基于联萘酚骨架的新型圆偏振发光材料的合成及性能探究

doi:10.6023/A22030122

摘要/Abstract

合成了基于联萘酚骨架并具有电子给体二芳基胺(NN)、电子给受体二芳基胺和二芳基硼(BN)、电子给受体二芳基胺和氰基(4N2CN)的系列手性发光分子, 通过引入不同的受体基团和扩展分子的手性骨架来比较几个分子的性质差异. 由于分子内电荷转移(ICT)特性, 化合物BN和4N2CN表现出显著的温度响应型荧光发射位移. 二芳基硼的引入使得BN在常见有机溶剂中的荧光量子效率相比NN明显提高并表现出更显著的溶剂化变色效应. 为了探索它们的手性光学性质, 三个消旋体化合物在光学提纯后进行圆二色光谱(CD)和圆偏振发光光谱(CPL)测试. 因为化合物4N2CN手性骨架的扩展, 其CPL信号和发光不对称因子(g_lum)优于NN. 这项工作可能有助于开发新型手性发光材料, 也为增强分子激发态的手性信号提供了一种思路.

关键词: 联萘酚, 圆偏振发光, 热响应型发光, 聚集诱导发光, 电子给受体

A series of chiral luminescent molecules based on binaphthol skeleton and having electron donor diarylamine (NN), electron donor/acceptor diarylamine and diarylboron (BN), electron donor/acceptor diarylamine and cyano (4N2CN) were synthesized. The properties of several molecules were compared by introducing different acceptor groups and extended molecular chiral skeletons. Compounds BN and 4N2CN exhibit significant thermochromic shift of the emission due to the intramolecular charge transfer (ICT) character. The emission wavelength was linearly enhanced with a high correlation coefficient of 0.991 for BN between 345 K and 150 K, 0.996 for 4N2CN between 345 K and 180 K. Furthermore, a fully reversible emission response was corroborated by an excellent fatigue resistance without emission degradation upon its exposure to 5 cycles of temperature change over a range of 195 K and 165 K for BN and 4N2CN. Optical resolution of the racemic mixtures have been performed for further investigation. The initial injection of these molecules into a chiral high performance liquid chromatography (HPLC) with a Daicel Chiralpak IA column resulted in two separated peaks with 1∶1 area. We try to further explore their chiral optical properties, including circular dichroism (CD) and circular polarized luminescence (CPL). The signal of CD indicates their chiral properties in the ground state. However, the difference of CPL signals of these compounds shows that the difference of group and skeleton will affect the chiral properties of molecules in the excited state. BN showed high brightness and Φ_L of BN in solution can reach 0.99. In addition, 4N2CN exhibit aggregation-induced emission (AIE) properties in polar solvent and dynamic light scattering (DLS) was employed to monitor the process of aggregate formation. Based on this, we believe that the skeleton expansion and the introduction of electron-donor/acceptor groups make 4N2CN have unique photophysical properties. This work not only expands the family of chiral optical structures but also provides an idea to enhance the CPL signal and glum values.

Key words: binaphthol, circularly polarized luminescence, thermoresponsive emission, aggregation-induced emission, electron-donor/acceptor

引用此文

刘斌, 陈磅宽. 基于联萘酚骨架的新型圆偏振发光材料的合成及性能探究[J]. 化学学报, 2022, 80(7): 929-935.

Bin Liu, Pangkuan Chen. Synthesis and Properties of Novel Circularly Polarized Luminescence Materials Based on Binaphthol Skeleton[J]. Acta Chimica Sinica, 2022, 80(7): 929-935.

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图/表 9

图1. BN, NN和4N2CN的结构(以S构象展示)

Figure 1. Structures of BN, NN and 4N2CN (display in S configuration)

图2. BN,NN和4N2CN的合成路线

Figure 2. Synthetic route of BN, NN and 4N2CN Reagents and conditions: (i) CuCl(OH)·TMEDA, CH2Cl2, O2; (ii) CH2BrCl, K2CO3, DMF, 50 ℃; (iii) tetrafluoroterephthalonitrile, K2CO3, DMF, 50 ℃; (iv) bis(4-tert-butylphenyl)amine, Pd(OAc)2, t-BuONa, Xantphos, toluene, reflux; (v) n-BuLi, Mes2BF, THF, –78 ℃ to r.t.

