2C), 125.1 (2C), 125.8 (2C), 127.8 (2C), 128.8 (2C), 128.9 (2C), 129.2 (2C), 136.4 (2C), 146.3 (2C), 146.6 (2C), two quaternary carbon atoms were not assigned.
N,N'-(3,3'-(2,2'-Oxybis(ethane-2,1-diyl)bis(oxy))bis(pro-pane-3,1-diyl))bis(7-bromonaphthalene-2-amine), 4b. Obtained from 220 mg of trioxadiamine 1b. Eluent CH2Cl2/MeOH 200:1. Yield 235 mg (37 %), yellowish glassy compound. (MALDI-TOF) found: 628.21. C^H^N^ requires 628.09 [M]+. 1H NMR (CDCl3, 298 K) SH ppm: 1.92 (4H, quintet, 3J = 5.9 Hz), 3.29 (4H, t, 3J = 6.2 Hz), 3.62 (4H, t, 3J = 5.5 Hz), 3.61-3.65 (4H, m), 3.67-3.72 (4H, m), 4.37 (2H, br.s), 6.62 (2H, br.s), 6.81 (2H, d, 3J = 8.8 Hz), 7.21 (2H, d, 3J = 8.6 Hz), 7.47 (2H, d, 3J = 8.6 Hz), 7.51 (2H, d, 3J = 8.9 Hz), 7.72 (2H, br.s). 13C NMR (CDCl3, 298 K) Sc ppm: 28.8 (2C), 41.8 (2C), 69.9 (2C), 70.3 (2C), 70.7 (2C), 102.7 (2C), 118.5
A. D. Averin et al.
(2С), 120.4 (2С), 124.8 (2С), 125.6 (2С), 127.7 (2С), 128.7 (2С), 129.3 (2С), 136.6 (2С), 147.0 (2С).
N,N,N,'-Tris(7-bromonaphth-2-yl)substituted trioxadiamine 8b was obtained as the second product in the synthesis of compound 4b. Eluent CH2Cl2/MeOH 200:1. Yield 67 mg (10 %), yellowish glassy compound. (MALDI-TOF) found: 832.13. C4(,H39Br3N2O3 requires 832.05 [M]+. 1H NMR (CDCl3, 298 K) SH ppn0: 1.91 (2Н, quintet, 3J = 6.0 Hz), 1.99 (2Н, quintet, 3J = 6.3 Hz), 3.28 (2Н, t, 3J = 6.3 Hz), 3.55 (2Н, t, 3J = 5.7 Hz), 3.63 (2Н, t, 3J = 5.6 Hz), 3.63-3.66 (4Н, m), 3.71-3.75 (4Н, m), 4.05 (2Н, t, 3J = 6.9 Hz), 4.39 (1Н, br.s), 6.61 (1Н, d, 4J = 1.9 Hz), 6.81 (1Н, dd, 3J = 8.8 Hz, 4J = 2.1 Hz), 7.21 (1Н, dd, 3J = 8.7 Hz, 4J = 2.0 Hz), 7.24 (2Н, dd, 3J = 8.7 Hz, 4J = 2.1 Hz), 7.31 (2Н, d, 4J = 1.9 Hz), 7.39 (2Н, dd, 3J = 8.7 Hz, 4J = 1.8 Hz), 7.46 (1Н, d, 3J = 8.6 Hz), 7.50 (1Н, d, 3J = 8.8 Hz), 7.58 (2Н, d, 3J = 8.5 Hz), 7.64 (2Н, d, 3J = 9.0 Hz), 7.72 (1Н, d, 4J = 1.5 Hz), 7.83 (2Н, br.s). 13C NMR (CDCl3, 298 K) Sc ppm: 27.5 (1С), 28.8 (1С), 41.7 (1С), 49.1 (1С), 68.2 (1С), 69.8c(1C), 70.3 (2С), 70.7 (2С), 102.6 (1С), 115.3 (2С), 118.4 (1С), 120.4 (3С), 122.8 (2С), 124.7 (1С), 125.5 (1С), 127.2 (2С), 127.6 (1С), 127.7 (2С), 128.6 (1С), 128.7 (2С), 128.8 (2С), 129.1 (2С), 129.2 (1С), 135.8 (2С), 136.5 (1С), 146.0 (2С), 146.9 (1С).
