reactions: palladium-mediated radical homo-coupling a ... · catalysis, and 0.0567 after catalysis....

1

Electronic Supplementary Information

Palladium-mediated radical homo-coupling

reactions:

a surface catalytic insight

Isabelle Favier,a Marie-Lou Toro,a Pierre Lecante,b Daniel Pla,*a and Montserrat Gómez*a

a Laboratoire Hétérochimie Fondamentale et Appliquée (LHFA), Université de Toulouse 3 – Paul Sabatier and

CNRS UMR 5069, 118 route de Narbonne, 31062 Toulouse Cedex 9, France.

b Centre d’Elaboration de Matériaux et d’Etudes Structurales (CEMES), CNRS UPR 8011, 29 rue J. Marvig, 31055

Toulouse, France

TABLE OF CONTENTS

A. Materials and Instrumentation, General Experimental Procedures S2-S4

B. Characterization of preformed palladium nanoparticles, PdXNPs (Figs. S1 – S3) S5-S6

C. Reaction Optimization Studies (Table S1) S7

D. TEM analysis after catalysis (Fig. S4) S8

E. TEM analysis of Pd/C dispersed in glycerol (Fig. S5) S8

F. Halide effect studies (Table S2) S9

G. Determination of bromine content by X-ray fluorescence measurements S10

H. Mechanistic insights for the homo-coupling reaction (Figs. S6 et S7) S11-S12

I. Characterization of bis-aryls 4, 6-8, 10, 11, 13 S13-S16

J. 1H, 13C, and 19F NMR Spectra of Selected Compounds 4, 6-8, 10, 11, 13 S17-S23

K. References S24

Electronic Supplementary Material (ESI) for Catalysis Science & Technology.This journal is © The Royal Society of Chemistry 2018


2

A. General Experimental Procedures, Materials and Instrumentation.

Instrumentation. Automated flash chromatography was performed with an Isco Teledyne

Combiflash medium-pressure liquid chromatograph with prepacked C18 (15 m) or silica gel

(47-60 m) columns. NMR spectra were recorded on a Bruker Advance 300 spectrometer at 293

K (300 MHz for 1H NMR and 75.4 MHz for 13C NMR). Chemical shifts (δ) are reported in ppm

referenced to the appropriate residual solvent peaks and coupling constants are reported in Hz. The

multiplicity of signals is indicated using the following abbreviations: s = singlet, d = doublet, t =

triplet, q = quadruplet, bs = broad singlet, bd = broad doublet, m = multiplet. Raman spectra were

recorded with a Jobin and Yvon Lambram HR800 equipped with a helium neon laser (excitation

line at 532 nm). DRX analyses were run by the Technical platform of the ICT (“Institut de Chimie

de Toulouse”, FR2599). X-Ray diffraction patterns were collected at room temperature on a

PANalytical X’Pert MPD Pro (θ-θ) diffractometer using Cu Kα1,Kα2 radiation. X-ray

fluorescence measurements were performed in Energy Dispersive mode using the silicon drift

detector installed on the WAXS diffractometer at CEMES (Amptek X-123 Super SDD, energy

resolution 125 eV FWHM @ 5.9 keV). The source was a sealed tube with Mo anode operated at

50kV, so both Br and Pd K alpha lines could be effectively accessed (11.7-11.9 keV and 20.7-21.2

keV respectively). TEM analyses were run at the “Centre de MicroCaractérisation Raimond

Castaing”. TEM micrographs of nanoparticles were obtained both dispersed in glycerol from a

JEOL JEM 1400 microscope at 120 kV. The size distribution and average diameter were

determined from TEM images based on Image-J software and a Microsoft Excel macro developed

by Christian Pradel permitting to determine the mean size of spherical nanoparticles with the

corresponding standard deviation for an important number of nanoparticles (thousands of them).

EPR spectra were recorded on a Bruker Elexsys E500 spectrometer (Oxford).


3

GC-MS analyses were performed on a GC Perkin Elmer Clarus 500 with a flame ionization

detector (FID) using a SGE BPX5 column (30 m x 0.32 mm x 0.25 mm) composed of 5%

phenylmethylsiloxane and a Perkin Elmer Clarus 560 S mass spectrometer. The injector

temperature was 250 °C and the flow was 2 mL/min. The temperature programme was 45 °C for

2 min, 20 °C/min to 300 °C, hold for 5 min.