图3. BN, NN and 4N2CN的紫外/可见吸收和发射图

Figure 3. UV/Vis absorption and emission spectra of BN, NN and 4N2CN UV/Vis absorption and emission spectra of NN (λex=390 nm), BN (λex=400 nm) and 4N2CN (λex=390 nm) (THF, c=1.0×10–5 mol/L). Inset: photograph showing the emission colors under the 365 nm UV lamp

	λ_abs^a/nm	λ_em^a/nm	Φ_L^b	Φ_S^c	τ_ave^d/ns
BN	400	534	0.90	0.16	2.5
NN	397	457	0.69	0.18	2.8
4N2CN	387	581	0.03	0.13	17

表1. BN, NN和4N2CN的光物理性质

Table 1. Photophysical properties of BN, NN and 4N2CN

图4. BN,NN和4N2CN的CV曲线(vs. Fc+/Fc)

Figure 4. Cyclic voltammogram (CV) curves (vs. Fc+/Fc) of BN, NN and 4N2CN Oxidation potentials diagrams of NN, BN and 4N2CN were recorded in CH2Cl2. Reduction potentials diagrams of 4N2CN and BN were recorded in THF vs. Fc/Fc+, using n-Bu4NPF6 (c=0.1 mol/L) as the electrolyte, v=100 mV/s

图5. 4N2CN的聚集诱导发光性质

Figure 5. Aggregation induced emission properties of 4N2CN (a) Emission spectra of 4N2CN in Water/DMF with increasing fw (c=1.0×10–5 mol/L, λex=390 nm) and photograph taken under 365 nm UV irradiation (inset); (b) dynamic Light Scattering (DLS) spectra of 4N2CN

图6. 4N2CN的热响应型发光性质

Figure 6. Thermoresponsive emission properties of 4N2CN (a) Temperature-dependent emission spectra of 4N2CN recorded in 2-methyltetrahydrofuran between 180 and 345 K (c=1.0×10–5 mol/L, λex=390 nm); (b) CIE color coordinates; (c) data fitting of the emission (λmax) dependence on T for 4N2CN, and (d) reversible emission modulation with cycling T changes for 4N2CN

图7. BN, NN和4N2CN的CPL信号

Figure 7. CPL signals of BN, NN and 4N2CN Smoothed CPL spectra of enantiomers for BN, NN and 4N2CN in toluene (a) and THF (b) (c=1.0×10–5 mol/L)

	g_lum of BN (×10^–4)	g_lum of NN (×10^–4)	g_lum of 4N2CN (×10^–3)
THF (+)	2.7	4.0	1.5
THF (–)	—	–2.9	–1.6
Toluene (+)	2.8	4.6	0.95
Toluene (–)	–1.0	–3.4	–0.84