Oligomer 9b was obtained as the third product in the synthesis of compound 4b. Eluent CH2Cl2/MeOH 100:1. Yield 29 mg (6 %), yellowish glassy compound. (MALDI-TOF) found: 972.44. C50H62Br2N4O6 requires 972.30 [M]+. 1H NMR (CDCl3, 298 K) SH ppm: 1.91 (4Н, quintet, 3J = 5.7 Hz), 1.92 (4Н, quintet, 3J = 5.8 Hz), 3.27 (4Н, t, 3J = 5.8 Hz), 3.28 (4H,t, 3J = 6.2 Hz), 3.61 (8Н, t, 3J = 5.7), 3.61-3.65 (8Н, m), 3.66-3.71 (8Н, m), 4.33 (4Н, br.s), 6.57 (2Н, dd, 3J = 8.7 Hz, 4J = 2.0 Hz), 6.58 (2Н, br.s), 6.61 (2Н, br.s), 6.81 (2Н, dd, 3J = 8.7 Hz, 4J = 2.1 Hz), 7.20 (2Н, dd, 3J = 8.4 Hz, 4J = 1,8 Hz), 7.40 (2Н, d, 3J = 8.6 Hz), 7.46 (2Н, d, 3J = 8.6 Hz), 7.51 (2Н, d, 3J = 8.9 Hz), 7.72 (2Н, br.s). 13C NMR (CDCl3, 298 K) Sc ppm: 28.8 (2С), 29.0 (2С), 41.7 (4С), 69.8 (4С), 70.2 (4С), 70.6 (4С), 102.6 (2С), 102.9 (2С), 113.8 (2С), 118.4 (2С), 120.3 (2С), 121.2 (1С), 124.7 (2С), 125.5 (2С), 127.6 (2С), 128.6 (2С), 128.7 (2С), 129.2 (2С), 136.6 (2С), 137.0 (1С), 146.7 (2С), 147.0 (2С).
N1,N1-(Ethane-1,2-diyl)bis(N3-(7-bromonaphthalene-2-yl) propane-l,3-diamine), 4c. Obtained from 174 mg of tetraamine 1c. Eluent CH2Cl2/MeOH/NH3aq 100:20:1. Yield 158 mg (27 %), yellowish glassy compound. (MALDI-TOF) found: 583.1025. C28H33Br2N4 requires 583.1072 [M+H]+. 1H NMR (CDCl3, 298 K) SH ppm: 1.79 (4Н, quintet, 3J = 6.5 Hz), 1.89 (2Н, br.s), 2.72 (4Н, s), 2.73 (4Н, t, 3J = 6.6 Hz), 3.21 (4Н, t, 3J = 6.5 Hz), 4.50 (2Н, br.s), 6.60 (2Н, d, 4J = 1.5 Hz), 6.80 (2Н, dd, 3J = 8.7 Hz, 4J = 2.2 Hz), 7.22 (2Н, dd, 3J = 8.6 Hz, 4J = 1.8 Hz), 7.46 (2Н, d, 3J = 8.6 Hz), 7.51 (2Н, d, 3J = 8.8 Hz), 7.73 (2Н, br.s). 13C NMR (CDCl3, 298 K) Sc ppm: 29.0 (2С), 42.4 (2С), 48.0 (2С), 49.3 (2С), 102.6 (2С),
118.2 (2С), 120.3 (2С), 124.7 (2С), 125.5 (2С), 127.6 (2С), 128.6 (2С), 129.2 (2С), 136.5 (2С), 146.8 (2С).
Oligomer 9c was obtained as the second product in the synthesis of compound 4c. Eluent CH2Cl2/MeOH/NH3aq 100:20:2. Yield 166 mg (37 %), yellowish glassy compound. (MALDI-TOF) found: 881.3156. C46H59Br2N8 requires 881.3229 [M+H]+. 1H NMR (CDCl3, 298 K) SH ppm: 1.76 (4Н, quintet 3J = 6.3 Hz), 1.77 (4Н, quintet, 3J = 6.0 Hz), 2.64-2.73 (16Н, m), 3.15 (4Н, t, 3J = 6.5 Hz), 3.19 (4Н, t, 3J = 6.3 Hz), 4.48 (4Н, br.s), 6.54-6.60 (6Н, m), 6.766.81 (2Н, m), 7.18-7.22 (2Н, m), 7.37-7.50 (6Н, m), 7.72 (2Н, br.s), NH protons of dialkylamino groups were not assigned. 13C NMR (CDCl3, 298 K) Sc ppm: 28.8 (2С), 28.9 (2С), 42.3 (2С), 42.4 (2С), 47.8 (2С), 47.9 (2С), 49.0 (4С), 102.5 (2С), 102.8 (2С), 113.7 (2С),
118.3 (2С), 120.2 (2С), 121.2 (1С), 124.6 (2С), 125.4 (2С), 127.5 (2С), 128.5 (2С), 128.6 (2С), 129.2 (2С), 136.5 (2С), 136.9 (1С), 146.6 (2С), 146.8 (2С).
