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研究生:劉威群
研究生(外文):Wei-Chun Liu
論文名稱:硼烷基取代氮異環碳烯:合成與反應機構探討
論文名稱(外文):Borylated N-Heterocyclic Carbenes:Synthesis and Mechanism Studies
指導教授:邱靜雯
口試日期:2017-06-28
學位類別:碩士
校院名稱:國立臺灣大學
系所名稱:化學研究所
學門:自然科學學門
學類:化學學類
論文種類:學術論文
論文出版年:2017
畢業學年度:105
語文別:英文
論文頁數:100
中文關鍵詞:硼取代基咪唑鹽氮異環碳烯自由基分子位移
外文關鍵詞:Boryl imidazolium saltN-heterocyclic carbeneradicalmigration
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氮異環碳烯對於過渡金屬甚至是主族元素一直是相當重要的配基,為了要更加廣泛研究氮異環碳烯及其錯合物的應用性,許多種不同推電子基團修飾的碳烯分子已經被報導,並應用在催化反應上。然而,具有拉電子基團的氮異環碳烯研究,卻比較少被探討。為了要了解拉電子的硼取代基對於氮異環碳烯的影響,我們合成一系列、在1號位有不同硼烷基取代的咪唑鹽,並嘗試其碳烯的合成。有趣的是,當我們嘗試要進行去質子化的過程當中,我們觀察到硼烷基的1,2-位移的現象,進而產生2-硼烷取代咪唑。為了研究此1,2-位移反應的反應機構,我們設計了一系列的實驗。在交錯實驗中,我們證明此1,2-位移反應是一個分子間的重組過程;在自由基捕捉實驗中顯示,在去質子化的過程中會有硼-氮斷鍵的發生,並生成兩個自由基。搭配上交錯實驗的結果,推測這兩個自由基分子應有一定的穩定度,可以脫離溶劑作用進行分子間重組。最後,我們也根據一系列的研究結果搭配理論計算,推測出一個較為完善的、可能的反應機構。
N-Heterocyclic Carbenes (NHCs) have been regarded as promising supporting ligands for their great bonding ability toward transition metal and main group element. To broaden chemistry of NHCs and NHC complexes, several electron-donating functional groups have been incorporated into the imidazole ring. Electron-withdrawing group, however, received considerable less attention. In an attempt to realize the N-borylated N-heterocyclic carbene, a series of N-borylated imidazolium salts have been prepared and characterized. Interestingly, the deprotonation of the N-boryl imidazolium salt initiated a 1,2-boryl shift from nitrogen atom to the C2 carbon of imidazole to yield the corresponding 2-boryl imidazole. In order to understand the migration process, we have carried out the crossover experiment, which confirmed the inter-molecular migration processes upon deprotonation. Also, radical trapping experiments revealed the presence of two unusual radical species, a Li+ coordinated NHC radical and a diarylboryl radical, originated from homolytic B-N bond breaking. Therefore, the 1,2-boryl migration of NHC can be explained. Upon generation of the putative N-boryl NHC, a B-N bond cleavage occurred to generate two stable radicals, which could escape the solvent cage and recombine randomly to accomplish the intermolecular migration process.
致謝 i
摘要 ii
Abstract iii
Contents iv
List of figures vi
List of schemes viii
List of tables x
Chapter 1. Introduction 1
1.1 N-Heterocyclic carbenes 1
1.1.1 Properties of N-Heterocyclic carbenes 1
1.1.2 History of N-Heterocyclic carbenes 4
1.1.3 Applications of NHCs and NHC metal complexes 6
1.1.4 Modifications of N-Heterocyclic carbenes 8
1.2 Radical species 12
1.2.1 Aminyl radicals 12
1.2.2 Boron radicals 14
1.3 Migration of molecules 17
Chapter 2. Research objectives and results 22
2.1 Synthesis and characterizations 23
2.1.1 N-tert-butyl, N’-dimesitylboryl imidazole adduct (1-Aa) 23
2.1.2 N-tert-butyl, N’-dimesitylboryl imidazolium triflate [2-Aa][OTf] 24
2.1.3 1,2-Boryl migration of [2-Aa][OTf] upon deprotonation. 25
2.2 Evaluation on thermostabilities of N-boryl NHC and 2-boryl imidazole 28
Chapter 3. Migration mechanism studies 30
3.1 Crossover experiment 30
3.1.1 Appropriate crossover substrates 32
3.1.2 Crossover experiment 35
3.2 Trapping experiments with transition metal complexes 39
3.2.1 NHC trapping experiment with Me2SAuCl 40
3.2.2 NHC trapping experiment with [Ir(cod)Cl]2 40
3.3 Trapping experiments with radical scavengers 42
3.3.1 Trapping reaction with DMPO 42
3.3.2 Radical trapping reaction with different alkali amide 47
3.4 Proposed mechanism 49
Chapter 4. Conclusion 51
References 53
Chapter 5. Experimental section 56
1.Wanzlick, H. W.; Schikora, E., Angew. Chem. Int. Ed. 1960, 72 (14), 494-494.
2.Wanzlick, H. W.; Schikora, E., Chem. Ber. 1961, 94 (9), 2389-2393.
3.Wanzlick, H. W.; Schönherr, H. J., Angew. Chem. Int. Ed. 1968, 7 (2), 141-142.
4.Öfele, K., J. Organomet. Chem. 1968, 12 (3), 42-43.
5.Arduengo, A. J.; Harlow, R. L.; Kline, M., J. Am. Chem. Soc. 1991, 113 (1), 361-363.
6.Egbert, J. D.; Cazin, C. S. J.; Nolan, S. P., Catal. Sci. Tech. 2013, 3 (4), 912-926.
7.Farrell, J. M.; Hatnean, J. A.; Stephan, D. W., J. Am. Chem. Soc. 2012, 134 (38), 15728-15731.