表2. BN, NN和4N2CN在四氢呋喃和甲苯中的glum对比

Table 2. Comparison of glum of BN, NN and 4N2CN in THF and toluene

参考文献 24

[1]	(a) Mandal, P. K.; Collie, G. W.; Kauffmann, B.; Huc, I. Angew. Chem., Int. Ed. 2014, 53, 14424. doi: 10.1002/anie.201409014
	(b) Xiao, W.; Ernst, K. H.; Palotas, K.; Zhang, Y.; Bruyer, E.; Peng, L.; Greber, T.; Hofer, W. A.; Scott, L. T.; Fasel, R. Nat. Chem. 2016, 8, 326. doi: 10.1038/nchem.2449
	(c) Gonźalez-Rubio, G.; Liz-Marzán, L. M. Nature 2018, 556, 313. doi: 10.1038/d41586-018-04205-1
[2]	(a) Nakamura, K.; Furumi, S.; Takeuchi, M.; Shibuya, T.; Tanaka, K. J. Am. Chem. Soc. 2014, 136, 5555. doi: 10.1021/ja500841f pmid: 24670158
	(b) Cruz, C. M.; CastroFernández, S.; Maçôas, E.; Cuerva, J. M.; Campaña, A. G. Angew. Chem., Int. Ed. 2018, 57, 14782. doi: 10.1002/anie.201808178 pmid: 24670158
	(c) Han, X.-N.; Han, Y.; Chen, C.-F. J. Am. Chem. Soc. 2020, 142, 8262. doi: 10.1021/jacs.0c00624 pmid: 24670158
	(d) Li, M.; Lin, W.-B.; Fang, L.; Chen, C.-F. Acta Chim. Sinica 2017, 75, 1150. (in Chinese) doi: 10.6023/A17090440 pmid: 24670158
	(李猛, 林伟彬, 房蕾, 陈传峰, 化学学报, 2017, 75, 1150.) doi: 10.6023/A17090440 pmid: 24670158
	(e) Song, L.-F.; Zhou, Y.-Y.; Gao, T.; Yan, P.-F.; Li, H.-F. Acta Chim. Sinica 2021, 79, 1042. (in Chinese) doi: 10.6023/A21040185 pmid: 24670158
	(宋龙飞, 周妍妍, 高婷, 闫鹏飞, 李洪峰, 化学学报, 2021, 79, 1042.) doi: 10.6023/A21040185 pmid: 24670158
[3]	(a) Carr, R.; Evans, N. H.; Parker, D. Chem. Soc. Rev. 2012, 41, 7673. doi: 10.1039/c2cs35242g pmid: 29652488
	(b) Takaishi, K.; Yasui, M.; Ema, T. J. Am. Chem. Soc. 2018, 140, 5334. doi: 10.1021/jacs.8b01860 pmid: 29652488
	(c) Ma, J.-L.; Peng, Q.; Zhao, C.-H. Chem. - Eur. J. 2019, 25, 15441. doi: 10.1002/chem.201903252 pmid: 29652488
[4]	(a) Grell, M.; Oda, M.; Whitehead, K. S.; Asimakis, A.; Neher, D.; Bradley, D. D. C. Adv. Mater. 2001, 13, 577. doi: 10.1002/1521-4095(200104)13:8＜577::AID-ADMA577＞3.0.CO;2-K
	(b) Li, M.; Li, S.-H.; Zhang, D.; Cai, M.; Duan, L.; Fung, M.-K.; Chen, C.-F. Angew. Chem., Int. Ed. 2018, 57, 2889. doi: 10.1002/anie.201800198
	(c) Zinna, F.; Voci, S.; Arrico, L.; Brun, E.; Homberg, A.; Bouffier, L.; Funaioli, T.; Lacour, J.; Sojic, N.; Di Bari, L. Angew. Chem., Int. Ed. 2019, 58, 6952. doi: 10.1002/anie.201901303
	(d) Liang, Z.-P.; Tang, R.; Qiu, Y.-C.; Wang, Y.; Lu, H.-B.; Wu, Z.-G. Acta Chim. Sinica 2021, 79, 1401. (in Chinese) doi: 10.6023/A21070355
	(梁志鹏, 唐瑞, 邱雨晨, 王阳, 陆洪彬, 吴正光, 化学学报, 2021, 79, 1401.) doi: 10.6023/A21070355
[5]	(a) Zinna, F.; Giovanella, U.; Bari, L. D. Adv. Mater. 2015, 27, 1791. doi: 10.1002/adma.201404891
	(b) Brandt, J. R.; Salerno, F.; Fuchter, M. J. Nat. Rev. Chem. 2017, 1, 0045. doi: 10.1038/s41570-017-0045