Typical procedure for the synthesis of cyclodimers 7 from compounds 4.
A two-neck flask equipped with a condenser and magnetic stirrer, flushed with dry argon, was charged with compound 4a-c, Pd(dba)2 (8 mol%), BINAP (9 mol%) and dioxane to make 0.02 M
solution, the mixture was stirred for 2-3 min, then equimolar amount of appropriate polyamine 1a-c and tBuONa (3 equiv.) were added, and the reaction mixture was refluxed for 6-10 h. After cooling it down to ambient temperature the reaction mixture was diluted with CH2Cl2, the residue was filtered off, the organic solvents were evaporated in vacuo, and the residue was chromatographed on silica gel using a sequence of eluents: CH2Cl2, CH2Cl2/MeOH (200:1-3:1), CH2Cl2/MeOH/NH3aq (100:20:1-10:4:1).
Cyclic dimer 7a. Obtained from compound 4a (70 mg, 0.13 mmol), dioxadiamine 1a (19 mg, 0.13 mmol), in the presence of Pd(dba)2 (6 mg, 0.01 mmol), BINAP (7.3 mg, 0.012 mmol), tBuONa (37 mg, 0.39 mmol), in 6.5 ml dioxane. Eluent CH2Cl2/MeOH 75:1. Yield 8 mg (11 %), yellowish glassy compound. (MALDI-TOF) found: 544.3018. C32H40N4O4 requires 544.3050 [M]+. 1H NMR (CDCl3, 298 K) SH ppm: 3.28 (8Н, t, 3J = 5.2 Hz), 3.66 (8Н, s), 3.70 (8Н, t, 3J = 5.1 Hz), 4.15 (4Н, br.s), 6.44 (4Н, d, 4J = 2.1 Hz), 6.64 (4Н, dd, 3J = 8.8 Hz, 4J = 2.1 Hz), 7.41 (4Н, d, 3J = 8.7 Hz). 13C NMR (CDCl3, 298 K) Sc ppm: 43.6 (4С), 69.5 (4С), 70.2 (4С),
104.5 (4С), 113.3 (4С), 121c.7 (2С), 128.7 (4С), 136.8 (2С), 146.3 (4С).
Cyclic dimer 7b. Obtained from compound 4b (148 mg, 0.24 mmol), trioxadiamine 1b (52 mg, 0.24 mmol), in the presence of Pd(dba)2 (11 mg, 0.019 mmol), BINAP (13 mg, 0.021 mmol), tBuONa (70 mg, 0.72 mmol), in 12 ml dioxane. Eluent CH2Cl2/ MeOH 100:1-50:1. Yield 45 mg (28 %), yellowish glassy compound. (MALDI-TOF) found: 688.41. C40H56N4O6 requires 688.42 [M]+. 1H NMR (CDCl3, 298 K) SH ppm: 1.588 (8Н, quintet, 3J = 6.0 Hz), 3.27 (8Н, t, 3J = 6.4 Hz), 3.59 (8Н, t, 3J = 5.8 Hz), 3.59-3.62 (8Н, m), 3.66-3.70 (8Н, m), 4.12 (4Н, br.s), 6.51 (4Н, d, 4J = 1.9 Hz), 6.57 (4Н, dd, 3J = 8.6 Hz, 4J = 2.0 Hz), 7.39 (4Н, d, 3J = 8.7 Hz). 13C NMR (CDCl3, 298 K) Sc ppm: 29.1 (4С), 41.7 (4С), 69.6 (4С), 70.3 (4С), 70.7 (4С), 103.3 (4С), 113.6 (4С), 121.3 (2С), 128.5 (4С), 137.0 (2С), 146.7 (4С).
A mixture of cyclic tetramer and hexamer 10b (n = 3, 5) was obtained as by-product in the synthesis of the cyclic dimer 7b. Eluent CH2Cl2/MeOH 10:1. Yield 18 mg (11 %), yellowish glassy compound2 (MALDI-TOF) found: 1376.75. C80H112N8O12 requires 1376.84 [M]+ for 10b (n = 3). found: 2065.09. C120H168N12O18 requires 2065.26 [M]+ for 10b (n = 5). 1H NMR (CDCl3, 298 K) SH ppm: 1.89 (4(n+1)H, br.s), 3.26 (4(n+1)H, t, 3J = 5.7 Hz), 3.59 (8(n+1) Н, br.s), 3.66 (4(n+1)H, br.s), 6.54 (2(n+1)H, d, 3J = 9.3 Hz), 6.57 (2(n+1)H, br.s), 7.38 (2(n+1)H, d, 3J = 9.3 Hz), NH protons were not assigned. 13C NMR (CDCl3, 298 K) Sc ppm: 29.1 (2(п+1)С), 41.7 (2(п+1)с), 69.8 (2(п+1)с), 70.2 (2(п+1)с), 70.6 (2(п+1)с), 102.9 (2(п+1)С), 113.8 (2(п+1)С), 118.1 ((п+1)С), 128.5 (2(n+1) С), 137.0 ((п+1)с), 146.7 (2(п+1)с).
