All the reagents and solvents were purchased from commercial sources and were used without further purification, unless otherwise mentioned. Thin-layer chromatography (TLC) analysis was carried out on silica gel plates and imaged under ultraviolet light. Column chromatography was performed using silica gel 60 N (spherical, neutral) 63–210 μm. Nuclear magnetic resonance (NMR) spectra were recorded by 400 MHz for 1H NMR and 100 MHz for 13C NMR spectrometer, chemical shifts (δ) were determined in parts per million (ppm) relative to TMS (δ = 0.00 ppm), coupling constants (J) in Hz. Data are reported as follows: chemical shift, multiplicity (s = singlet, d = doublet, dd = doublet of doublets, t = triplet, q = quartet, and m = multiplet), coupling constant (Hz), and integration IR spectra were recorded with a Jasco FT/IR 6600 spectrometer. UV–vis spectra were measured with a SHIMADZU UV-3600 Plus spectrophotometer. Fluorescence emission spectra were performed using a FluoroMax-4 spectrofluorometer. Mass spectra were performed with a Mass Spectrometric Thermo Fisher Scientific LTQ Orbitrap XL by the Natural science center for basic research and development (N-BARD), Hiroshima University.

1-(2-nitro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethan-1-ol (8): To a solution of 1-(5-bromo-2-nitrophenyl)ethan-1-ol (100 mg, 0.41 mmol), 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane) ( 144.8 mg, 0.57 mmol), PdCl2(dppf)2 (30 mg, 0.041 mmol), potassium acetate (80.5 mg, 0.82 mmol) in dioxane (1.5 mL) in a round-bottom flask and was degassed under N2. Then the reaction mixture was stirred at 80 \(^\circ\) for 15 h. After evaporation of dioxane, the residue was extracted with EtOAc, washed with water, dried over Na2SO4 and evaporated under reduced pressure. The crude was purified using column chromatography to obtain compound 8 (52.9 mg, 44%). 1H NMR (400 MHz, CDCl3) δ 8.22 (s, 1 H), 7.80 (s, 2 H), 5.38–5.33 (m, 1 H), 2.58 (s, 1H), 1.58 (d, J = 6.4 Hz, 3 H) 1.34 (s, 12 H). 13C NMR (100 MHz, CDCl3) δ 149.8, 139.6, 134.4, 134.1, 123.2, 84.7, 65.7, 25.0, 24.9, 24.4. IR (KBr, cm−1): 3514, 2978, 1525, 1346, 1141,1103, 963, 914, 879, 765, 710, 623. HRMS-ESI calcd m/z: for C14H20O5NBNa [M + Na]+ 316.1329, found 316.1331.

1-(5-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-nitrophenyl)ethan-1-ol (1): A solution of 4-(5-bromothiophen-2-yl)-N,N-dimethylaniline 7 [50] (25 mg, 0.089 mmol), 8 ( 31.2 mg, 0.106 mmol) in 2.0 mL Toluene:EtOH:H2O (3:1:1) and degassed under N2 for 30 min. Then K2CO3 (24.6 mg, 0.18 mmol), Pd(PPh3)4 (10.3 mg, 8.9 \(\times\) 10–3 mmol) were added into mixture and degassed again under N2 for 30 min. The reaction mixture was stirred at 60 \(^\circ\) for 15 h. After evaporation of dioxane, the residue was extracted with EtOAc, washed with water, dried over Na2SO4 and evaporated under reduced pressure. The crude was purified using column chromatography to obtain compound 1 (24 mg, 73%). 1H NMR (400 MHz, CDCl3) δ 8.06 (d, J = 2.08 Hz, 1 H), 8.01 (d, J = 8.56 Hz, 1 H), 7.61–7.58 (d, J = 8.64 and 2.12 Hz, 1 H), 7.54–7.52 (m, 2 H), 7.45 (d, J = 3.88 Hz, 1 H), 7.19 (d, J = 3.88 Hz, 1 H), 6.75–6.73 (m, 2 H), 5.59–5.53 (m, 1 H), 3.01 (s, 6 H), 1.63–1.62 (d, J = 4.0 Hz, 1 H). 13C NMR (100 MHz, CDCl3) δ 150.6, 148.1, 145.4, 142.7, 140.4, 138.4, 127.0, 126.9, 125.9, 124.1, 123.6, 122.3, 112.6, 66.1, 40.5, 24.4. IR (KBr, cm−1): 3322, 2979, 1878, 1758, 601, 1511, 1331, 1174, 1110, 1083, 990, 705, 536. HRMS-ESI calcd for C20H21O3N2S [M + H]+ 369.1267, found 369.1269. mp: 157–159\(^\circ\).

