Supporting information for
Two-step, Catalytic C-C Bond Oxidative Cleavage
Process Converts Lignin Models and Extracts to
Aromatic Acids
Min Wang,† Jianmin Lu,† Xiaochen Zhang,† Lihua Li,† Hongji Li,†, ‡ Nengchao
Luo,†, ‡ and Feng Wang*,†
†
State Key Laboratory of Catalysis, Dalian National Laboratory for Clean Energy, Dalian
Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, P. R. China.
‡
University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
* Corresponding Author: [email protected]
Table of Contents
1. General considerations
2. General procedure for oxidation of β-O-4 alcohol to β-O-4 ketone
3. General procedure for oxidation of Alcell lignin
4. General procedure for oxidative cleavage of β-O-4 ketone
5. Procedure for the growth of copper/1,10-phenanthroline complex single crystal
6. DFT calculations
7. Synthesis of lignin model compounds and details of NMR Characterization
8. Detection of reaction gas phase product
Experimental section
1. General considerations
All of the chemicals were of analytical grade, mostly purchased from J&K Chemicals
and Aladdin Chemicals, and were used without further purification. 1H and 13C NMR
spectra were obtained with a Bruker AVANCE III 400 MHz spectrometer with
tetramethylsilane used as the internal reference. Multiplicities are described by using
the following abbreviations: s = singlet, d = doublet, t = triplet, q = quartet, sept =
septet and m = multiplet. 2D-NMR spectra were acquired on a Agilent VAVCE III
HD 700MHz spectrometer. The standard Agilent implementations of HSQC
experiments were used. Electron paramagnetic resonance (EPR) tests were performed
on a Bruker spectrometer in the X-band at 77 K with a field modulation of 100 kHz.
The microwave frequency was maintained at 9.401 GHz. The structure change of the
organosolv lignin was determined by 2D NMR (HSQC) analysis of the samples
before and after oxidation. The signal intensity before and after treatment of the
organosolv lignin were normalized relative to the signal of protons in methoxyl
groups on the assumption that methoxyl groups was expected to remain unchanged
during the reaction. Single X ray diffraction was performed on Agilent GeminiUltra
diffractometer. A CHI 650 potentiostat (Shanghai Chenhua) was used for the
electrochemical measurements in a conventional three-electrode electrochemical cell
installed with platinum foil as the counter electrode and Hg/HgO electrode as the
reference electrode. The cyclic voltammetry (CV) curves of samples were examined
in 1.0 M KCl and 0.1 M copper salts aq. at a scan rate of 100 mV s-1. All
electrochemical measurements were performed at 25 oC.
2. Procedure for the growth of copper/1,10-phenanthroline complex single
crystal
The gas-liquid diffusion method was adopted for the growth of single crystal.
Typically, 50 mg Cu(OAc)2 and 50 mg of 1,10-phenanthroline were added into a
bottle (20 mL) with 6 mL MeOH. After dissolving by ultrasonic, the bottle was put
into a jar (250 mL) with 50 mL diethyl ether. Then the jar was sealed and put into
freezer. After two days, blue crystals appeared.
3. Procedures of oxidation of β-O-4 alcohol to β-O-4 ketone
The catalytic reactions were performed in a 10-mL autoclave reactor with an internal
Teflon insert. Typically, 0.5 mmol of substrate, 0.1 mmol VOSO4, 0.1 mmol TEMPO,
and 2 mL of MeCN were added to the reactor. Then, the reactor was charged with 0.4
MPa O2, heated to 100 oC and maintained for 12 h under magnetic stirring. Then, the
reaction mixture was diluted with 4 mL ethanol. The products were identified and
quantified using gas chromatography-mass spectrometry (GC-MS) and an Agilent
7890A/5975C instrument equipped with an HP-5 MS column (30 m in length, 0.25
mm in diameter). p-xylene was used as the internal standard.