Materials. Glycerol was dried under vacuum at 80 °C overnight prior to use. All reagents and

other chemicals were purchased at the highest commercial quality and used without further

purification unless noted otherwise. Solvents used for organic compounds extractions after

catalysis: EtOAc, PhMe and/or CHCl3. All reactions were performed under Ar atmosphere using

standard Schlenk techniques and vacuum-line manipulations. The synthesis of the Pd

Nanoparticles were performed in a Fischer-Porter bottle and the catalytic reactions in Schlenk

tubes.

General Experimental Procedures.

Synthesis of PdNPs in glycerol. 0.10 mmol of palladium precursor (36 mg for PdI2; 27 mg for

PdBr2; 18 mg for PdCl2; 9.1 mg for Pd(OAc)2; and PVP (Mn = 10000; 222 mg; Pd/monomer =

1/20) were dissolved in degassed glycerol (10 mL) and mixed under vacuum at r.t. in a Fischer-

Porter bottle for 2 min. The system was then pressurized under 3 bar of H2 and stirred at 80 °C

overnight, resulted in a black colloidal suspension. Palladium NPs in the solid state (black powder)

were isolated from glycerol solutions by centrifugation at 4000 rpm for 3 x 10 min and then

decantation by adding acetone and ethanol.

General experimental procedure for the homocoupling of bromoarenes. An oven-dried

Schlenk tube was charged with the starting material (1.0 mmol, 1 equiv.), KOH (1.0 mmol, 1

equiv.), and hydroquinone (0.5 mmol, 1 equiv.) under Ar. The catalytic solution in glycerol was

then transferred to the reaction vessel under Ar. The reaction mixture was heated to 90 ºC and it


4

was vigorously stirred with a PTFE coated Niobium magnetic stirrer for 18 h. The catalytic

solution was then extracted with EtOAc (PhMe or CHCl3) and the combined organic extracts

were then evaporated under reduced pressure. The reaction crudes were then analyzed by 1H-

NMR or GC-MS using dodecane or 1,1,2,2-tetrachloroethane as internal standards. The reaction

crude was then purified by silica gel flash chromatography to furnish the desired homocoupling

products (4-13).


5

B. Characterization of preformed palladium nanoparticles, PdXNPs

Figure S1. Powder X-Ray Diffraction diffractograms of palladium nanoparticles stabilized by

PVP: PdOAcNPs, PdClNPs, PdBrNPs, and PdINPs. For each of them, the XRD pattern

corresponding to the fcc Pd(0) structure is added with the assignment of the corresponding

crystallographic planes (COD code: 00-005-0681).


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Figure S2. XPS survey spectrum for PdOAcNPs (left) and the corresponding high-resolution

spectrum in the Pd 3d binding energy region (right). Note: the binding energies for PdO appear at

ca. 337 and 342 eV.

Figure S3. Raman spectra for PdOAcNPs, PdClNPs, PdBrNPs, and PdINPs (blue traces) and

their corresponding palladium precursors (Pd(OAc)2, PdCl2, PdBr2, and PdI2; orange traces). *

denotes artefact signal.


7

C. Reaction Optimization Studies

Table S1. Reaction optimization conditions for the homo-coupling reaction of 4’-bromoacetophenone with preformed PdNPs prepared from Pd(OAc)2, named PdOAcNPs.

Br PdOAcNPs (1 mol%)base, glycerol, T

OHHO

O

Me

Me

O

O

Me

O

Me

+

Entry HQ Base T (ºC) Conv. (%)a Yield (%)a Selectivity ratio(bis-aryl:acetophenone)a

1 1 equiv. --- 90 44b 39 9:1

2 1 equiv. NaOH1 equiv. 90 68b 17b 11:1b

3 1 equiv. KOH1 equiv. 90 68 61 9:1

4 1 equiv. Na2CO31 equiv. 90 60b 23b 9:1b

5 1 equiv. Et3N1 equiv. 90 65 52 7:1

6 --- KOH1 equiv. 90 24 6 3:7

7 0.5 equiv.