1-(5-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-nitrophenyl)ethyl benzoate (3): Compound 1-(5-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-nitrophenyl)ethan-1-ol 1 (15 mg, 0.04 mmol) and benzoic acid (5.3 mg, 0.044 mmol), 4-dimethylaminopyridine (DMAP) (0.5 mg, 10%mol) in dichloromethane (DCM, 1.6 mL) was stirred for 10 min. Then N, N'-dicyclohexylcarbodiimide (DCC) (9.1 mg, 0.044 mmol), was added and stirred for 23 h at room temperature. The reaction mixture was extracted with DCM, washed with H2O, dried over Na2SO4. Flash chromatography on silica gel afforded compound 3 (14.3 mg, 75%). 1H NMR (400 MHz, CDCl3) δ 8.12 (m, 2 H), 8.05 (d, J = 8.64 Hz, 1 H), 7.92 (d, J = 2.1 Hz, 1 H) 7.61–7.57 (m, 2 H), 7.50–7.46 (m, 4 H), 7.35 (d, J = 2.1 Hz, 1 H), 7.15 (d, J = 2.1 Hz, 1 H), 6.73–6.69 (m, 3 H), 3.01 (s, 6 H), 1.83 (d, J = 6.5 Hz, 3 H). 13C NMR (100 MHz, CDCl3) δ 165.6, 150.6, 148.1, 145.4, 140.4, 139.7, 138.2, 133.4, 130.2, 129.8, 128.7, 126.9, 126.8, 126.0, 124.5, 123.2, 122.3, 122.0, 112.5, 69.1, 40.5, 22.3. IR (KBr, cm−1): 3426, 2925, 1602, 1580, 1485, 1327, 1274, 1109, 1076, 807, 719, 538. HRMS-ESI calcd for C27H24O4N2S [M]+ 472.1451, found 472.1451.

1-(2-nitro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethan-1-ol (9): To a solution of 1-(4-bromo-2-nitrophenyl)ethan-1-ol [51] (40 mg, 0.163 mmol), 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane) (49.5 mg, 0.195 mmol), PdCl2(dppf)2 (13.2 mg, 0.1%mol) and potassium acetate (71.5 mg, 0.728 mmol) in dioxane (1.5 mL) in a round-bottom flask and was degassed under N2. Then the reaction mixture was stirred at 80 \(^\circ\) for 15 h. After evaporation of dioxane, the residue was extracted with EtOAc, washed with water, dried over Na2SO4 and evaporated under reduced pressure. The crude was purified using column chromatography to obtain compound 9 (31.3 mg, 65.6%). 1H NMR (400 MHz, CDCl3) δ 8.28 (s, 1 H), 8.03 (d, J = 7.8 Hz, 1 H), 7.82 (d, J = 7.8 Hz, 1 H), 5.44–5.39 (m, 1 H), 1.56 (d, J = 6.3 Hz, 3 H), 1.35 (s, 12 H). 13C NMR (100 MHz, CDCl3) δ 147.7, 143.6, 139.6, 130.4, 127.0, 84.7, 65.7, 25.0, 24.9, 24.4. IR (KBr, cm−1): 3436, 2980, 2931, 1342, 1619, 1529, 1364, 1272, 1144, 1097, 964, 908, 672. HRMS-ESI calcd for C14H20O5N3BNa [M + Na]+ 316.1329, found 316.1327.