Cyclic dimer 7c. Obtained from compound 4c (158 mg, 0.3 mmol), tetraamine 1c (52 mg, 0.3 mmol), in the presence of Pd(dba)2 (14 mg, 0.024 mmol), BINAP (17 mg, 0.027 mmol), tBuONa (86 mg, 0.9 mmol), in 15 ml dioxane. Eluent CH2Cl2/ MeOH/NH3aq 100:20:3. Yield 37 mg (21 %), yellowish glassy compound. (MALDI-TOF) found: 596.4221. C36H52N8 requires 596.4314 [M]+. 1H NMR (CDCl3, 298 K) SH ppm: 1.73 (8Н, quintet, 3J = 6.2 Hz), 2.69 (8Н, t, 3J = 6.43 Hz), 2.71 (8Н, s), 3.19 (8Н, t, 3J = 6.4 Hz), 6.52-6.58 (8Н, m), 7.38 (4Н, d, 3J = 9.0 Hz), NH protons were not assigned. 13C NMR (CDCl3, 298 K) Sc ppm: 29.3 (4C), 42.7 (4C), 47.8 (4C), 48.9 (4C), 103.3 (4C), 113.5c (4C), 121.3 (2C),
128.6 (4C), 137.0 (2C), 146.7 (4C).
Cyclic tetramer 10c (n = 3) was obtained as the second product in the synthesis of the cyclic dimer 7c. Eluent CH2Cl2/MeOH/NH3aq 10:4:1. Yield 19 mg (11 %), yellowish glassy compound. (MALDI-TOF) found: 1192.83. C72H104N16 requires 1192.86 [M]+. 1H NMR (DMSO-d6, 298 K) SH ppm: 1.7-4 (16Н, br.s), 2.69 (32Н, br.s), 3.08 (16Н, br.s), 5.59 (8Н, br.s), 6.41 (8Н, br.s), 6.53 (8Н, d, 3J = 8.1 Hz), 7.26 (8Н, d, 3J = 8.1 Hz), NH protons of dialkylamino groups were not assigned. 13C NMR (DMSO-d6, 298 K) Sc ppm: 28.0 (8С), 41.0 (8С), 46.7 (8С), 47.5 (8С), 101.1 (8 С), 113.1 (8С), 119.7 (4С), 127.9 (8С), 137.1 (4С), 146.9 (8С).
Cyclic dimer 7ab. Obtained from compound 4b (105 mg, 0.17 mmol), dioxadiamine 1a (25 mg, 0.17 mmol), in the presence of Pd(dba)2 (8 mg, 0.014 mmol), BINAP (9 mg, 0.014 mmol), 'BuONa (49 mg, 0.51 mmol), in 8 ml dioxane. Eluent CH2Cl2/MeOH 50:1. Yield 14 mg (13 %), yellowish glassy compound. (MALDI-TOF) found: 616.50. C36H48N4O5 requires 616.36 [M]+. 1H NMR (CDCl3, 298 K) SH ppm: 1.91 (4H, quintet, 3J = 6.0 Hz), 3.26-3.40 (8H, m), 3.57-3.75 (20H, m), 4.13 (4H, br.s), 6.59-6.65 (8H, m), 7.40 (2H, d, 3J = 8.4 Hz), 7.42 (2H, d, J = 8.7 Hz). 13C NMR (CDCl3, 298 K) 5c ppm: 29.0 (2C), 41.7 (2C), 43.7 (2C), 69.5 (2C), 69.8 (2C), 70.2 c(4C), 70.6 (2C), 102.9 (2C), 103.5 (2C), 113.9 (2C), 114.0 (2C), 121.6 (2C), 128.5 (2C), 128.6 (2C), 136.9 (2C), 146.4 (2C), 146.7 (2C).
Typical procedure for 'he syn'hesis of cyclic dimers 7 via bis(polyamine) derivatives 5.