KOH1 equiv. 90 57 55 18:1

8 2 equiv. KOH1 equiv. 90 66 59 9:1

9 6 equiv. KOH1 equiv. 90 4b n.d. 1:1b

10 1 equiv. KOH1 equiv. 120 86 75 7:1

11e 1 equiv. KOH1 equiv. 90 37 6 2.25:1

All reactions were carried out at 1 mmol scale of substrate and 1 mol % of catalyst (1 mL of preformed catalytic solution), and heated to 90 °C for 18 h (unless otherwise stated). After 18 h the catalytic phase was analyzed by GC-MS (EI+) with EtOH. After extraction with CH2Cl2 (7x3 mL) the « crude » product was analyzed by both GC-MS (EI+) and 1H NMR with an internal standard (internal standard (IS), 1 mmol > n(IS) > 0.1 mmol). Not determined (n.d.); a Determined by 1H RMN; b Determined by GC-MS (with dodecane as standard); c Reaction carried out at 2 mmol of substrate; d 60 h reaction time; e Results when the catalytic phase was reused in a 2nd run, from that used in the catalytic reaction of entry 7 in Table 1 of the main text.


8

D. TEM analysis after catalysis

Figure S4. TEM analysis of PdOAcNPs after being used in catalysis (from the experiment

described in entry 7 of Table 1 of the main text)

E. TEM analysis of Pd/C dispersed in glycerol

Figure S5. TEM analysis of commercial Pd/C (10 wt % metal loading on matrix activated

carbon support) dispersed in glycerol.


9

F. Halide effect studies

Table S2. Halide effect study on the homo-coupling reaction using preformed PdNPs as catalysts in glycerol.

BrPd NPs (1 mol%)KOH, additiveglycerol, 90 °C

OHHO

O

Me

Me

O

O

Me

(1 equiv.)

O

Me

+

Entry KOH PdNPs AdditiveConv.

(%)Selectivity

(bis-aryl:acetophenone)Yield

(bis-aryl)

11

equiv.PdOAcNPs

KI

0.20

equiv.

9% 5.6:4.4 5%

20.2

equiv.PdOAcNPs

NMe3 OH

1 equiv.

67% 9.4:0.6 63%

3 --- PdOAcNPsNMe3 OH

1 equiv.

33% 9.1:0.9 30%

41

equiv.PdOAcNPs

NaOAc

2 equiv.64% 9.4:0.6 60%

51

equiv.PdINPs

NaOAc

2 equiv.8% 2.5:7.5 2%

All reactions were carried out at 1 mmol scale of substrate and 1 mol % of catalyst (1 mL of preformed catalytic solution), and heated to 90 °C for 18 h (unless otherwise stated). After 18 h the catalytic phase was analyzed by GC-MS (EI+) with EtOH. After extraction with CH2Cl2 (7x3 mL) the « crude » product was analyzed by both GC-MS (EI+) and 1H NMR with an internal standard (internal standard (IS), 1 mmol > n(IS) > 0.1 mmol). Not determined (n.d.); a 72 h.


10

G. Determination of bromine content by X-ray fluorescence measurements

PdBrNPs, before and after catalysis, were sealed in low absorption glass capillaries of 1.5 mm in

diameter. Since the instrument only provides raw fluorescence data, another sample of PdBr2 was

also prepared as a reference. In order to get low and similar global absorption (so-called matrix

effect), pure PdBr2 was carefully dispersed in a large amount of PVP. For all samples,

measurement time was 2 h.

Using the calibration from PdBr2, the molar ratio Br/Pd could be estimated to 0.0274 before

catalysis, and 0.0567 after catalysis. Uncertainty is difficult to estimate and may be as high as 10%,

but these results clearly indicate a strong increase of the Br/Pd ratio after catalysis due to the release

of bromine from the substrate (4-bromoacetophenone).


11

H. Mechanistic insights for the homo-coupling reaction.A comparative analysis between the experimental EPR spectrum and a simulation of the the corresponding spectra of anion radical species of 4′-bromoacetophenone (I), hydroquinone (II) and acetophenone (III) do not match with the presence of acetophenone radicals in the reaction mixture.

Figure S6. EPR spectra: a) Experimental EPR spectrum of the reaction sample; b) Superposition of simulated EPR spectra of the anion radical species of 4′-bromoacetophenone (I), hydroquinone (II) and acetophenone radical (III); c) Simulated EPR spectrum of 4′-bromoacetophenone anion radical (species I); d) Simulated EPR spectrum of hydroquinone anion radical (species II); e) Simulated EPR spectrum of acetophenone radical (species III).


