1

New Journal of Chemistry

Supplementary Information for:

Porphyrin–boron diketonate dyads

Letícia D. Costa, Samuel Guieu, João Rocha, Artur M. S. Silva and Augusto C. Tomé

Content Supplementary Information for: ................................................................................... 1

General.............................................................................................................................. 2

Synthesis ........................................................................................................................... 2

Precursor derivatives 1, Zn1 and 2 ............................................................................... 2

2,2-Difluoro-4,6-dimethyl-2H-1λ3,3,2λ4-dioxaborinine, 7........................................... 2

2,2-Difluoro-4,6-di-p-tolyl-2H-1λ3,3,2λ4-dioxaborinine, 8 .......................................... 3

2-(2,4-Dioxopentan-3-yl)-5,10,15,20-tetraphenylporphyrin (enolic form), 2 .............. 3

2-(2,4-Dioxopentan-3-yl)-5,10,15,20-tetraphenylporphyrinatozinc(II) (enolic form),

Zn2 ................................................................................................................................ 3

2-(1,3-Dioxo-1,3-di-p-tolylpropan-2-yl)-5,10,15,20-tetraphenylporphyrin (diketone

form), 3 ......................................................................................................................... 4

2-(1,3-Dioxo-1,3-di-p-tolylpropan-2-yl)-5,10,15,20-tetraphenylporphyrinatozinc(II)

(diketone form), Zn3..................................................................................................... 5

2-(2,2-Difluoro-4,6-dimethyl-2H-1λ3,3,2λ4-dioxaborinin-5-yl)-5,10,15,20-

tetraphenylporphyrin, 4 ................................................................................................ 5

2-(2,2-Difluoro-4,6-dimethyl-2H-1λ3,3,2λ4-dioxaborinin-5-yl)-5,10,15,20-

tetraphenylporphyrinatozinc(II), Zn4 ........................................................................... 6

7-(2,2-difluoro-4,6-di-p-tolyl-2H-1λ3,3,2λ4-dioxaborinin-5-yl)-5,10,15,20-

tetraphenylporphyrin, 5 ................................................................................................ 6

2-(2,2-Difluoro-4,6-di-p-tolyl-2H-1λ3,3,2λ4-dioxaborinin-5-yl)-5,10,15,20-

tetraphenylporphyrinatozinc(II), Zn5 ........................................................................... 7

2-[2-Oxo-2-(p-tolyl)ethyl]-5,10,15,20-tetraphenylporphyrin, 6................................... 8

NMR spectra ..................................................................................................................... 9

References ...................................................................................................................... 23

Electronic Supplementary Material (ESI) for New Journal of Chemistry.This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2017

2

General

With the exception of toluene, dried over sodium wire, all reagents were used as

supplied. Analytical TLC was carried out on precoated sheets with silica gel (Merck 60, 0.2

mm thick). All compounds were purified by column chromatography on silica gel (Merck, 35–70 mesh) or by preparative TLC carried out on 20 cm × 20 cm glass plates, coated with silica gel (0.5 mm thick).

1H, 13C and 19F NMR spectra were recorded on Bruker Avance 300 and 500 spectrometers at 300.13/500.13, 75.47/126.76 and 282.38 MHz, respectively. CDCl3 was used as the solvent and tetramethylsilane (TMS) as the internal standard. Chemical shifts δ are reported in parts per million (ppm) relative to TMS (δ = 0), and the values of coupling constants (J) are given in Hertz (Hz). Unequivocal 1H assignments were made using 2D COSY (1H−1H), while 13C assignments were made on the basis of 2D HSQC (1H−13C) and HMBC (delay for long-range J C−H couplings) experiments.

High resolution mass spectra analysis (HRMS-ESI+) were performed on a microTOF (focus) mass spectrometer. Ions were generated using an Apollo II (ESI) source. Ionization was achieved by electrospray, using a voltage of 4500 V applied to the needle, and a counter voltage between 100 and 150 V applied to the capillary.

The UV-Vis spectra in toluene solutions were obtained on a Shimadzu UV-2501 PC spectrophotometer (1 cm path length quartz cell). The excitation and emission spectra, also in toluene solutions, were recorded with a Jobin Yvon FluoroMax-3 spectrofluorometer. Fluorescence quantum yields φF were determined using 5,10,15,20-tetraphenylporphyrin (TPP) in toluene (φF = 0.11) as a fluorescence standard. The fluorescence quantum yields were calculated by comparing the area below the corrected emission spectrum with that of TPP, by applying the method described in the literature.