4. Procedures of oxidation of organosolv lignin
Typically, 0.05 g of Alcell lignin, 0.2 mmol VOSO4, 0.2 mmol TEMPO, and 2 mL of
CD3CN were added to the reactor. Then, the reactor was charged with 0.4 MPa O2,
heated to 100 oC and maintained for 6 h under magnetic stirring. After filtration, the
reaction solution was characterized by 2D HSQC NMR. The products were identified
and quantified using gas chromatography-mass spectrometry (GC-MS) and an Agilent
7890A/5975C instrument equipped with an HP-5 MS column (30 m in length, 0.25
mm in diameter). p-xylene was used as the internal standard.
5. Procedures of the oxidative cleavage of β-O-4 ketone models
The catalytic reactions were performed in a 10-mL autoclave reactor with an internal
Teflon insert. Typically, 0.2 mmol of substrate, 0.04 mmol copper catalyst, and 2 mL
of methanol were added to the reactor. Then, the reactor was charged with 0.4 MPa
O2 and heated to 80 oC under magnetic stirring. When the reaction completed, the
reaction mixture was diluted with 4 mL of methanol. The acid product was esterified
with addition of 40 µl of BF3•OEt2 at 100 oC for 6 h in Ar atmosphere. The products
were identified and quantified using gas chromatography-mass spectrometry (GC-MS)
and an Agilent 7890A/5975C instrument equipped with an HP-5 MS column (30 m in
length, 0.25 mm in diameter). p-xylene was used as the internal standard. Some minor
amount of ester was also observed before esterification. The total yields of the acid
include the ester and acid, and calculated based on the corresponding esters.
6. DFT Calculations
The DFT calculations were performed using the Vienna ab initio simulation package
(VASP)1
with
project
augmented
wave
(PAW)
potential
and
the
Perdew-Burke-Ernzerhof (PBE) functional.2 A plane wave cutoff of 400 eV was used.
The copper/1,10-phenanthroline complex, copper-oxo-bridged dimer and copper
superoxide monomer were fully relaxed in a cubic box with a side length of 30
Angstroms until the residual forces were less than 0.02 eV/Å. The reaction energy of
substrate was calculated by Eads(0) = Etotal – Eslab – Emol(g), where Etotal, Eslab and Emol(g)
are the total energies of the optimized adsorbate/substrate system, the clean substrate,
and the molecule in the gas phase, respectively. Charge transfer has been analysed by
the Bader method.3
(1) Kresse, G.; Furthmuller, J. Comp. Mater. Sci. 1996, 6, 15.
(2) Perdew, J. P.; Burke, K.; Ernzerhof, M. Phys. Rev. Lett. 1996, 77, 3865.
(3) Sanville, E.; Kenny, S. D.; Smith, R.; Henkelman, G. J. Comput. Chem. 2007, 28,
899.
Atomic coordinates in optimized geometries:
The white, gray, blue, red and pink spheres represent H, C, N, O, and Cu,
respectively.
H
6.448898114
16.7901522 14.60101557
H
6.467434505
14.32479304
14.62831235
H
7.795246302
19.01957646
14.55197339
H
10.06181808
20.10537478
14.50465904
H
12.1320652 18.64286579
H
12.16873211
12.56272253
15.00109249
H
10.12321322
11.06652671
14.89817043
H
7.844746962
12.1163559 14.74837796
H
21.40209907
16.80219089
14.73335412
H
21.38794888
14.33647832
14.70687322
H
20.05135293
19.02900498
14.80691502
H
17.78433563
20.10974217
14.90070257
H
15.71791314
18.64143252
14.97301926
H
15.68354146
12.56132559
14.46911861
H
17.73391533
11.07050314
14.52033485
H
20.01324463
12.12563866
14.61577511
C
7.398707336
16.25035173
14.62819692
C
8.617415664
17.01093868
14.62392169
C