A two-neck flask equipped with a condenser and magnetic stirrer, flushed with argon, was charged with 2,7-dibromonaphtha-lene (14) mg, 0.5 mmol), Pd(dba)2 (11.5 mg, 0.02 mmol, 4 mol%), diphosphine ligand (15 mg of Xantphos or 14 mg of BINAP, 0.02) mmol, 4.5 mol%), 5 ml of dioxane. The mixture was stirred for 2-3 min, then appropriate polyamine 1a-c (2 mmol) and 'BuONa (144 mg, 1.5 mmol) were added and the reaction mixture was refluxed for 4-6 h. After cooling it down to ambient temperature an aliquot (0.5 ml) was taken and analyzed using NMR and MALDI-TOF spectroscopy. Then 2,7-dibromonaphthalene (386 mg, 1.35 mmol), Pd(dba)2 (62 mg, 0.11 mmol, 8 mol%), BINAP (76 mg, 0.12 mmol, 9 mol%), 20 ml abs. dioxane and 'BuONa (390 mg, 4 mmol) were added, and the reaction mixture was refluxed for 6-15 h. After cooling it down to ambient temperature the reaction mixture was diluted with CH2Cl2, the residue was filtered off, the organic solvents were evaporated in vacuo, and the residue was chromatographed on silica gel using a sequence of eluents: CH2Cl2, CH2Cl2/MeOH (200:1-3:1), CH2Cl2/MeOH/NH3aq (100:20:1-10:4:1).
N2,N7-Bis(2-(2-(2-aminoe'hoxy)e'hoxy)e'hyl)naph'halene-2,7-diamine, 5a. Obtained in si'u using Xantphos ligand and 296 mg of dioxadiamine 1a. (MALDI-TOF) found: 421.32. C22H37N4O4 requires 421.28 [M+H]+. 1H NMR (CDCl3, 298 K) SH ppm: 2.83 (4H, t, 3J = 5.2 Hz), 3.35 (4H, t, 3J = 4.9 Hz), 3.47 (4H, t, J = 5.2 Hz), 3.593.63 (8H, m), 3.72 (4H, t, 3J = 5.3 Hz), 4.23 (2H, br.s), 6.58-6.61 (4H, m), 7.41 (2H, d, 3J = 9.3 Hz). 13C NMR (CDCl3, 298 K) Sc ppm: 41.7 (2C), 43.4 (2C), 69.5 (2C), 70.2 (4C), 73.3 (2C), 103.3 (2C), 114.1 (2C), 121.6 (1C), 128.6 (2C), 136.7 (1C), 146.3 (2C).
Cyclic dimer 7a was synthesized from in si'u obtained compound 5a. Eluent CH2Cl2/MeOH 75:1. Yield 26 mg (10 %). Spectral data are given above. A mixture of cyclic trimer and tetramer 7a (n = 2, 3) was obtained as the side product. Eluent CH2Cl2/MeOH 50:1-20:1. Yield 58 mg (21 %). (MALDI-TOF) found: 816.41. C48H60N6O6 requires 816.46 [M]+ for 7a (n = 2). found: 1088.67. C64H80N8O8 requires 1088.60 [M]+ for 7a (n = 3). 1H NMR (CDCl3, 298 K) 5H ppm: 3.30-3.40 (4(n+1)H, m), 3.603.75 (8(n+1)H, m), 6.56-6.64 (4(n+1)H, m), 7.32-7.46 (2(n+1) H, m). 13C NMR (CDCl3, 298 K) 5c ppm: 43.4 (2(n+1)C), 69.4 + 69.5 (2(n+1)C), 70.1 (2(n+1)C), 103c.4 (2(n+1)C), 114.0 (2(n+1)C),
128.7 (2(n+1)C), 146.3 (2(n+1)c), 2(n+1) quaternary carbon atoms were not assigned.
N2,N7-Bis(3-(2-(2-(3-aminopropoxy)e'hoxy)e'hoxy)propyl)-naph'halene-2,7-diamine, 5b. Obtained in si'u using Xantphos ligand and 440 mg of trioxadiamine 1b. (MALDI-TOF) found: 565.44. C30H53N4O6 requires 565.40 [M+H]+. 1H NMR (CDCl3, 298 K) 5H ppm: 1.63 (4H, quintet, 3J = 6.5 Hz), 1.86 (4H, quintet, 3J = 6.1 Hz), 2.68 (4H, t, 3J = 6.8 Hz), 3.22 (4H, t, 3J = 6.5 Hz), 3.46 (4H, t, 3J = 6.2 Hz), 3.47-3.58 (20H, m), 6.48-6.52 (4H, m), 7.32 (2H, d, 3J = 8.3 Hz). 13C NMR (CDCl3, 298 K) Sc ppm: 28.8 (2C), 33.1 (2C), 39.2 (2C), 41.5 (2C), 69.3 (2C), 69.6c(4C), 70.0 (2C), 70.1 (2C), 70.4 (2C), 102.7 (2C), 113.6 (2C), 121.0 (1C), 128.3 (2C),
136.8 (1C), 146.5 (2C).