Synthesis

Precursor derivatives 1, Zn1 and 2 The 2-nitro-5,10,15,20-tetraphenylporphyrin (1),1 the corresponding zinc

complex (Zn1), the 2-(2,4-dioxopentan-3-yl)-5,10,15,20-tetraphenylporphyrin (2),2 and 1,3-di-p-tolylpropane-1,3-dione3 were synthesized following procedures described in the literature, and properly characterized by 1H NMR.

2,2-Difluoro-4,6-dimethyl-2H-1λ3,3,2λ4-dioxaborinine, 7 Prepared following a reported procedure.4 To a solution of pentane-2,4-dione (51 µL, 0.5 mmol) in dry CH2Cl2 were added K2CO3 (69 mg, 0.5 mmol,) and BF3·OEt2 (61 µL, 0.5 mmol). After stirring at room temperature for 30 min, water was added and the product was extracted with CH2Cl2. The

3

organic phases were collected, dried over Na2SO4, and concentrated under reduced pressure to afford compound 7 as an off-white oily solid (74 mg, quant.). 1H NMR (300 MHz, CDCl3): δ = 5.97 (s, 1H, C-H), 2.30 (s, 6H, CH3) ppm. 13C NMR (75.47 MHz, CDCl3): δ = 192.6 (C=O), 102.1, 24.3 ppm. 19F NMR (282 MHz, CDCl3) δ = -161.41 ppm.

2,2-Difluoro-4,6-di-p-tolyl-2H-1λ3,3,2λ4-dioxaborinine, 8

Prepared following a reported procedure.5 To a solution of 1,3-di-p-tolylpropane-1,3-dione (126 mg, 0.5 mmol) in dry toluene was added BF3·OEt2 (67 µL, 0.55 mmol). After stirring at reflux for 1 h, the reaction mixture was cooled down to room temperature and a

solid crystallized. The solid was collected by filtration, washed with hexane and dried in air. The product was obtained as a bright yellow solid (130 mg, 87% yield). 1H NMR (300 MHz, CDCl3): δ = 8.05 (d, 3JH-H 8.2 Hz, 4H, C-H), 7.35 (d, 3JH-H 8.2 Hz, 4H, C-H), 7.13 (s, 1H, C-H), 2.48 (s, 6H, CH3) ppm. 13C NMR (75.47 MHz, CDCl3): δ = 182.7 (C=O), 146.8, 130.1, 129.5, 129.1, 92.8, 22.1 ppm. 19F NMR (282 MHz, CDCl3): δ = -163.28 ppm.

2-(2,4-Dioxopentan-3-yl)-5,10,15,20-tetraphenylporphyrin (enolic form), 2 Prepared following a reported procedure.6

1H NMR (300 MHz, CDCl3): δ = 16.42 (s, 1H, OH), 8.88-8.81 (m, 4H, H-β), 8.78 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.66 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.65 (s, 1H, H-3), 8.25-8.16 (m, 6H, Ho), 7.95 (dd, 3JH-H 7.8, 4JH-H 1.5 Hz, 2H, Ho), 7.84-7.71 (m, 9H, 8×Hm + Hp), 7.69-7.57 (m, 3H, Hp), 1.86 (s, 6H, 2×CH3), -2.68 (s, 2H, NH) ppm. 13C NMR (126 MHz, CDCl3): δ 194.90 (C=O), 144.01, 142.34, 142.09, 142.00, 141.94, 135.08, 134.77, 134.70, 133.73, 133.57, 129.23, 129.08, 128.56, 127.91, 127.88, 127.67, 126.90, 126.81, 120.58, 120.51, 120.46, 118.80, 58.66, 21.74 (CH3) ppm. ESI+-MS m/z (%) = 713.29 (100) [M + H]+

HRMS-ESI+ m/z for C49H37N4O2 calcd 713.29165, found 713.29068. UV–Vis (toluene) (log ε): 420 (5.74), 515 (4.37), 549 (3.90), 592 (3.77), 648 (3.50) nm.