12

Further experiments to elucidate the role of the base on the reaction mechanism were carried out.

In particular we sought if the hypothesized highly reactive aryl-radical species (Ar•) arising from

fragmentation of aryl radical anion [Ar–X]•− could react with an arene to give a cyclohexadienyl

radical, which would be then deprotonated with KOH to generate a biaryl radical anion. This

radical anion could then transfer an electron to another molecule of aryl bromide reactant to yield

the desired product along with an arene radical anion [Ar–X]•−, thereby closing the catalytic

cycle.1 However, our tests employing up to 10 equiv. excess of different arenes [namely,

fluorobenzene, α,α,α-trifluorotoluene and 1,3-bis(trifluoromethyl)benzene] were unsuccessful to

provide any cross-coupling product.

Br

O

Me

Br

O

Me

SET

KBr

O

Me

R1 = F; R2 = HR1 = CF3; R2 = HR1, R2 = CF3

O

Me

OMe

H

R2 R1

R2 R1

R1R2

O

Me

R2 R1

KOH

KK

H2O

n.d.

Figure S7. A base-promoted homolytic aromatic substitution mechanism has been refuted.

n.d. denotes not detected.


13

I. Characterization of bis-aryls 4, 6-8, 10, 11, 13.

XX DP-I-105-F1114 DP-II-198-F1519Me

O

Me

O

4,4’-Bisacetylbiphenyl (4). Following the general procedure for the homo-coupling reaction and

starting from 1 (995.2 mg, 5.0 mmol), the product was obtained as a white solid (404.0 mg, 68%)

by silica gel chromatography and elution with pentane/EtOAc (100:0 and 80:20). Characterization

data matches literature reports.2, 3

1H NMR (300 MHz, CDCl3) δ 8.06 (d, J = 8.7 Hz, 4H), 7.72 (d, J = 8.7 Hz, 4H), 2.65 (s, 6H). 13C

NMR (75 MHz, CDCl3) δ 197.7, 144.5, 136.7, 129.1, 127.6, 26.9. MS (EI) 238 (M), 239 (M+1).

XX DP-I-108-F0405F3C

CF3

4,4’-Trifluoromethylbiphenyl (6). Following the general procedure for the homo-coupling

reaction and starting from 4-bromo-1-trifluoromethylbenzene (140 µL, 1.0 mmol), the product was

obtained as a white solid (94.1 mg, 65%) by silica gel chromatography and elution with

pentane/EtOAc (100:0 and 95:5). Characterization data matches literature reports.4

1H NMR (300 MHz, CDCl3) δ 7.80-7.69 (m, 8H). 13C NMR (75 MHz, CDCl3) δ 143.4, 130.4 (d,

J = 32.5 Hz), 127. 8, 126.1 (q, J = 3.8 Hz), 124.3 (d, J = 272.1 Hz). 19F NMR (282 MHz, CDCl3)

δ -62.6. MS (EI) 290 (M), 291 (M+1).


14

XX DP-II-145-F1012

F

F

4,4'-difluorobiphenyl (7). Following the general procedure for the homo-coupling reaction and

starting from 1-bromo-4-fluorobenzene (110 µL, 1.0 mmol), the product was obtained as a white

solid (63.7 mg, 67%) by silica gel chromatography and elution with pentane/EtOAc (100:0 and

90:10). Characterization data matches literature reports.5, 6

1H NMR (300 MHz, CDCl3) δ 7.55 – 7.45 (m, 4H), 7.18 – 7.07 (m, 4H). 13C NMR (75 MHz,

CDCl3) δ 162.6 (d, J = 246.4 Hz), 136.5 (d, J = 3.4 Hz), 128.7 (d, J = 8.0 Hz), 115.8 (d, J = 21.5

Hz). 19F NMR (282 MHz, CDCl3) δ -115.8 (ddd, J = 14.0, 8.8, 5.3 Hz). MS (EI) 190 (M), 191

(M+1).

XX DP-I-116Me

Me

4,4′-Dimethylbiphenyl (8). Following the general procedure for the homo-coupling reaction and

starting from 4-bromotoluene (123 µL, 1.0 mmol), the product was obtained as a white solid (10.9

mg, 12%) by silica gel chromatography and elution with pentane/EtOAc (100:0 and 95:5).