9.838814864
16.29196497
14.64637738
C
7.40887414 14.87959588
C
8.705754728
18.41648838
14.57265158
C
9.964404511
19.02004465
14.54649974
14.48527952
14.64559325
C
11.12135622
18.22799086
14.53423228
C
8.637470415
14.13809876
14.70744818
C
9.847209505
14.87614482
14.7384475
C
11.15378894
12.96003202
14.9095059
C
10.01094322
12.15012638
14.84917971
C
8.745462084
12.73407598
14.7662091
C
20.45316613
16.26025516
14.7267253
C
19.23321196
17.01809969
14.75674152
C
18.01331952
16.29640824
14.76252355
C
20.44525605
14.88943784
14.70984497
C
19.14212835
18.42352511
14.8068305
C
17.8831122 19.02451749
C
16.72865673
18.22980835
14.90081645
C
19.21695127
14.14544812
14.67567117
C
18.00527064
14.88058696
14.67301047
C
16.69922314
12.96141968
14.53552469
C
17.8449392 12.15434108
C
19.11089461
12.74125674
14.61972778
N
11.06499466
16.89200394
14.5592715
N
11.07683798
14.29480655
14.87984929
N
16.78874384
16.89427561
14.87812565
N
16.77381074
14.29658531
14.56261067
14.85928927
14.56704907
O
13.9260544 16.86726899
O
13.92683257
14.33451956
Cu 12.5726714 15.60070771
14.76741587
14.76932637
14.74851087
Cu 15.28132814
15.60023095
14.74322251
H
5.583772127
16.80311193
14.58188213
H
5.594041017
14.33250916
14.69914676
H
6.884791877
18.99059685
14.50153658
H
9.13546182 20.12257766
H
11.20344552
18.73354611
14.55623956
H
11.22913556
12.45339833
14.84287624
H
9.172240165
11.04573957
14.89645757
H
6.912015104
12.15785412
14.8232509
C
6.528540744
16.25505195
14.61698309
C
7.751724055
17.00396686
14.5944094
C
8.982522528
16.29596872
14.63836618
C
6.53420468 14.88919361
C
7.809150236
18.41016991
14.53300668
C
9.052152549
19.03621263
14.51412082
14.46713161
14.68218394
C
10.21754235
18.2635032 14.56375188
C
7.763385192
14.15122568
14.72963915
C
8.988503434
14.86965521
14.70407209
C
10.23930000
12.91422568
14.81153258
C
9.079987007
12.13105617
14.84112512
C
7.831943791
12.74589345
14.800709
N
10.20505788
16.92155864
14.63390149
N
10.2161271 14.25634502
O
13.76285261
O
13.4591169 15.5956698 15.47443351
15.61495334
14.74865059
14.15599318
Cu 11.68405576
15.60758641
14.85966996
H
5.998968617
16.54220303
13.57268801
H
6.168644097
14.15778676
14.21187767
H
7.122787165
18.68578479
12.82699095
H
9.267922246
19.85684401
12.21830176
H
11.40848101
18.58994928
12.27159716
H
11.9023339 12.61052194
14.15747724
H
9.94573207 11.14337574
14.72207998
H
7.629443641
12.11618814
14.64115973
H
21.20983242
16.9413629 14.69362944
H
21.16762567
14.48026266
14.93076064
H
19.97703834
19.11010459
14.20780837
H
17.78930539
20.22610954
13.64951429
H
15.74527386
18.8300811 13.35282812
H
15.55873078
12.6269782 14.28368047
H
17.57590032
11.20659126
H
19.82531646
12.3102825 14.94816008
H
12.69603842
19.03667267
H
11.49854517
21.2213972 15.17734765
H
9.428584528
17.28699736
17.40542222
H
17.80575262
15.31023244
17.88765748
H
15.62507284
15.4033483 16.74589311
H
17.35944869
19.4121666 19.13758197
H
18.70659073
17.30291557
19.0891912
H
13.62298031
15.58377282
16.55082613
H
9.264428851
21.44937135
16.25297444
H
8.218239674
19.48054019
17.37060986
H
15.12988209
19.49122216
18.02252546
H
13.94317927
14.97681245
11.64146222
C
6.970743418
16.04262321
13.59165123
14.71894287
15.23539846
C
8.13205257 16.80517557
13.23608115
C
9.402834796
16.17412077
13.27074235
C
7.064270154
14.72552372
13.94698899
C
8.080799394
18.16252116
12.85248628
C
9.262795017
18.80773212
12.51772995
C
10.47206753