Cyclic dimer 7b was synthesized from in si'u obtained compound 5b. Eluent CH2Cl2/MeOH 50:1. Yield 104 mg (30 %).
Spectral data are given above. Macrocycle 6b was obtained as the side product. Eluent CH2Cl2/MeOH 200:1. Yield 100 mg (24 %). Spectral data are given in ref.[14] A mixture of cyclic trimer, tetramer and pentamer 10b (n = 2-4) was obtained as the side product. Eluent CH2Cl2/MeOH 20:1. Yield 90 mg (25 %). (MALDI-TOF) found: 1032.55. C60H84N6O9 requires 1032.63 [M]+ for 10b (n = 2). found: 1376.95. C80H112N8O12 requires 1376.84 [M]+ for 10b (n = 3). found: 1721.12. C1(X1H140N10O15 requires 1721.05 [M]+ for 10b (n = 4). 1H NMR (CDCl3, 2298 K) SH ppm: 1.91 (4(n+1)H, quintet, 3J = 6.1 Hz), 3.27 (t, 3J = 5.9 Hz) + 3.28 (t, 3J = 6.2 Hz) (4(n+1)H), 3.563.62 (8(n+1)H, m), 3.66-3.69 (4(n+1)H, m), 4.00 (2(n+1)H, br.s), 6.53-6.61 (4(n+1)H, m), 7.40 (d, 3J = 8.0 Hz) + 7.41 (d, 3J = 8.5 Hz) (2(n+1)H). 13C NMR (CDCl3, 298 K) Sc ppm: 29.0 (2(n+1)C), 41.6 (2(n+1)C), 69.7 (2(n+1)C), 70.1 (2(n+ 1)С), 70.5 (2(n+1)C), 102.8 (2(n+1)C), 113.7 (2(n+1)C), 121.2 ((n+1)C), 128.4 (2(n+1) С), 137.0 ((n+1)C), 146.6 (2(n+1)C).
N1,N1'-(Naphthalene-2,7-diyl)bis(N3-(3-(3-aminopropyl-amino)propyl)propane-l,3-diamine), 5d. Obtained in situ using BINAP ligand and 376 mg of tetraamine 1d. (MALDI-TOF) found: 501.41. C28H53N8 requires 501.44 [M+H]+. 1H NMR (CDCl3, 298 K) 5H ppm: 1.528-1.63 (8Н, m), 1.77 (4Н, quintet, 3J = 6.6 Hz), 2.55-2.70 (20Н, m), 3.19 (4Н, t, 3J = 6.4 Hz), 6.49-6.55 (4Н, m), 7.35 (2Н, d, 3J = 8.6 Hz). 13C NMR (CDCl3, 298 K) Sc ppm: 29.2 (2С), 30.2 (2С), 33.6 (2С), 40.2 (2С), 42.7 (2С), 477 (4С), 48.4 (4С), 102.8 (2С), 113.6 (2С), 121.1 (1С), 128.4 (2С), 136.9 (1С), 146.6 (2С).