Characterization data matches literature reports.2, 7, 8

1H NMR (300 MHz, CDCl3) δ 7.52 (d, J = 8.2 Hz, 4H), 7.27 (d, J = 7.6 Hz, 1H), 2.43 (s, 6H).

13C NMR (75 MHz, CDCl3) δ 138.4, 136.8, 129.6, 126.9, 21.2. MS (EI) 182 (M), 183 (M+1).


15

XX DP-I-146-F2933CF3

CF3

3,3'-Bis(trifluoromethyl)biphenyl (10). Following the general procedure for the homo-coupling

reaction and starting from 3-bromo-1-trifluoromethylbenzene (140 µL, 1.0 mmol), the product was

obtained as a yellowish oil (124.7 mg, 86%) by silica gel chromatography and elution with

pentane/EtOAc (100:0 and 90:10). Characterization data matches literature reports.9, 10

1H NMR (300 MHz, CDCl3) δ 7.84 (bs, 2H), 7.80 – 7.75 (m, 2H), 7.71 – 7.64 (m, 2H), 7.62 (d, J

= 7.6 Hz, 2H). 13C NMR (75 MHz, CDCl3) δ 140.7, 131.6 (d, J = 32.5 Hz), 130.7 (d, J = 1.5 Hz),

129.7, 127.0 (s), 124.9 (q, J = 3.8 Hz), 124.2 (q, J = 3.8 Hz), 124.2 (d, J = 272.4 Hz). 19F NMR

(282 MHz, CDCl3) δ -62.6. MS (EI) 291 (M+1).

XXDP-II-201-F1415CF3

CF3

CF3F3C

3,5,3',5'-Tetrakis(trifluoromethyl)biphenyl (11). Following the general procedure for the homo-

coupling reaction and starting from 3,6-bis(trifluoromethyl)bromobenzene (173 µL, 1.0 mmol),

the product was obtained as a white solid (40.5 mg, 19%) by silica gel chromatography and elution

with pentane. Characterization data matches literature reports.11


16

1H NMR (300 MHz, CDCl3) δ 8.03 (bs, 4H), 7.99 (d, J = 0.8 Hz, 2H). 13C NMR (75 MHz, CDCl3)

δ 140.6, 133.0 (q, J = 33.8 Hz), 127.7 (d, J = 2.9 Hz), 125.0 (t, J = 272.6 Hz), 122.8 (sep, J = 4.1

Hz). 19F NMR (282 MHz, CDCl3) δ -62.9. MS (EI) 427 (M+1).

XX DP-I-111-F0507F

F

2,2'-Difluorobiphenyl (13). Following the general procedure for the homo-coupling reaction and

starting from 1-bromo-2-fluorobenzene (109 µL, 1.0 mmol), the product was obtained as a white

solid (67.5 mg, 71%) by silica gel chromatography and elution with pentane/EtOAc (100:0 and

90:10). Characterization data matches literature reports.12, 13

1H NMR (300 MHz, CDCl3) δ 7.47 – 7.36 (m, 4H), 7.31 – 7.17 (m, 4H). 13C NMR (75 MHz, CDCl3) δ

160.0 (dd, J = 249.8, 1.7 Hz), 131.7 (t, J = 2.5 Hz), 129.9 (t, J = 4.2 Hz), 124.2 (t, J = 1.8 Hz), 123.7 (dd,

J = 9.7, 5.5 Hz), 117.34 – 115.12 (m). 19F NMR (282 MHz, CDCl3) δ -114.8 (d, J = 6.0 Hz). MS (EI) 190

(M), 191 (M+1).


17

J. 1H, 13C, and 19F NMR Spectra of Selected Compounds 4, 6-8, 10, 11, 13.

2.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

pla_d_300b.11.fidhfa SYMACDP-I-108-F0405

3.78

4.00

7.26

7.69

7.69

7.71

7.71

7.72

7.72

7.73

7.74

7.76

7.76

7.77

405060708090100110120130140150160170180190200f1 (ppm)

pla_d_300b.12.fidhfa SYMACDP-I-108-F0405 76

.73

77.1

677

.58

122.

4512

6.02

126.

0512

6.07

126.