18.10429886
12.5523787
C
8.334219739
14.06598267
14.00229966
C
9.506268427
14.80509905
13.68634657
C
10.88056578
12.99869727
14.11617444
C
9.780691947
12.18089687
14.42805595
C
8.503493178
12.71824854
14.38211929
C
20.27306447
16.39090959
14.57607021
C
19.08371777
17.13153277
14.26868356
C
17.86233054
16.42460627
14.1112956
C
20.24973308
15.03018204
14.70881534
C
19.05823668
18.53047417
14.09717718
C
17.85135928
19.14582109
13.78785219
C
16.69889822
18.36988721
13.62010336
C
19.02574353
14.29498752
14.57940501
C
17.82626741
15.00797355
14.30896684
C
16.55240785
13.07605289
14.36344543
C
17.68679187
12.28621437
14.60379884
C
18.92916512
12.89615474
14.72990498
C
11.81222063
16.69664161
16.44178994
C
11.7151938 19.13932783
C
11.04003608
20.36012368
15.66876525
C
9.784413184
20.48847231
16.26981245
C
9.196889907
19.38370534
16.89574778
C
9.865139801
18.1621479 16.92072482
C
11.13369413
18.02673929
16.33044925
C
13.30329222
16.53197994
16.07408232
C
17.22536097
16.23544005
17.92610589
C
15.98278368
16.27887284
17.28694747
C
15.22330678
17.45816199
17.32985463
C
15.73476519
18.58265844
18.00188105
C
16.97851421
18.52654808
18.62378896
C
17.73413052
17.34911704
18.59666917
N
10.56734679
16.81186435
12.91784018
N
10.75864457
14.2798933 13.76856651
N
16.68454757
17.03173784
N
16.6003131 14.40811883
O
13.49952593
16.57933276
14.72441873
O
13.79943017
14.89772953
12.59814874
O
13.99444099
17.63407504
16.75923817
15.69906425
13.75283253
14.24027485
O
11.19536445
15.70150604
16.83422997
Cu 12.18966994
15.79496094
13.28079429
Cu 15.13303433
15.81903082
13.70420795
H
13.68832257
13.12197672
15.40880677
H
5.473833305
16.68703793
13.51736036
H
5.483270383
14.22043659
13.70130509
H
6.700577544
18.90914329
13.80354645
H
8.812453663
20.08726022
14.48588365
H
10.79206164
18.73704035
15.21404576
H
10.84235645
12.51799931
15.64194076
H
8.869555331
11.036605
15.14750768
H
6.734580651
12.07859828
14.33173576
H
9.081065927
17.31808065
19.7664999
H
8.305809939
15.61559752
21.43727786
H
11.92251279
14.4868147 18.20937023
H
16.12015215
20.83520584
15.73172668
H
13.91039357
19.83202187
15.16120044
H
16.35136258
18.30507482
19.21340828
H
17.3627803 20.05994972
17.75737365
H
12.9168498 16.20872373
17.45616316
H
9.360403508
13.35541098
H
11.17229115
12.8080136 19.85715291
H
14.1396499 17.34693021
C
6.370378233
16.16186789
13.85582274
C
7.527993354
16.93869905
14.19245208
C
8.699847254
16.26535382
14.62028063
C
6.375323992
14.7973865 13.95644854
C
7.579320571
18.3487879 14.13095609
C
8.743828875
18.99945277
14.5027248
C
9.863936555
18.25423286
14.90685449
C
7.53996924 14.09368129
C
8.703424319
14.83782573
14.73458362
C
9.889582395
12.93374766
15.30834909
C
8.785048723
12.11588443
15.01414395
C
7.607943147
12.69252459
14.56367381
C
10.98007784
17.13368305
17.95407703
C
9.523903954
16.32076801
19.80241922
C
9.099285824
15.36866153
20.72830449
C
9.689713845
14.10209065
20.75343301
C
10.70717611
13.79648313
19.84392919
21.47919812
18.67848088
14.40680422
C
11.13474024
14.74990309
18.91888409
C
10.54795297
16.02839448
18.88638149
C
12.14121821
16.89184604
17.09604301
C
15.69488883
20.06013454
16.37285608
C
14.45901031
19.50775762
16.04713695
C
13.89816828
18.51548493
16.86551231
C
14.57918066
18.09007802
18.01399107
C
15.82517216
18.6457474 18.31886353
C
16.39196864
19.62882591
17.50734804
N
9.856122353
16.91629064
14.94370361
N
9.85295967 14.26205539
O