1-(4-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-nitrophenyl)ethan-1-ol (2): A solution of 4-(5-bromothiophen-2-yl)-N,N-dimethylaniline 7 [50] (24.1 mg, 0.08 mmol), 1-(2-nitro-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)ethan-1-ol 9 (30.1 mg, 0.1 mmol) in 2.0 mL Toluene:EtOH:H2O (3:1:1) and degassed under N2 for 30 min. Then K2CO3 (23.7 mg, 0.16 mmol), Pd(PPh3)4 (10.3 mg, 10% mol) were added into the reaction mixture and degassed again under N2 for 30 min. The reaction mixture was stirred at 60 \(^\circ\) for overnight. After evaporation of dioxane, the residue was extracted with EtOAc, washed with water, dried over Na2SO4 and evaporated under reduced pressure. The crude was purified using silica gel column chromatography to obtain compound 2 (20.5 mg, 70%). 1H NMR (400 MHz, CDCl3) δ 8.10 (d, J = 1.4 Hz, 1 H), 7.83–7.82 (m, 2 H), 7.53–7.49 (m, 2 H), 7.34(d, J = 3.8 Hz, 1 H), 7.15 (d, J = 3.8 Hz, 1 H) 6.75–6.73 (m, 2H), 5.44–5.39 (m, 1 H), 3.01 (s, 6 H), 1.60 (d, 3 H). 13C NMR (100 MHz, CDCl3) δ 150.5, 148.4, 146.7, 138.8, 137.9, 135.3, 130.0, 128.3, 126.92, 125.7, 122.2, 122.1, 120.6, 112.6, 65.7, 40.6, 24.3. IR (KBr, cm−1): 3397, 2369, 2351, 1610, 1574, 1474, 1445, 1260, 1233, 1085, 1070, 903, 869, 830, 797, 606, 594, 514. HRMS-ESI calcd for C20H21O3N2S [M \(+\) H]+ 369.1267, found 369.1268.

1-(4-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-nitrophenyl)ethyl benzoate (4): Compound 1-(4-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-nitrophenyl)ethan-1-ol 2 (20.5 mg, 0.056 mmol) and benzoic acid (7.2 mg, 0.06 mmol), DMAP (0.7 mg, 10%mol) in DCM (2.2 mL) was stirred for 10 min. To the reaction mixture, DCC (12.4 mg, 0.06 mmol) was added and stirred for 23 h at room temperature. The reaction mixture was extracted with DCM, washed with H2O, dried over Na2SO4. Flash chromatography on silica gel afforded compound 4 (19.8 mg, 75%). 1H NMR (400 MHz, CDCl3) δ 8.16 (d, J = 1.88 Hz, 1 H), 8.09–8.07 (m, 2 H), 7.81–7.78 (dd, J = 8.24 and 1.84 Hz, 1 H), 7.70 (d, J = 8.28 Hz, 1 H), 7.60–7.56 (m, 1 H), 7.51–7.44 (m, 4 H), 7.32 (d, J = 3.8 Hz, 1 H), 7.14 (d, J = 3.8 Hz, 1 H), 6.74–6.72 (m, 2 H), 6.59–6.54 (m, 1 H), 3.00 (s, 6 H), 1.81 (d, J = 6.48 Hz, 3 H). 13C NMR (100 MHz, CDCl3) δ 165.6, 150.5, 148.4, 146.9, 137.8, 135.9, 135.6, 133.4, 130.1, 130.0, 129.8, 128.6, 127.9, 126.9, 125.8, 122.15, 122.05, 120.8, 68.9, 40.5, 22.2. IR (KBr, cm−1): 3423, 2342, 1717, 1530, 1356, 1270, 1173, 1102, 955, 888, 540. HRMS-ESI calcd for C27H24O4N2SNa [M + Na]+ 495.1349, found 495.1349.

Diethyl 3, 12-bis(2-ethoxy-2-oxoethyl)-5-(2-nitro-5-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl)-6,9-dioxa-3,12-diazatetradecanedioate (10): chelator EGTA [47] (111.9 mg, 0.172 mmol), 4,4,4',4',5,5,5',5'-octamethyl-2,2'-bi(1,3,2-dioxaborolane) (61.2 mg, 0.241 mmol), PdCl2(dppf)2 (12.6 mg, 0.017 mmol), potassium acetate ( 47.3 mg, 0.482 mmol) were mixed in 1.6 mL dioxane in a round-bottom flask and degassed under N2 for 30 min. Then, the reaction mixture was stirred for 15 h at 80 \(^\circ\). The reaction mixture was filtered, the filtrate was extracted with EtOAc, washed with H2O. The organic layer was dried over Na2SO4 and removed the solvent under reduced pressure. The residue was purified by silica gel column chromatography to give the desired product 10 (42%). 1H-NMR of compound 10 (400 MHz, CDCl3): \(\updelta\) 8.09 (s, 1 H), 7.84–7.78 (m, 2 H), 5.13–5.10 (dd, J = 8 and 4 Hz, 1 H), 4.17–4.08 (m, 8 H), 3.78–3.67 (m, 4 H), 3.56–3.41 (m, 10 H), 3.02–2.90 (m, 4 H), 1.34 (s, 12 H), 1.27–1.20 (m, 12 H). 13C NMR (100 MHz, CDCl3) δ 171.9, 171.5, 150.5, 135.2, 135.0, 134.7, 123.3, 84.6, 70.2, 68.9, 61.4, 60.5, 56.0, 55.8, 53.8, 25.0, 25.0, 14.4. IR (KBr, cm−1): 3625, 3484, 2359, 1514, 808, 761, 722, 702, 630, 503. HRMS-ESI calcd for C34H54O14N3BNa [M + Na]+ 762.3591, found 762.3607.