Cyclic dimer 7d was synthesized from in situ obtained compound 5d. Eluent CH2Cl2/MeOH/NH3aq 100:25:5, yellow glassy compound. Yield 75 mg (22 %). (MALDI-TOF) found: 625.4662. C38H57N8 requires 625.4706 [M+H]+. 1H NMR (CDCl3, 298 K) SH ppm: 1.67 (4Н, quintet, 3J = 5.7 Hz), 1.74 (8Н, quintet, 3J = 6.3 Hz), 2.64-2.72 (16Н, m), 3.15 (8Н, t, 3J = 6.3 Hz), 4.14 (4Н, br.s), 6.52-6.56 (8Н, m), 7.38 (4Н, d, 3J = 9.1 Hz), NH protons of dialkylamino groups were not assigned. 13C NMR (CDCl3, 298 K) Sc ppm: 29.0 (6С), 42.7 (4С), 48.1 (4С), 48.9 (4С), 103.1 (4C),c 113.6 (4С), 121.2 (2С), 128.5 (4С), 137.0 (2С), 146.7 (4С). Macrocycle 6d was obtained as the side product. Eluent CH2Cl2/ MeOH/NH3aq 100:25:5. Yield 65 mg (19 %). Spectral data are given in ref.14 Cyclic trimer 10d (n = 2) was obtained as the side product. Eluent CH2Cl2/MeOH/NH3aq 10:4:1. Yield 80 mg (24 %), yellow glassy compound. (MALDI-TOF) found: 937.68. C57H85N12 requires 937.70 [M+H]+. 1H NMR (CDCl3, 298 K) SH ppm: 1.515-1.82 (18Н, m), 2.56-2.74 (24Н, m), 3.18 (12Н, t, 3J = 6.1 Hz), 4.24 (6Н, br.s), 6.52 (6Н, d, 3J = 8.5 Hz), 6.57 (6Н, br.s), 7.38 (6Н, d, 3J = 8.5 Hz), NH protons of dialkylamino groups were not assigned. 13C NMR (CDCl3, 298 K) 5c ppm: 29.2 (6С), 30.1 (2С), 42.7 (6С), 48.4 (12С), 102.9 (6С), 113.7 (6С), 128.5 (6С), 137.0 (3С), 146.7 (6С), three quaternary carbon atoms were not assigned.
Results and Discussion
Our synthetic aproach to the nitrogen- and oxygen-containing macrocycles based on 2,7-diaminonaphthalene is represented in Scheme 1. To synthesize the macrocycles 6 bearing the naphthalene fragment in the cycle, two successive Pd-catalyzed amination reactions of 2,7-dibromonaphtalene with a linear polyamine molecule should be carried out, which proceed in a one-pot manner when the synthesis of the macrocycles 6 is the synthetic goal (Scheme 1). The first amination reaction affords a linear intermediate compounds 3 whose intramolecular macrocyclization leads to the target compounds 6. The cyclization competes with the formation of linear compounds: N,N'-bis(7-bromonaphth-2-yl) substituted polyamines 4 and 2,7-bis(polyamine)
substituted naphthalenes 5. By changing catalytic system and reaction conditions, we have shown how to manage this process and achieve good yields of the macrocycles 6.[14] The best yields of the macrocycles were obtained when the starting compounds were reacted in the stoichiometric ratio. Interestingly, cyclodimers 7 were often isolated in notable yields under these conditions. These large macrocycles represent a new family of macrocyclic ligands and are of potential interest for supramolecular studies. Thus we focused on the development of the catalytic conditions for the synthesis of these large macrocycles. According to Scheme 1, target cyclodimers 7 can be formed from either intermediate 4 or intermediate 5, and herein we compare
these two synthetic approaches with the objective to find an optimal synthetic route to these ligands.
According to the first synthetic route, W,W-bis(7-bromonaphth-2-yl) substituted polyamines 4a-c were synthesized using the Pd-catalyzed reaction of 1 equiv. of di- and polyamines 1a-c with 2.2 equiv. of 2,7-dibromonaphthalene (2) (Scheme 2).
The reactivity of oxadiamines 1a,b and polyamine 1c was found to be significantly different. At first we carried out the cross-coupling reaction using a catalytic system Pd(dba)2/BINAP (BINAP = 2,2'-bis(diphenylphosphino)-1,1'-binaphthalene) which was found to be efficient in the synthesis of N,N'-bis(haloaryl) substituted di-
br
H,N
NH,
1a-c
Pd(dba)2/L NaOfBu dioxane, 100 °C
L = BINAP, Xantphos
Br Br
4a, 27%; 4b, 37%; 4c, 27%
Br Br
8a, 10%; 8b, 10%
Br
Scheme 2.
X1-
Br 4a-c
Br
h2n nh2
1a-c (1 equiv.) ->
Pd(dba)2/BINAP (8/9 mol%) NaOfBu dioxane, 100 °C
7a, 11 %;7b, 28%; 7c, 21 %; 7ab, 13 %
10b (n = 3, 5),11 ? 10c (n = 3), 11 %
Scheme 3.
Br H2N NH2 1a,b,d (4 equiv.)
Pdidbafe/L (4/4,5 mol%) NaOiBu, dioxane, 100 °C
HN., jl V
NH HN
^-x
7a, 10% 7 b, 30% 7rl OOOL
HoN
5a,b,d in situ
10a (n = 2,3), 21% 10b in = 2-4). 25%
2 (3 equiv.)