12.92202816
13.50745536
14.93626098
O
12.98358997
14.87728184
15.45462423
O
12.66739178
18.03930241
16.4727309
O
10.34363124
18.20938451
17.92651687
Cu 11.30380189
15.69845537
15.61031218
16.78195066
14.6971818
H
6.499025982
15.18314991
H
6.596421997
14.47552519
15.57862854
H
7.740041374
18.81439083
13.71710751
H
9.927914194
19.80334362
12.99289769
H
12.02956489
18.41977762
13.20029416
H
12.28793529
12.67729509
15.46140671
H
10.27537246
11.36714478
16.30299018
H
7.997875433
12.41542685
16.19440075
H
16.09177358
17.75563743
15.94880245
H
14.84411923
18.71657599
16.77884132
H
15.24741131
19.03176623
15.04702672
H
15.68155945
11.62948249
13.18030169
H
16.29613599
13.26864442
12.81268326
H
14.99908496
12.59149745
11.81490312
C
7.452565299
16.25173324
14.75078196
C
8.637030226
16.9244478 14.30307898
C
9.873680866
16.23559493
14.37025272
C
7.507040206
14.97394361
15.23839523
C
8.667154525
18.2412547 13.79102527
C
9.87504179 18.78961229
C
11.05355243
18.02802533
13.49671389
C
8.748140961
14.26022672
15.32643205
C
9.931841139
14.90080200
14.8858561
C
11.26546677
13.07881531
15.43989662
C
10.13734839
12.37133641
15.90068341
C
8.882639846
12.95139518
15.84244889
C
15.12285984
18.2621497 15.81996356
C
14.09600841
17.23310649
15.41191224
C
15.39868153
12.63189787
12.83735407
C
14.38774505
13.24673865
13.79607566
N
11.05017061
16.78153475
13.96692832
13.39158856
N
11.15862872
14.31335931
14.9422359
O
13.40245406
16.61474245
16.25986568
O
13.97425545
16.98797098
14.13998681
O
14.21215447
12.77439331
14.93555491
O
13.77763619
14.28690586
13.29653269
Cu
12.6341604 15.50722369
14.27457476
7. Synthesis of model compounds and detailed NMR characterization
Procedure for preparation of 2-phenoxy-1-phenylethanone
2-Phenoxy-1-phenylethanone was prepared by the literature procedures.4 A 350 mL
pressure bottle was charged with phenol (6.9 g，73 mmol) and K2CO3 (10.4 g，75
mmol) in acetone (150 mL) in Ar atmosphere and stirred at RT for 30 min. To this
solution, 2-bromoacetophenone (14.0 g, 70 mmol) was added, the resulting
suspension was stirred at RT for 16 h, after which the suspension was filtered and
concentrated in cacuo. The solid was dissolved in ethyl acetate and washed with
NaOH aqueous (5%, 30ml) and water (30ml). The organic phase was dried over
anhydrous Na2SO4. The crude product was recrystallized from ethanol to give
2-phenoxy-1-phenylethanone as a white solid in 87% yield. Spectral data were in
accordance with those previously reported. For the other methoxyl substituted
2-phenoxy-1-phenylethanone, the preparation procedure is the same as described
above, except that using different stating materials.
Procedure for preparation of 2-phenoxy-1-phenylethanol
2-Phenoxy-1-phenylethanol was prepared by the literature procedures.5 A 100 mL
pressure bottle was charged with 2-phenoxy-1-phenylethanone (2.12 g, 10 mmol) and
THF/water solvent (50 mL, 4:1 volume ration ) was added. NaBH4 (0.76 g, 20 mmol)
was added in one portion and stirred at r.t. for 1 h. Then, an excess of saturated NH4Cl
aqueous solution (30 mL) was added. The crude product was extracted with ethyl
acetate (3 × 20 mL). The combined organic extracts were washed with brine (100 mL)
and dried over anhydrous Na2SO4. The organic solvent was distilled under vacuum to
2-phenoxy-1-phenylethanol as a white solid. Spectral data were in accordance with
those
previously
reported.