8.Huang, J.; Schanz, H.-J.; Stevens, E. D.; Nolan, S. P., Organometallics 1999, 18 (12), 2370-2375.
9.Clavier, H.; Nolan, S. P., Chem. Commun. 2010, 46 (6), 841-861.
10.Martin, D.; Lassauque, N.; Donnadieu, B.; Bertrand, G., Angew. Chem. Int. Ed. 2012, 51 (25), 6172-6175.
11.Wacker, A.; Pritzkow, H.; Siebert, W., Eur. J. Inorg. Chem. 1998, 1998 (6), 843-849.
12.Fisher, S. P.; El-Hellani, A.; Tham, F. S.; Lavallo, V., Dalton Trans. 2016, 45 (24), 9762-9765.
13.Hildebrandt, B.; Raub, S.; Frank, W.; Ganter, C., Chem. Eur. J. 2012, 18 (21), 6670-6678.
14.Buhl, H.; Ganter, C., Chem. Commun. 2013, 49 (47), 5417-5419.
15.Schwedtmann, K.; Schoemaker, R.; Hennersdorf, F.; Bauza, A.; Frontera, A.; Weiss, R.; Weigand, J. J., Dalton Trans. 2016, 45 (28), 11384-11396.
16.Ruamps, M.; Lugan, N.; César, V., Organometallics 2017, 36 (5), 1049-1055.
17.Wieland, H., Berichte der deutschen chemischen Gesellschaft 1911, 44 (3), 2550-2556.
18.Gumrukcu, I.; Hudson, A.; Lappert, M. F.; Slade, M. J.; Power, P. P., Chem. Commun. 1980, 16, 776-777.
19.Pitts, J. N.; Finlayson, B. J., Angew. Chem. Int. Ed. 1975, 14 (1), 1-15.
20.Eymann, L. Y. M.; Tskhovrebov, A. G.; Sienkiewicz, A.; Bila, J. L.; Živković, I.; Rønnow, H. M.; Wodrich, M. D.; Vannay, L.; Corminboeuf, C.; Pattison, P.; Solari, E.; Scopelliti, R.; Severin, K., J. Am. Chem. Soc. 2016, 138 (46), 15126-15129.
21.Negoita, N.; Baican, R.; Balaban, A. T., Tetrahedron Lett. 1973, 14 (21), 1877-1878.
22.Neugebauer, F. A.; Fischer, H., Chem. Ber. 1972, 105 (8), 2686-2693.
23.Chu, T. L.; Weismann, T. J., J. Am. Chem. Soc. 1956, 78 (1), 23-26.
24.Leffler, J. E.; Watts, G. B.; Tanigaki, T.; Dolan, E.; Miller, D. S., J. Am. Chem. Soc. 1970, 92 (23), 6825-6830.
25.Olmstead, M. M.; Power, P. P., J. Am. Chem. Soc. 1986, 108 (14), 4235-4236.
26.Chiu, C.-W.; Gabbaï, F. P., Angew. Chem. Int. Ed. 2007, 46 (10), 1723-1725.
27.Matsumoto, T.; Gabbaï, F. P., Organometallics 2009, 28 (15), 4252-4253.
28.Dahcheh, F.; Martin, D.; Stephan, D. W.; Bertrand, G., Angew. Chem. Int. Ed. 2014, 53 (48), 13159-13163.
29.Wood, T. K.; Piers, W. E.; Keay, B. A.; Parvez, M., Chem. Commun. 2009, 34, 5147-5149.
30.Köster, R.; Benedikt, G.; Schrötter, H. W., Angew. Chem. Int. Ed. 1964, 76 (14), 649-650.
31.New Books. J. Phys. Chem. A 1899, 4 (8), 690-693.
32.Meerwein, H., Justus Liebigs Annalen der Chemie 1914, 405 (2), 129-175.
33.Wang, Z., John Wiley & Sons, Inc.: 2010.
34.Sabrina Kronig; M. Sc. Eileen Theuergarten; Constantin G. Daniliuc; Peter G. Jones; Matthias Tamm; Angew. Chem. Int. Ed. 2012, 52, 3240-3244
35.Chen, M.; Wang, Y.; Gilliard, R. J.; Jr; Wei, P.; Schwartz, N. A.; Robinson, G. H., Dalton Trans. 2014, 43 (38), 14211-14214.
36.Marchenko, A. P.; Koidan, H. N.; Zarudnitskii, E. V.; Hurieva, A. N.; Kirilchuk, A. A.; Yurchenko, A. A.; Biffis, A.; Kostyuk, A. N., Organometallics 2012, 31 (23), 8257-8264.
37.Marchenko, A. P.; Koidan, H. N.; Pervak, I. I.; Huryeva, A. N.; Zarudnitskii, E. V.; Tolmachev, A. A.; Kostyuk, A. N., Tetrahedron Lett. 2012, 53 (5), 494-496.
38.Winkler, A.; Freytag, M.; Jones, P. G.; Tamm, M., J. Organomet. Chem. 2015, 775, 164-168.
39.Winkler, A.; Freytag, M.; Jones, P. G.; Tamm, M., Z. Anorg. Allg. Chem. 2016, 642 (22), 1295-1303.
40.Keating, A. E.; Garcia-Garibay, M. A.; Houk, K. N., J. Am. Chem. Soc. 1997, 119 (44), 10805-10809.
41.Solé, S.; Gornitzka, H.; Guerret, O.; Bertrand, G., J. Am. Chem. Soc. 1998, 120 (35), 9100-9101.
42. Xavier, C.; Karinne, M.; Heinz, G.; Didier, B.; Bertrand, G., J. Am. Chem. Soc. 2005, 127 (42), 3292-3293.
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