2-(2,4-Dioxopentan-3-yl)-5,10,15,20-tetraphenylporphyrinatozinc(II) (enolic form), Zn2

To a solution of Zn1 (25 mg, 0.035 mmol) in DMSO (1.5 mL), pentane-2,4-dione (36 μL, 0.35 mmol) and K2CO3 (35 mg, 0.274 mmol) were added. The reaction mixture was stirred at 60 °C under N2 atmosphere for 1 h. After cooling to room temperature, the reaction mixture was diluted with CH2Cl2 (10

mL), (washed with distilled water) and extracted with CH2Cl2. The organic phases were

4

collected, dried over Na2SO4, and concentrated under reduced pressure. After purification by flash column chromatography (silica gel) using toluene as eluent, the product was obtained as a dark pink solid (24.7 mg, 92% yield). 1H NMR (500 MHz, CDCl3): δ = 16.26 (s, 1H, OH), 8.96 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.95 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.93 (br s, 2H, H-β), 8.87 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.75 (s, 1H, H-3), 8.75 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.25-8.17 (m, 6H, Ho), 7.98-7.90 (m, dd, 3JH-H 8.2, 4JH-H 1.5 Hz, 2H, Ho), 7.81-7.70 (m, 9H, 8×Hm + Hp), 7.66 (tt, 3JH-H 7.6, 4JH-H 1.4 Hz, 1H, Hp), 7.60 (br tt, 3JH-H 7.0, 4JH-H 1.4 Hz, 2H, Hp), 1.81 (s, 6H, 2×CH3) ppm. 13C NMR (126 MHz, CDCl3): δ 190.20 (C=O), 151.23, 150.71, 150.58, 150.43, 150.36, 148.39, 147.00, 142.88, 142.76, 142.74, 142.23, 140.56, 136.63, 134.66, 134.57, 134.53, 132.63, 132.49, 132.35, 132.27, 132.20, 131.85, 128.11, 127.77, 127.73, 126.93, 126.77, 126.74, 121.82, 121.46, 121.11, 120.68, 112.06, 25.11 (CH3) ppm. ESI+-MS m/z (%) = 774.20 (100) [M]+

HRMS-ESI+ m/z for C49H34N4O2Zn calcd 774.19732, found 774.19609. UV-Vis (toluene) (log ε): 424 (5.65), 550 (4.23), 589 (3.33) nm.

2-(1,3-Dioxo-1,3-di-p-tolylpropan-2-yl)-5,10,15,20-tetraphenylporphyrin (diketone form), 3

To a stirring solution of Zn3 (42 mg, 0.045 mmol) in dry toluene (3 mL) was added, dropwise, BF3·OEt2 (10 syringe drops). The resulting green mixture was stirred at 80 °C for 24 h. After cooling to room temperature, the solvents were removed under reduced pressure. The residue thus obtained was dissolved in CH2Cl2, neutralized with a saturated solution of NaHCO3, washed with water and the organic layer dried

over Na2SO4. After purification by flash column chromatography (silica gel) using a 2:1 mixture of CH2Cl2/hexane as eluent, the free-base porphyrin 3 was obtained as a purple solid (34.5 mg, 87% yield). Two other minor products were also isolated: 5 (1.8 mg, 4% yield) and 6 (1.4 mg, 4% yield). 1H NMR (300 MHz, CDCl3): δ = 8.85 (d, 3JH-H 4.9 Hz, 1H, H-β), 8.83 (d, 3JH-H 4.9 Hz, 1H, H-β), 8.80-8.72 (m, 4H, H-3 + 3×H-β), 8.56 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.25-8.19 (m, 4H, 4×Ho), 8.16 (dd, 3JH-H 7.6, 4JH-H 1.6 Hz, 2H, 2×Ho), 8.10 (dd, 3JH-H 7.8, 4JH-H 1.5 Hz, 2H, 2×Ho), 7.79-7.67 (m, 9H, 8×Hm + Hp), 7.64 (d, 3JH-H 8.1 Hz, 4H, H-Ar), 7.39-7.30 (m, 3H, 3×Hp), 7.06 (d, 3JH-H 8.1 Hz, 4H, H-Ar), 6.88 (s, 1H, C-H), 2.30 (s, 6H, 2×CH3), -2.68 (s, 2H, NH) ppm. 13C NMR (126 MHz, CDCl3): δ 190.43 (C=O), 142.43, 142.21, 141.91, 141.35, 134.78, 134.76, 134.66, 132.46, 131.6, 131.4, 131.0, 130.8, 130.6, 129.2, 129.1, 128.35, 128.00, 127.96, 127.10, 126.95, 126.87, 126.85, 120.76, 120.53, 120.00, 119.93, 111.38, 58.7, 25.12 (CH3) ppm. ESI+-MS m/z (%) = 865.35 (100) [M + H]+

HRMS-ESI+ m/z for C61H45N4O2 calcd 865.35425, found 865.35281. UV-Vis (toluene) (log ε): 421 (5.70), 516 (4.30), 550 (3.82), 592 (3.71), 649 (3.45) nm.