	(c) Song, F.; Xu, Z.; Zhang, Q.; Zhao, Z.; Zhang, H.; Zhao, W.; Qiu, Z.; Qi, C.; Zhang, H.; Sung, H. H. Y.; Williams, I. D.; Lam, J. W. Y.; Zhao, Z.; Qin, A.; Ma, D.; Tang, B. Z. Adv. Funct. Mater. 2018, 28, 1800051. doi: 10.1002/adfm.201800051
[6]	(a) Tang, Y.; Cohen, A. E. Science 2011, 332, 333. doi: 10.1126/science.1202817
	(b) Takaishi, K.; Yamamoto, T.; Hinoide, S.; Ema, T. Chem. - Eur. J. 2017, 23, 9249. doi: 10.1002/chem.201702143
	(c) He, C.; Yang, G.; Kuai, Y.; Shan, S.; Yang, L.; Hu, J.; Zhang, D.; Zhang, Q.; Zou, G. Nat. Commun. 2018, 9, 5117. doi: 10.1038/s41467-018-07533-y
[7]	(a) Takaishi, K.; Hinoide, S.; Matsumoto, T.; Ema, T. J. Am. Chem. Soc. 2019, 141, 11852. doi: 10.1021/jacs.9b06240 pmid: 31184485
	(b) Jiang, Q.; Xu, X.; Yin, P.-A.; Ma, K.; Zhen, Y.; Duan, P.; Peng, Q.; Chen, W.-Q.; Ding, B. J. Am. Chem. Soc. 2019, 141, 9490. doi: 10.1021/jacs.9b03305 pmid: 31184485
	(c) Zhang, C.; Yan, Z.-P.; Dong, X.-Y.; Han, Z.; Li, S.; Fu, T.; Zhu, Y.-Y.; Zheng, Y.-X.; Niu, Y.-Y.; Zang, S.-Q. Adv. Mater. 2020, 32, 2002914. doi: 10.1002/adma.202002914 pmid: 31184485
[8]	(a) Han, J.; Duan, P.; Li, X.; Liu, M. J. Am. Chem. Soc. 2017, 139, 9783. doi: 10.1021/jacs.7b04611
	(b) Liang, X.; Liu, T.-T.; Yan, Z.-P.; Zhou, Y.; Su, J.; Luo, X.-F.; Wu, Z.-G.; Wang, Y.; Zheng, Y.-X.; Zuo, J.-L. Angew. Chem., Int. Ed. 2019, 58, 17220. doi: 10.1002/anie.201909076
	(c) Zhao, W.-L.; Li, M.; Lu, H.-Y.; Chen, C.-F. Chem. Commun. 2019, 55, 13793. doi: 10.1039/C9CC06861A
[9]	(a) Sanchez-Carnerero, E. M.; Moreno, F.; Maroto, B. L.; Agarrabeitia, A. R.; Ortiz, M. J.; Vo, B. G.; Muller, G.; de la Moya, S. J. Am. Chem. Soc. 2014, 136, 3346. doi: 10.1021/ja412294s
	(b) Kumar, J.; Tsumatori, H.; Yuasa, J.; Kawai, T.; Nakashima, T. Angew. Chem., Int. Ed. 2015, 54, 5943. doi: 10.1002/anie.201500292
	(c) Takaishi, K.; Yamamoto, T.; Hinoide, S.; Ema, T. Chem. - Eur. J. 2017, 23, 9249. doi: 10.1002/chem.201702143
[10]	(a) Field, J. E.; Muller, G.; Riehl, J. P.; Venkataraman, D. J. Am. Chem. Soc. 2003, 125, 11808. doi: 10.1021/ja035626e pmid: 22335235
	(b) Sawada, Y.; Furumi, S.; Takai, A.; Takeuchi, M.; Noguchi, K.; Tanaka, K. J. Am. Chem. Soc. 2012, 134, 4080. doi: 10.1021/ja300278e pmid: 22335235
	(c) Katayama, T.; Nakatsuka, S.; Hirai, H.; Yasuda, N.; Kumar, J.; Kawai, T.; Hatakeyama, T. J. Am. Chem. Soc. 2016, 138, 5210. doi: 10.1021/jacs.6b01674 pmid: 22335235
	(d) Otani, T.; Tsuyuki, A.; Iwachi, T.; Someya, S.; Tateno, K.; Kawai, H.; Saito, T.; Kanyiva, K. S.; Shibata, T. Angew. Chem., Int. Ed. 2017, 56, 3906. doi: 10.1002/anie.201700507 pmid: 22335235
	(e) Qiu, Z.; Ju, C.-W.; Frédéric, L.; Hu, Y.; Schollmeyer, D.; Pieters, G.; Müllen, K.; Narita, A. J. Am. Chem. Soc. 2021, 143, 4661. doi: 10.1021/jacs.0c13197 pmid: 22335235