For
the
other
methoxyl
substituted
2-phenoxy-1-phenylethanol, the preparation procedure is the same as described above,
except that using different stating materials.
Procedure for preparation of phenolic lignin model
2-phenoxy-1-(4-hydroxyphenzyl) ethanone
The 1-(4-hydroxyphenzyl)-2-phenoxy-ethanone was prepared using a reported
procedure with small modification. To a solution of sodium methylate (0.54 g) in
THF (20 mL) was added phenol (0.94 g), the mixture was stirred at room temperature
for 1 h to get sodium phenate. Then 2-bromo-1-(4-hydroxyphenzyl) ethanone (2.16 g)
was added, the mixture was stirred for another 5 h. After reaction, the solvent was
removed by evaporation under reduced pressure. The residue was purified over
column silica gel (EtOAc: petroleum ether = 1 : 1) to get the product as a white solid.
1-(4-hydroxyphenzyl)-2-phenoxy-ethanol
1-(4-hydroxyphenzyl)-2-phenoxy-ethanol was prepared by the reduction of
2-phenoxy-1-(4-hydroxyphenzyl) ethanone with NaBH4. The procedure is the same as
the preparation of none-phenolic lignin model.
1
H NMR (400 MHz, DMSO) δ = 9.33 (s, 1H), 7.33 – 7.19 (m, 4H), 6.90 (t, J=7.9
Hz, 3H), 6.76 (t, J=9.5 Hz, 2H), 5.46 (d, J=4.5 Hz, 1H), 4.84 (dt, J=6.8, 4.7 Hz, 1H),
4.01 – 3.90 (m, 2H).
13
C NMR (101 MHz, DMSO) δ = 159.06, 157.13, 133.16,
130.15, 129.90, 128.02, 120.94, 115.30, 114.99, 73.57, 71.12.
Procedure for preparation of
1-(3,4-dimethoxyphenyl)-3-hydroxy-2-(2-methoxyphenoxy)propan-1-one
1-(3,4-dimethoxyphenyl)-3-hydroxy-2-(2-methoxyphenoxy)propan-1-one
was
prepared by the literature procedures.4 To a stirring suspension of K2CO3 (0.6 g, 4.3
mmol) and 1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)ethanone (1.2 g, 4 mmol)
in ethanol: acetone (v/v=1:1, 20 mL), a water solution of formaldehyde (36.5-38%)
(0.6 mL, 7.3 mmol) was added at room temperature. After 4 h the reaction mixture
was concentrated in vacuo to get a solid product. The solid was purified by column
chromatography
(pentane/ethyl
acetate,
1:1)
to
yield
1-(3,4-dimethoxyphenyl)-3-hydroxy-2-(2-methoxyphenoxy)propan-1-one as a little
yellow solid (1.19 g, 3.6 mmol) in 90% yield.
1
H NMR (400 MHz, DMSO) δ = 10.64 – 10.21 (m, 1H), 7.91 (d, J=8.6 Hz, 2H), 7.27
(t, J=7.9 Hz, 2H), 7.03 – 6.79 (m, 5H), 5.44 (s, 2H). 13C NMR (101 MHz, DMSO) δ =
193.06, 163.02, 158.51, 130.93, 129.85, 126.46, 121.22, 115.85, 115.04, 70.09.
Procedure for synthesis of synthesis of the deuterated compounds
2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone (0.50 g 9.19mmol) was added
to a vial with anhydrous K2CO3 (0.126 g, 0.92 mmol) and 5 mL of D2O. The vial was
caped. The reaction ran at 100 °C for 24 h. The D2O was decanted and replaced by
fresh one. The reaction was maintained for additional 24 h at 100 °C. Then the solid
was washed to remove the K2CO3 residues. Finally, the solid was dried under vacuum
to give deuterated compounds as a slightly yellow solid in 95% yield.
(4) Dawange, M.; Galkin, M. V.; Samec, J. S. M. Chemcatchem 2015, 7, 401.
(5) Zhang, J.; Liu, Y.; Chiba, S.; Loh, T. P. Chem. Commun. 2013, 49, 11439.