5

2-(1,3-Dioxo-1,3-di-p-tolylpropan-2-yl)-5,10,15,20-tetraphenylporphyrinatozinc(II) (diketone form), Zn3

To a solution of Zn1 (33 mg, 0.045 mmol) in DMSO (2 mL) were added 1,3-di-p-tolylpropane-1,3-dione (11.4 mg, 0.45 mmol) and K2CO3 (5 mg, 0.36 mmol). The reaction mixture was stirred at 60 °C under N2 atmosphere for 26 h. After cooling down to room temperature, the reaction mixture was diluted with CH2Cl2, water was added, and extracted with

CH2Cl2. The organic phases were collected, dried over Na2SO4, and concentrated under reduced pressure. After purification by flash column chromatography (silica gel) using a 2:1 mixture of CH2Cl2/hexane as eluent, compound Zn3 was obtained as a purple solid (29.8 mg, 71% yield). 1H NMR (500 MHz, CDCl3): δ = 8.92 (s, 2H, H-β), 8.91 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.8 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.86 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.83 (s, 1H, H-3), 8.63 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.25-8.18 (m, 4H, 4×Ho), 8.14 (dd, 3JH-H 6.4, 4JH-H 2.9 Hz, 2H, 2×Ho), 8.06 (dd, 3JH-H 7.8, 4JH-H 1.5 Hz, 2H, 2×Ho), 7.78-7.61 (m, 13H), 7.35-7.30 (m, 3H, 2×Hm + Hp), 7.09 (d, 3JH-H 8.2 Hz, 4H, H-Ar), 6.90 (s, 1H, C-H), 2.32 (s, 6H, 2×CH3) ppm. 13C NMR (126 MHz, CDCl3): δ 195.42 (C=O), 151.12, 150.61, 150.60, 150.46, 150.16, 148.50, 145.95, 143.93, 142.92, 142.88, 142.83, 142.54, 137.30, 136.42, 134.89, 134.58, 134.55, 133.91, 133.26, 132.45, 132.29, 132.26, 132.18, 131.66, 129.22, 129.13, 128.38, 127.64, 127.47, 126.68, 121.61, 121.37, 121.22, 119.94, 59.15, 21.76 (CH3) ppm. ESI+-MS m/z (%) = 926.26 (100) [M]+

HRMS-ESI+ m/z for C61H42N4O2Zn calcd 926.25992, found 926.26036. UV-Vis (toluene) (log ε): 425 (5.80), 551 (4.37), 589 (3.51) nm.

2-(2,2-Difluoro-4,6-dimethyl-2H-1λ3,3,2λ4-dioxaborinin-5-yl)-5,10,15,20-tetraphenylporphyrin, 4

To a solution of 2-(1-acetyl-2-oxopropyl)-5,10,15,20-tetraphenylporphyrin 2 (14 mg, 0.02 mmol) in dry toluene (2 mL) K2CO3 (5.5 mg, 0.04 mmol) and BF3·OEt2 (5 µL, 0.04 mmol) were added, and the resulting solution immediately acquired a green colour. The mixture was stirred at 60 °C during 12 h. After cooling to room temperature, the solvent was removed

under reduced pressure. The residue was neutralized with a saturated aqueous solution of NaHCO3 and the product was extracted with CH2Cl2. The organic phases were collected, dried over Na2SO4, and concentrated under reduced pressure. After purification by flash column chromatography (silica gel) using a 2:1 mixture of CH2Cl2/hexane as eluent, compound 4 was obtained as a purple solid (13.1 mg, 88% yield). 1H NMR (300 MHz, CDCl3): δ = 8.90 (br s, 2H, H-β), 8.86-8.80 (m, 3H, H-β), 8.73 (d, 3JH-H 4.9 Hz, 1H, H-β), 8.64 (s, 1H, H-3), 8.25-8.17 (m, 6H, Ho), 7.95 (dd, 3JH-H 8.2, 4JH-H 1.4 Hz, 2H, Ho), 7.84-7.73 (m, 10H, 6×Hm + 4×Hp), 7.65 (t, 3JH-H 7.5 Hz, 2H, Hm), 2.10 (s, 6H, 2×CH3), -2.69 (s, 2H, NH) ppm.