[11]	(a) Morisaki, Y.; Gon, M.; Sasamori, T.; Tokitoh, N.; Chujo, Y. J. Am. Chem. Soc. 2014, 136, 3350. doi: 10.1021/ja412197j
	(b) Gon, M.; Morisaki, Y.; Chujo, Y. J. Mater. Chem. C 2015, 3, 521. doi: 10.1039/C4TC02339K
	(c) Chen, J.-F.; Yin, X.; Wang, B.; Zhang, K.; Meng, G.; Zhang, S.; Shi, Y.; Wang, N.; Wang, S.; Chen, P. Angew. Chem., Int. Ed. 2020, 59, 11267. doi: 10.1002/anie.202001145
[12]	(a) Lee, S.; Kaib, P. S. J.; List, B. J. Am. Chem. Soc. 2017, 139, 2156. doi: 10.1021/jacs.6b11993 pmid: 30950265
	(b) Takaishi, K.; Hinoide, S.; Matsumoto, T.; Ema, T. J. Am. Chem. Soc. 2019, 141, 11852. doi: 10.1021/jacs.9b06240 pmid: 30950265
	(c) Takaishi, K.; Iwachido, K.; Takehana, R.; Uchiyama, M.; Ema, T. J. Am. Chem. Soc. 2019, 141, 6185. doi: 10.1021/jacs.9b02582 pmid: 30950265
[13]	Kimoto, T.; Tajima, N.; Fujiki, M.; Imai, Y. Chem. Asian J. 2012, 7, 2836. doi: 10.1002/asia.201200725
[14]	(a) Tsumatori, H.; Nakashima, T.; Kawai, T. Org. Lett. 2010, 12, 2362. doi: 10.1021/ol100701w pmid: 20405955
	(b) Zhang, S.; Wang, Y.; Meng, F.; Dai, C.; Cheng, Y.; Zhu, C. Chem. Commun. 2015, 51, 9014. doi: 10.1039/C5CC01994J pmid: 20405955
	(c) Zhang, K.; Zhao, J. Y.; Zhang, N.; Chen, J. F.; Wang, N.; Yin, X. D.; Zheng, X. Y.; Chen, P. K. J. Mater. Chem. C 2022, 10, 1816. doi: 10.1039/D1TC05329A pmid: 20405955
[15]	(a) Entwistle, C. D.; Marder, T. B. Angew. Chem., Int. Ed. 2002, 41, 2927. doi: 10.1002/1521-3773(20020816)41:16＜2927::AID-ANIE2927＞3.0.CO;2-L
	(b) Zhou, G.; Ho, C.-L.; Wong, W.-Y.; Wang, Q.; Ma, D.; Wang, L.; Lin, Z.; Marder, T. B.; Beeby, A. Adv. Funct. Mater. 2008, 18, 499. doi: 10.1002/adfm.200700719
	(c) Sun, Z.-B.; Liu, J.-K.; Yuan, D.-F.; Zhao, Z.-H.; Zhu, X.-Z.; Liu, D.-H.; Peng, Q.; Zhao, C.-H. Angew. Chem., Int. Ed. 2019, 58, 4840. doi: 10.1002/anie.201813320
	(d) Chen, J.-F.; Yin, X.; Zhang, K.; Zhao, Z.; Zhang, S.; Zhang, N.; Wang, N.; Chen, P. J. Org. Chem. 2021, 86, 12654. doi: 10.1021/acs.joc.1c01175
	(e) Xia, Z.-Q.; Shao, A.-D.; Li, Q.; Zhu, S.-Q.; Zhu, W.-H. Acta Chim. Sinica 2016, 74, 351. (in Chinese) doi: 10.6023/A16010001
	(夏志清, 邵安东, 李强, 朱世琴, 朱为宏, 化学学报, 2016, 74, 351.) doi: 10.6023/A16010001
	(f) Wang, T.; Hua, X.; Yu, Y.; Yuan, Y.; Feng, M.; Jiang, Z. Chin. J. Org. Chem. 2019, 39, 1436. (in Chinese) doi: 10.6023/cjoc201810016
	(王彤彤, 华晓晨, 郁友军, 袁熠, 冯敏强, 蒋佐权, 有机化学, 2019, 39, 1436.) doi: 10.6023/cjoc201810016
	(g) Yu, J.; Xiao, Y.; Chen, J. Chin. J. Org. Chem. 2019, 39, 3460. (in Chinese) doi: 10.6023/cjoc201906019
	(俞佳, 肖雅方, 陈嘉雄, 有机化学, 2019, 39, 3460.) doi: 10.6023/cjoc201906019