1212

6.17

127.

7813

0.23

130.

66

143.

39

-200-190-180-170-160-150-140-130-120-110-100-90-80-70-60-50-40-30-20-100102030f1 (ppm)

pla_d_300a.4.fidhfa SYMACDP-I-108-F0405 -6

2.59


18

405060708090100110120130140150160170180190200f1 (ppm)


122.

3612

4.08

124.

1312

4.18

124.

2312

4.81

124.

8612

4.91

124.

9612

5.97

127.

7012

9.68

130.

6513

0.67

131.

4213

1.85

140.

72

-200-190-180-170-160-150-140-130-120-110-100-90-80-70-60-50-40-30-20-100102030f1 (ppm)

pla_d_300a.7.fidhfa SYMACDP-I-146-F2933 -6

2.64

2.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)


1.93

1.92

2.02

2.00

7.60

7.63

7.65

7.66

7.66

7.66

7.67

7.68

7.68

7.69

7.69

7.76

7.76

7.77

7.77

7.78

7.79

7.79

7.79

7.80

7.84


19

-200-190-180-170-160-150-140-130-120-110-100-90-80-70-60-50-40-30-20-100102030f1 (ppm)

pla_d_300a.6.fidhfa SYMACDP-I-145-F1012

-115

.82

-115

.80

-115

.78

-115

.77

-115

.75

-115

.74

-115

.72

405060708090100110120130140150160170180190200f1 (ppm)


.74

77.1

677

.58

115.

6811

5.97

128.

6612

8.76

136.

5113

6.55

160.

9316

4.19

2.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)


4.00

4.06

7.08

7.09

7.10

7.11

7.12

7.12

7.13

7.13

7.14

7.15

7.16

7.26

7.46

7.47

7.48

7.49

7.49

7.49

7.50

7.51

7.52

7.53


20

405060708090100110120130140150160170180190200f1 (ppm)


115.

6411

5.77

115.

8711

5.97

116.

0711

6.20

123.

5512

3.62

123.

6812

3.75

124.

1712

4.19

124.

2112

9.83

129.

8912

9.94

131.

7013

1.73

131.

7715

8.30

158.

3216

1.61

161.

63

-200-190-180-170-160-150-140-130-120-110-100-90-80-70-60-50-40-30-20-100102030f1 (ppm)

pla_d_300a.5.fidhfa SYMACDP-I-111-F0507

-114

.83

-114

.79

2.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)


4.12

4.00

7.17

7.18

7.20

7.21

7.23

7.23

7.25

7.28

7.28

7.30

7.37

7.40

7.41

7.43

7.44

7.45

7.46


21

1.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.010.5f1 (ppm)


5.90

4.00

3.97

2.65

7.26

7.71

7.71

7.71

7.73

7.73

7.73

8.04

8.05

8.05

8.07

8.07

8.07

0102030405060708090100110120130140150160170180190200f1 (ppm)


.86

76.7

477

.16

77.5

8

127.

5812

9.14

136.

70

144.

46

197.

71


22

0102030405060708090100110120130140150160170180190200f1 (ppm)


.23

76.7

477

.16

77.5

8

126.

9312

9.56

136.

8113

8.41

1.01.52.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.010.5f1 (ppm)


6.01

4.10

4.00

2.43

7.26

7.26

7.28

7.29

7.29

7.51

7.53


23

2.02.53.03.54.04.55.05.56.06.57.07.58.08.59.09.510.0f1 (ppm)

pla_d_300b.24.fidhfa SYMACDP-II-201-F1415

2.00

4.04

7.26

7.99

7.99

8.03

0102030405060708090100110120130140150160170180190200f1 (ppm)

pla_d_300b.26.fidhfa SYMACDP-II-201-F1415 76

.74

77.1

677

.58

121.

3412

2.67

122.

7212

2.78

122.

8212

2.88

124.

9612

7.63

127.

6712

8.57

132.

3713

2.82

133.

2713

3.71

140.

55

-200-190-180-170-160-150-140-130-120-110-100-90-80-70-60-50-40-30-20-100102030f1 (ppm)

pla_d_300a.8.fidhfa SYMACDP-II-201-F1415 -6

2.86


24

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reactions: palladium-mediated radical homo-coupling a ... · catalysis, and 0.0567 after catalysis....

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