6

13C NMR (75 MHz, CDCl3): δ = 190.3 (C=O), 142.02, 141.97, 141.7, 140.8, 137.2, 135.4, 134.74, 134.72, 134.67, 132.9, 132.7, 132.2, 130.9, 130.7, 130.5, 130.3, 129.8, 128.3, 128.1, 127.5, 127.0, 126.9, 121.0, 120.9, 120.5, 119.6, 112.7, 24.9 (CH3) ppm. 19F NMR (282 MHz, CDCl3) δ = -154.28 (d, 2JF-F 77.9 Hz, 1F), -159.85 (d, 2JF-F 77.9 Hz, 1F). ESI+-MS m/z (%) = 761.29 (100) [M + H]+

HRMS-ESI+ m/z for C49H36BF2N4O2 calcd 761.28994, found 761.28921. UV-Vis (toluene) (log ε): 421 (5.73), 516 (4.30), 550 (3.84), 593 (3.71), 649 (3.55) nm.

2-(2,2-Difluoro-4,6-dimethyl-2H-1λ3,3,2λ4-dioxaborinin-5-yl)-5,10,15,20-tetraphenylporphyrinatozinc(II), Zn4

To a solution of 4 (22 mg, 0.03 mmol) in chloroform (4 mL) was added zinc acetate di-hydrate (32 mg, 0.14 mmol) in methanol (1 mL). The mixture was heated at 60 °C for 1 h. The mixture was then washed with water and extracted with CH2Cl2. The organic phases were collected, dried over Na2SO4,

and concentrated under reduced pressure. After purification by flash column chromatography (silica gel) using a 2:1 mixture of CH2Cl2/hexane as eluent, compound Zn4 was obtained as a dark pink solid (21.6 mg, 91% yield). 1H NMR (300 MHz, CDCl3): δ = 8.97 (br s, 2H, H-β), 8.95 (br s, 2H, H-β), 8.91 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.79 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.78 (s, 1H, H-3), 8.23-8.18 (m, 6H, Ho), 7.94 (dd, 3JH-H 8.2, 4JH-H 1.4 Hz, 2H, Ho), 7.82-7.71 (m, 10H, 6×Hm + 4×Hp), 7.64 (t, 3JH-H 7.5 Hz, 2H, Hm), 2.10 (s, 6H, 2×CH3) ppm. 13C NMR (126 MHz, CDCl3): δ = 190.2 (C=O), 151.1, 151.03, 150.96, 150.4, 147.8, 145.5, 142.54, 142.51, 142.48, 141.7, 136.8, 135.7, 134.60, 134.56, 134.53, 132.8, 132.73, 132.70, 132.67, 132.6, 132.2, 132.0, 129.6, 128.0, 127.9, 127.3, 126.9, 126.8, 122.0, 121.8, 121.3, 120.7, 113.2, 25.0 (CH3) ppm. 19F NMR (282 MHz, CDCl3) δ = -154.07 (d, 2JF-F 78.2 Hz, 1F), -159.93 (d, 2JF-F 78.2 Hz, 1F). ESI+-MS m/z (%) = 822.20 (100) [M]+

HRMS-ESI+ m/z for C49H33BF2N4O2Zn calcd 822.19561, found 822.19459. UV-Vis (toluene) (log ε): 425 (5.71), 551 (4.28), 589 (3.51) nm.

7-(2,2-difluoro-4,6-di-p-tolyl-2H-1λ3,3,2λ4-dioxaborinin-5-yl)-5,10,15,20-tetraphenylporphyrin, 5

To a stirring solution of 2-(1-(p-tolyl)methanone-2-oxo-2-(p-tolyl)ethyl)-5,10,15,20-tetraphenylporphyrin 3 (34 mg, 0.04 mmol) in dry toluene (3 mL) BF3·OEt2 (39 µL, 0.2 mmol) was added. The resulting green mixture was stirred at 80 °C for 24 h. After cooling, the solvent was removed under reduced pressure. The residue obtained was then neutralized with a saturated solution of NaHCO3, washed with water and

extracted with CH2Cl2. The organic phase was collected and dried over Na2SO4. The product 5 was isolated as a purple solid (18.3 mg, 50% yield) after purification by flash column chromatography (silica gel) using a 2:1 mixture of CH2Cl2/hexane as eluent. The by-product 6 was also isolated (14.3 mg, 48% yield).