[16]	(a) Zhao, W.; Zhuang, X.; Wu, D.; Zhang, F.; Gehrig, D.; Laquai, F.; Feng, X. J. Mater. Chem. A 2013, 1, 13878. doi: 10.1039/c3ta13334f
	(b) Sudhakar, P.; Mukherjee, S.; Thilagar, P. Organometallics 2013, 32, 3129. doi: 10.1021/om301197f
[17]	(a) Liu, Z.-Q.; Shi, M.; Li, F.-Y.; Fang, Q.; Chen, Z.-H.; Yi, T.; Huang, C.-H. Org. Lett. 2005, 7, 5481. doi: 10.1021/ol052323b
	(b) Stahl, R.; Lambert, C.; Kaiser, C.; Wortmann, R.; Jakober, R. Chem. - Eur. J. 2006, 12, 2358. doi: 10.1002/chem.200500948
[18]	(a) Yuan, Z.; Entwistle, C. D.; Collings, J. C.; Albesa-Jové, D.; Batsanov, A. S.; Howard, J. A. K.; Taylor, N. J.; Kaiser, H. M.; Kaufmann, D. E.; Poon, S.-Y.; Wong, W.-Y.; Jardin, C.; Fathallah, S.; Boucekkine, A.; Halet, J.-F.; Marder, T. B. Chem. - Eur. J. 2006, 12, 2758. doi: 10.1002/chem.200501096
	(b) Cao, D.; Liu, Z.; Fang, Q.; Xu, G.; Xue, G.; Liu, G.; Yu, W. J. Organomet. Chem. 2004, 689, 2201. doi: 10.1016/j.jorganchem.2004.04.006
	(c) Liu, Z.; Fang, Q.; Wang, D.; Cao, D.; Xue, G.; Yu, W.; Lei, H. Chem. - Eur. J. 2003, 9, 5074. doi: 10.1002/chem.200304833
[19]	(a) Shirota, Y.; Kinoshita, M.; Noda, T.; Okumoto, K.; Ohara, T. J. Am. Chem. Soc. 2000, 122, 11021. doi: 10.1021/ja0023332
	(b) Doi, H.; Kinoshita, M.; Okumoto, K.; Shirota, Y. Chem. Mater. 2003, 15, 1080. doi: 10.1021/cm020948n
	(c) Hudson, Z. M.; Sun, C.; Helander, M. G.; Amarne, H.; Lu, Z. H.; Wang, S. Adv. Funct. Mater. 2010, 20, 3426. doi: 10.1002/adfm.201000904
[20]	(a) Duan, L.; Qiao, J.; Sun, Y.; Qiu, Y. Adv. Mater. 2011, 23, 1137. doi: 10.1002/adma.201003816
	(b) Zhang, D.; Song, X.; Gillett, A. J.; Drummond, B. H.; Jones, S. T. E.; Li, G.; He, H.; Cai, M.; Credgington, D.; Duan, L. Adv. Mater. 2020, 32, 1908355. doi: 10.1002/adma.201908355
[21]	MacLean, M. W.; Wood, T. K.; Wu, G.; Lemieux, R. P.; Crudden, C. M. Chem. Mater. 2014, 26, 5852. doi: 10.1021/cm501826b
[22]	Zang, E.-S.; Hou, X.-F.; Zang, Z.; Zhang, Y.-Q.; Wang, J.-J.; Yang, H.; You, J.-M.; Ju, P. J. Mater. Chem. C 2019, 7, 8404. doi: 10.1039/C9TC01725A
[23]	(a) Hong, Y.; Lam, J. W. Y.; Tang, B. Z. Chem. Soc. Rev. 2011, 40, 5361. doi: 10.1039/c1cs15113d
	(b) Zhang, Y.; Li, D.; Li, Y.; Yu, J. Chem. Sci. 2014, 5, 2710. doi: 10.1039/c4sc00721b
	(c) Gu, Y.; Zhao, Z.; Su, H.; Zhang, P.; Liu, J.; Niu, G.; Li, S.; Wang, Z.; Kwok, R. T. K.; Ni, X.-L.; Sun, J.; Qin, A.; Lam, J. W. Y.; Tang, B. Z. Chem. Sci. 2018, 9, 6497. doi: 10.1039/C8SC01635F
	(d) Zhao, Z.; Zhang, H.; Lam, J. W. Y.; Tang, B. Z. Angew. Chem., Int. Ed. 2020, 59, 9888. doi: 10.1002/anie.201916729
[24]	Zhang, Z.; Edkins, R. M.; Nitsch, J.; Fucke, K.; Steffen, A.; Longobardi, L. E.; Stephan, D. W.; Lambert, C.; Marder, T. B. Chem. Sci. 2015, 6, 308. doi: 10.1039/C4SC02410A