Pdfdbafe/BINAP (8/9 mol%) NaOfBu, dioxane, 100 °C
6b, 24%: 6d, 19%
Scheme 4.
and polyamines.[17] However, in the case of dioxa- and trioxadiamines 1a,b, side products like N,N-diarylated diamines 8a,b and linear oligomers 9a,b were predominant in the reaction mixtures, and the target compounds 4a,b could not be isolated in pure form. We changed BINAP for a less efficient ligand Xantphos (9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene) and diluted the reaction mixtures (0.05 M solutions instead of usual 0.1-0.2 M were used). As a result, we managed to isolate target diarylated oxadiamines 4a,b in moderate yields together with N,N,N'-triarylated amines 8a,b and more complex oligomers 9a,b resulting from the diamination reaction. The N,N'-diarylation of the tetraamine 1c should be conducted using BINAP as ligand because Xantphos was not efficient for this reaction. Under these conditions, the target product 4c and compound 9c were obtained as major products and were isolated in pure form by column chromatorgphy.
The N,N'-bis(bromonaphthyl) derivatives 4a-c were introduced in the Pd-catalyzed macrocyclization reaction with the same polyamines 1a-c (Scheme 3). In this case we applied 8 mol% of the catalytic system Pd(dba)2/BINAP, equimolar amounts of starting compounds and 0.02 M solutions of the reactants in dioxane. The best yield of the cyclodimers 7 was obtained for trioxadiamine derivative 7b (28 %), tetraamine 1c provided 21 % yield of the compound 7c, while the short dioxadiamine 1a gave a poor yield of
the corresponding cyclodimer 7a (11 %). The unsymmetric macrocycle 7a,b was obtained upon reacting compound 4b with dioxadiamine 1a. Cyclic tetramers and hexamers 10b,c were also isolated as by-products in these reactions.
An alternative method for the synthesis of cyclodimers included the formation of 2,7-bis(polyamine)substituted naphthalenes 5a,b,d which cannot be separated by the column chromatography in pure form and were used in situ (Scheme 4). The reactions were conducted using 4 equiv. of di- and polyamines 1a,b,d in dioxane (0.1 M solutions) in the presence of 4 mol% of the catalyst. As in the synthesis ofN,N'-bis(bromonaphthyl) substituted polyamines 4, Xantphos was applied in the reactions with dioxa- and trioxadiamines 1a,b and BINAP was used for tetraamine 1d. After NMR analysis proving that compounds 5a,b,d were the major products in the reaction mixtures, 3 equiv. of 2,7-dibromonaphthalene (2), 8 mol% of Pd(dba)/BINAP catalytic system, additional amounts of BONa and dioxane were added and the reaction mixtures were refluxed for 24 h. The best yield of the cyclodimer was obtained in the case of trioxadiamine (7b, 30 %), compound 7d was isolated in 22 % yield, while the product 7a containing two dioxadiamine chains again was obtained in a low yield (10 %). Cyclic oligomers of higher masses 10a,b,d were isolated in comparable yields 21-25 % in all cases, and also we observed the formation of the macrocycles comprising one naphthalene and one
A. D. Averin et al.
polyamine unit 6b,d. The latter compounds were formed at the second step of the process due to the presence of the excess of polyamines 1 in the reaction mixture which were not consumed at the first step.
Conclusions
To sum up, we investigated two alternative approaches for the synthesis of macrocycles comprising two naphthalene and two polyamine moieties (cyclodimers) based on the Pd-catalyzed amination reaction. The first one, including the synthesis of N,N'-bis(7-bromonaphth-2-yl) substituted polyamines, needs chromatographic isolation of these intermediate compounds due to the formation of by-products. The second route is a one-pot method with the formation of 2,7-bis(polyamine) substituted naphthalenes which are used in situ in the second macrocyclization step. Two synthetic routes were compared for different target cyclodimers. Optimization of experimental conditions are needed in both synthetic routes and the nature of the catalyst is a key factor influencing the product yields. The optimization of the one-pot reaction seems to be easier and better overall yields of the target cyclic dimers were obtained. Xantphos ligand was shown to be efficient for the synthesis of naphthalene linear derivatives with oxadiamines, while BINAP was found to be useful in the analogous reactions with tetraamine and in all macrocyclization reactions. Careful optimization of catalytic conditions allows to achieve the overall product yields up to 30 % without employing multistep methodologies.
Acknowledgements. This work was carried out in the frame of the International Associated French-Russian Laboratory of Macrocycle Systems and Related Materials (LAMREM) of the Centre National de la Recherche Scientifique (CNRS). It was financially supported by CNRS, RFBR grant 12-0393107, and by the Russian Academy of Sciences program
P-8 "Development of the methods for the synthesis of new chemicals and creation of new materials".
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Received 21.12.2012 Accepted 20.02.2013