7

1H NMR (300 MHz, CDCl3): δ = 8.90 (s, 2H, H-β), 8.85 (d, 3JH-H 4.9 Hz, 1H, H-β), 8.81 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.72 (d, 3JH-H 4.9 Hz, 1H, H-β), 8.60 (s, 1H, H-3), 8.49(d, 3JH-H 4.9 Hz, 1H, H-β), 8.23 (dd, 3JH-H 7.3, 4JH-H 2.1 Hz, 2H, Ho), 8.17 (dd, 3JH-H 7.7, 4JH-H 1.6 Hz, 2H, Ho), 7.96-7.90 (m, 2H, Ho), 7.84-7.64 (m, 9H, 8×Hm + Hp), 7.65-7.53 (m, 2H, Hp), 7.48-7.46 (m, 3H, 2×Ho + Hp), 7.36 (d, 3JH-H 8.5 Hz, 4H, H-Ar), 6.51 (d, 3JH-H 8.3 Hz, 4H, H-Ar), 1.96 (s, 6H, 2×CH3), -2.63 (s, 2H, NH) ppm. 13C NMR (126 MHz, CDCl3): δ 182.14 (C=O), 143.87, 142.04, 141.94, 141.74, 140.64, 139.78, 134.98, 134.90, 134.76, 134.57, 133.49, 132.82, 132.01, 131.51, 131.1, 130.9, 130.3, 129.80, 129.58, 128.55, 128.13, 128.08, 128.05, 127.04, 126.98, 126.88, 126.82, 126.67, 120.85, 120.60, 120.49, 110.20, 21.43 (CH3) ppm. ESI+-MS m/z (%) = 913.35 (100) [M + H]+

HRMS-ESI+ m/z for C61H44BF2N4O2 calcd 913.35254, found 913.35191.

UV-Vis (toluene) (log ε): 424 (5.30), 519 (4.06), 554 (3.54), 596 (3.46), 652 (3.34) nm.

2-(2,2-Difluoro-4,6-di-p-tolyl-2H-1λ3,3,2λ4-dioxaborinin-5-yl)-5,10,15,20-tetraphenylporphyrinatozinc(II), Zn5

To a stirred solution of 5 (18 mg, 0.02 mmol) in chloroform (4 mL) was added zinc acetate di-hydrate (22 mg, 0.1 mmol) in methanol (1 mL). This mixture was heated at 80 °C for 2 h. After cooling to room temperature, water was added and the product was extracted CH2Cl2. The organic phase was collected, dried over Na2SO4, and concentrated under

reduced pressure. After purification by flash column chromatography (silica gel) using a 1:1 mixture of CH2Cl2/hexane as eluent, compound Zn5 was obtained as a dark pink solid (15.3 mg, 78% yield). 1H NMR (500 MHz, CDCl3): δ = 9.01 (br s, 2H, H-β), 8.95 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.93 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.81 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.76 (s, 1H, H-3), 8.56 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.23 (dd, 3JH-H 7.7, 4JH-H 1.4 Hz, 2H, Ho), 8.17 (dd, 3JH-H 7.5, 4JH-H 1.6 Hz, 2H, Ho), 7.95 (dd, 3JH-H 7.8, 4JH-H 1.3 Hz, 2H, Ho), 7.83-7.67 (m, 8H, 4×Hm + 4×Hp), 7.60 (m, 2H, Hm), 7.47-7.41 (m, 4H, 2×Ho + 2×Hm), 7.32 (d, 3JH-H 8.5 Hz, 4H, H-Ar), 6.48 (d, 3JH-H 8.5 Hz, 4H, H-Ar), 1.94 (s, 6H, 2×CH3) ppm. 13C NMR (126 MHz, CDCl3): δ = 181.9 (C=O), 151.5, 151.2, 151.0, 150.8, 150.1, 147.9, 145.7, 143.7, 142.6, 142.5, 142.3, 140.7, 139.0, 137.4, 134.7, 134.6, 134.4, 133.1, 132.76, 132.68, 132.6, 132.2, 131.7, 131.6, 129.4, 128.5, 127.9, 127.8, 126.9, 126.79, 126.77, 121.9, 121.60, 121.55, 121.45, 110.7, 21.4 (CH3) ppm. 19F NMR (282 MHz, CDCl3): δ = -155.60 (d, 2JF-F 80.2 Hz, 1F), -160.52 (d, 2JF-F 80.2 Hz, 1F) ppm.

ESI+-MS m/z (%) = 974.26 (100) [M]+

HRMS-ESI+ m/z for C61H41BF2N4O2Zn calcd 974.25821, found 974.25593. UV-Vis (toluene) (log ε): 427 (5.67), 554 (4.34), 589 (3.64) nm.