5-(5-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-nitrophenyl)-3,12-bis(2-ethoxy-2-oxoethyl)-6,9-dioxa-3,12 diazatetradecanedioate (5): compound 10 (105.5 mg, 0.14 mmol), compound 7 [50] (79.5 mg, 0.28 mol) dissolved in Toluene (0.25 mL) and EtOH (0.25 mL) were degassed under N2 for 30 min. To a solution of Pd(PPh3)4 (16.2 mg, 10 mol%), potassium carbonate (58 mg, 0.42 mmol) in H2O (1.25 mL) were added and degassed under N2 again for 30 min. The solution was heated to 60 \(^\circ\) for 15 h. The reaction mixture was filtered, the filtrate was extracted with EtOAc, washed with H2O. The organic layer was dried over Na2SO4 and removed the solvent under reduced pressure. The residue was purified by silica gel column chromatography to give the desired product 5 (46%). 1H-NMR of compound 5 (400 MHz, CDCl3): δ 8.04 (d, J = 8.6 Hz, 1 H), 8.01 (d, J = 1.88 Hz, 1 H), 7.59–7.50 (m, 3 H), 7.47 (d, J = 3.9 Hz, 1 H), 7.23 (d, J = 4 Hz, 1 H), 6.74 (d, J = 8.9 Hz, 2 H), 5.33–5.30 (m, 1 H), 4.19–4.07 (m, 8 H), 3.79 (s, 4 H), 3.61–3.48 (m, 10 H), 3.19–2.3.06 (m, 2 H), 3.01 (m, 6 H), 2.95–2.90 (m, 2 H), 1.29–1.19 (m, 12 H). 13C NMR (100 MHz, CDCl3) δ 171.9, 171.5, 150.6, 148.1, 146.0, 140.2, 138.4, 127.2, 127.0, 126.1, 124.5, 124.2, 122.3, 122.1, 112.5, 70.4, 69.1, 61.5, 60.5, 56.0, 55.8, 53.9, 40.5, 14.4, 14.4. IR (KBr, cm−1): 3441, 2931, 2343, 1735, 1510, 1335, 1199, 758. HRMS-ESI calcd for C40H54O12N4NaS [M + Na]+ 837.3351, found 837.3347.

3, 12-bis(carboxymethyl)-5-(5-(5-(4-(dimethylamino)phenyl)thiophen-2-yl)-2-nitrophenyl)6,9-dioxa-3,12-diazatetradecanedioic acid (6): To a solution of compound 5 (59 mg, 0.072 mmol) in methanol (6 mL), then KOH (22 mg, 0.4 mmol) was added to hydrolyzed. The reaction mixture was stirred at 60 \(^\circ\) for 7 h. After evaporation of the solvent, the reaction mixture was acidified with 1N HCl to pH 1. The reaction mixture was evaporated and dissolved with methanol. The yellow organic layer was taken and evaporated to afford 6 (100%). 1H NMR (400 MHz, CD3OD) δ 8.23 (d, J = 8 Hz, 1 H), 8.14 (d, J = 4 Hz, 1 H), 7.6 (d, J = 8 Hz, 3 H), 7.77- 7.75 (m, 3 H), 7.67 (d, J = 4 Hz, 1 H), 5.68 (d, J = 8 Hz, 1 H), 4.53 (s, 4 H), 4.25 (m, 4 H), 4.00–3.60 (m, 10 H), 3.33 (s, 6 H). 13C NMR (100 MHz, CD3OD) δ 168.4, 168.2, 148.0, 145.5, 143.4, 142.7, 141.2, 136.7, 135.1, 129.6, 128.8, 128.1, 127.9, 127.8, 126.3, 122.9, 74.4, 71.4, 69.6, 66.9, 60.9, 57.5, 56.7, 30.6. IR (KBr, cm−1): 3403, 2365, 2341, 1638, 1405, 549, 514. HRMS-ESI calcd for C32H38O12N4NaS [M + Na]+ 725.2099, found 725.2102.