8

2-[2-Oxo-2-(p-tolyl)ethyl]-5,10,15,20-tetraphenylporphyrin, 6

This compound was obtained in 48% yield from the reaction between 3 and BF3·OEt2. 1H NMR (500 MHz, CDCl3): δ = 8.86 (d, 3JH-H 4.9 Hz, 1H, H-β), 8.84 (d, 3JH-H 4.7 Hz, 1H, H-β), 8.81 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.78 (d, 3JH-

H 4.8 Hz, 1H, H-β), 8.75 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.68 (s, 1H, H-3), 8.59 (d, 3JH-H 4.8 Hz, 1H, H-β), 8.22 (dd, 3JH-H 7.7, 4JH-H 1.6 Hz, 2H, Ho), 8.20 (dd, 3JH-H 7.7, 4JH-H 1.6 Hz, 2H, Ho), 8.17 (dd, 3JH-H 7.9, 4JH-H 1.3 Hz, 2H, Ho), 8.03 (dd, 3JH-H 7.6, 4JH-H 1.6 Hz, 2H, Ho), 7.79-7.65 (m, 11H, 6×Hm + 3×Hp + 2×H-Ar), 7.52-7.49 (m, 3H, 2×Hm + Hp), 7.19(d, 3JH-H 7.9 Hz, 2H, H-Ar), 4.60 (s, 2H, CH2), 2.42(s, 3H, CH3), -2.72 (s, 2H, NH) ppm. 13C NMR (126 MHz, CDCl3): δ 197.46 (C=O), 143.70, 142.63, 142.46, 142.11, 142.04, 134.78, 134.76, 134.66, 134.53, 133.59, 132.1, 131.8, 131.7, 131.6, 131.2, 130.2, 129.10, 128.49, 128.22, 127.82, 127.75, 127.15, 126.87, 126.76, 126.68, 120.52, 120.22, 119.58, 119.56, 41.16, 21.83 (CH3) ppm. ESI+-MS m/z (%) = 747.31 (100) [M + H]+

HRMS-ESI+ m/z for C53H39N4O calcd 747.31239, found 747.31155.

9

NMR spectra

Figure S1. 1H NMR of 2,2-difluoro-4,6-dimethyl-2H-13,3,24-dioxaborinine 7 in

CDCl3.

Figure S2. 13C NMR of 2,2-difluoro-4,6-dimethyl-2H-13,3,24-dioxaborinine 7 in

CDCl3.

10

Figure S3. 19F-NMR of 2,2-difluoro-4,6-dimethyl-2H-13,3,24-dioxaborinine 7 in

CDCl3.

Figure S4. 1H NMR of 2,2-difluoro-4,6-di-p-tolyl-2H-13,3,24-dioxaborinine 8 in

CDCl3.

11

Figure S5. 13C NMR of 2,2-difluoro-4,6-di-p-tolyl-2H-13,3,24-dioxaborinine 8 in

CDCl3.

Figure S6. 19F NMR of 2,2-difluoro-4,6-di-p-tolyl-2H-13,3,24-dioxaborinine 8 in

CDCl3.

12

Figure S7. 1H NMR of 2-(1-acetyl-2-oxopropyl)-5,10,15,20-tetraphenylporphyrin 2 in

CDCl3.

Figure S8. 13C NMR of 2-(1-acetyl-2-oxopropyl)-5,10,15,20-tetraphenylporphyrin 2 in

CDCl3.

13

Figure S9. 1H NMR of [2-(1-acetyl-2-oxopropyl)-5,10,15,20-

tetraphenylporphyrinato]zinc(II) Zn2 in CDCl3.

Figure S10. 13C NMR of [2-(1-acetyl-2-oxopropyl)-5,10,15,20-

tetraphenylporphyrinato]zinc(II) Zn2 in CDCl3.

14

Figure S11. 1H NMR of 2-(1-(p-tolyl)methanone-2-oxo-2-(p-tolyl)ethyl)-5,10,15,20-

tetraphenylporphyrin 3 in CDCl3.

Figure S12. 13C NMR of 2-(1-(p-tolyl)methanone-2-oxo-2-(p-tolyl)ethyl)-5,10,15,20-

tetraphenylporphyrin 3 in CDCl3.

15

Figure S13. 1H NMR of [2-(1-(p-tolyl)methanone-2-oxo-2-(p-tolyl)ethyl)-5,10,15,20-

tetraphenylporphyrinato]zinc(II) Zn3 in CDCl3.

Figure S14. 13C NMR of [2-(1-(p-tolyl)methanone-2-oxo-2-(p-tolyl)ethyl)-5,10,15,20-

tetraphenylporphyrinato]zinc(II) Zn3 in CDCl3.

16

Figure S15. 1H NMR of 2-(2,2-difluoro-4,6-dimethyl-2H-13,3,24-dioxaborinin-5-yl)-

5,10,15,20-tetraphenylporphyrin 4 in CDCl3.

Figure S16. 13C NMR of 2-(2,2-difluoro-4,6-dimethyl-2H-13,3,24-dioxaborinin-5-yl)-

5,10,15,20-tetraphenylporphyrin 4 in CDCl3.

17

Figure S17. 19F-NMR of 2-(2,2-difluoro-4,6-dimethyl-2H-13,3,24-dioxaborinin-5-yl)-

5,10,15,20-tetraphenylporphyrin 4 in CDCl3.

Figure S18. 1H NMR of [2-(2,2-difluoro-4,6-dimethyl-2H-13,3,24-dioxaborinin-5-yl)-

5,10,15,20-tetraphenylporphyrinato]zinc(II) Zn4 in CDCl3.

18

Figure S19. 13C NMR of [2-(2,2-difluoro-4,6-dimethyl-2H-13,3,24-dioxaborinin-5-

yl)-5,10,15,20-tetraphenylporphyrinato]zinc(II) Zn4 in CDCl3.

Figure S20. 19F NMR of [2-(2,2-difluoro-4,6-dimethyl-2H-13,3,24-dioxaborinin-5-

yl)-5,10,15,20-tetraphenylporphyrinato]zinc(II) Zn4 in CDCl3.

19

Figure S21. 1H NMR of 7-(2,2-difluoro-4,6-di-p-tolyl-2H-13,3,24-dioxaborinin-5-yl)-

5,10,15,20-tetraphenylporphyrin 5 in CDCl3.

Figure S22. 13C NMR of 7-(2,2-difluoro-4,6-di-p-tolyl-2H-13,3,24-dioxaborinin-5-

yl)-5,10,15,20-tetraphenylporphyrin 5 in CDCl3.

20

Figure S23. 19F NMR of 7-(2,2-difluoro-4,6-di-p-tolyl-2H-13,3,24-dioxaborinin-5-yl)-

5,10,15,20-tetraphenylporphyrin 5 in CDCl3.

Figure S24. 1H NMR of [7-(2,2-difluoro-4,6-di-p-tolyl-2H-13,3,24-dioxaborinin-5-

yl)-5,10,15,20-tetraphenylporphyrinato]zinc(II) Zn5 in CDCl3.

21

Figure S25. 13C NMR of [7-(2,2-difluoro-4,6-di-p-tolyl-2H-13,3,24-dioxaborinin-5-

yl)-5,10,15,20-tetraphenylporphyrinato]zinc(II) Zn5 in CDCl3.

Figure S26. 19F NMR of [7-(2,2-difluoro-4,6-di-p-tolyl-2H-13,3,24-dioxaborinin-5-

yl)-5,10,15,20-tetraphenylporphyrinato]zinc(II) Zn5 in CDCl3.

22

Figure S27. 1H NMR of 2-(2-oxo-2-(p-tolyl)ethyl)-5,10,15,20-tetraphenylporphyrin 6 in

CDCl3.

Figure S28. 13C NMR of 2-(2-oxo-2-(p-tolyl)ethyl)-5,10,15,20-tetraphenylporphyrin 6

in CDCl3.

23

References 1 H. K. Hombrecher, V. M. Gherdan, S. Ohm, J. A. S. Cavaleiro, M. G. P. M. S. Neves, M. F. Condesso, Tetrahedron, 1993, 49, 8569–8578. 2 F. Giuntini, M. A. F. Faustino, M. G. P. M. S. Neves, A. C. Tomé, A. M. S. Silva, J. A. S. Cavaleiro, Tetrahedron, 2005, 61, 10454–10461. 3 N. Dege, I. Yildirim, A. Güldeste, H. Inaç, I. Koca, N. Kahveci, A. Özyetis, O. Büyükgüngör, Acta Cryst., 2005, E61, o60-o62. A. Sakai, E. Ohta, Y. Yoshimoto, M. Tanaka, Y. Matsui, K. Mizuno, H. Ikeda, Chem. Eur. J. 2015, 21, 18128-18137. 4 A. G. Mirochnik, B. V. Bukvetskii, E. V. Gukhman, P. A. Zhikhareva, V. E. Karasev, Russian Journal of General Chemistry, 2002, 72, 5, 737-740. V. E. Karasev, O. A. Korotkikh, Zh. Neorg. Khim., 1986, 31, 4, 869. 5 A. Sakai, E. Ohta, Y. Yoshimoto, M. Tanaka, Y. Matsui, K. Mizuno, H. Ikeda, Chem. Eur. J. 2015, 21, 18128-18137. 6 F. Giuntini, M. A. F. Faustino, M. G. P. M. S. Neves, A. C. Tomé, A. M. S. Silva, J. A. S. Cavaleiro, Tetrahedron, 2005, 61, 10454–10461.