2-phenoxy-1-phenylethanone
Prepared from 2-bromoacetophenone and phenol in 87% yield. White solid. 1H NMR (400 MHz,
CD2Cl2) δ = 8.08 – 8.00 (m, 2H), 7.73 – 7.64 (m, 1H), 7.56 (dd, J=10.6 Hz, 4.8, 2H), 7.39 – 7.29 (m,
2H), 7.08 – 6.94 (m, 3H), 5.35 (s, 2H). 13C NMR (101 MHz, CD2Cl2) δ = 194.29, 158.12, 134.68,
133.80, 129.54, 128.83, 127.94, 121.47, 114.64, 70.61.
2-(2-methoxyphenoxy)-1-phenylethanone
Prepared from 2-bromoacetophenone and guaiacol in 71% yield. White solid. 1H NMR (400 MHz,
CDCl3) δ = 8.06 – 7.97 (m, 2H), 7.60 (t, J=7.4 Hz, 1H), 7.48 (t, J=7.7 Hz, 2H), 7.02 – 6.82 (m, 4H),
5.34 (s, 2H), 3.88 (s, 3H). 13C NMR (101 MHz, CDCl3) δ = 194.59, 149.86, 147.57, 134.69, 133.74,
128.79, 128.12, 122.52, 120.81, 115.02, 112.27, 72.19, 55.93.
2-(2,6-dimethoxyphenoxy)-1-phenylethanone
Prepared from 2-bromoacetophenone and 2,6-dimethoxyphenol in 43% yield. White solid. 1H NMR
(400 MHz, CDCl3) δ = 8.05 (d, J=7.7 Hz, 2H), 7.56 (t, J=7.3 Hz, 1H), 7.46 (t, J=7.6 Hz, 2H), 7.00 (t,
J=8.4 Hz, 1H), 6.57 (d, J=8.4 Hz, 2H), 5.19 (s, 2H), 3.79 (s, 6H). 13C NMR (101 MHz, CDCl3) δ =
195.19, 153.20, 136.73, 135.24, 133.25, 128.54, 128.36, 124.06, 105.38, 75.44, 56.08.
1-(4-methoxyphenyl)-2-phenoxyethanone
Prepared from 2-bromo-1-(4-methoxyphenyl)ethanone and phenol in 83% yield. White solid. 1H NMR
(400 MHz, CDCl3) δ = 8.00 (d, J=8.8 Hz, 2H), 7.27 (dd, J=13.0 Hz, 4.4, 2H), 7.02 – 6.90 (m, 5H), 5.20
(s, 2H), 3.87 (s, 3H). 13C NMR (101 MHz, CDCl3) δ = 193.13, 164.06, 158.13, 130.58, 129.56, 127.70,
121.57, 114.82, 114.02, 70.76, 55.53.
2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone
Prepared from 2-bromo-1-(4-methoxyphenyl)ethanone and guaiacol in 88% yield. White solid. 1H
NMR (400 MHz, CDCl3) δ = 8.08 – 7.96 (m, 2H), 7.00 – 6.81 (m, 6H), 5.27 (s, 2H), 3.87 (s, 3H), 3.86
(s, 3H). 13C NMR (101 MHz, CDCl3) δ = 193.15, 163.97, 149.78, 147.67, 130.52, 127.75, 122.34,
120.81, 114.79, 113.96, 112.22, 72.02, 55.93, 55.51.
2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone
Prepared from 2-bromo-1-(4-methoxyphenyl)ethanone and 2,6-dimethoxyphenol in 86% yield. White
solid. 1H NMR (400 MHz, CDCl3) δ = 8.10 – 8.02 (m, 2H), 7.04 – 6.90 (m, 3H), 6.57 (d, J=8.4 Hz,
2H), 5.13 (s, 2H), 3.85 (s, 3H), 3.80 (s, 6H). 13C NMR (101 MHz, CDCl3) δ = 193.74, 163.60, 153.26,
136.79, 130.74, 128.33, 124.03, 113.71, 105.39, 75.38, 56.08, 55.45.
1-(3,4-dimethoxyphenyl)-2-phenoxyethanone
Prepared from 2-bromo-1-(3,4-dimethoxyphenyl)ethanone and phenol in 85% yield. Little yellow solid.
1
H NMR (400 MHz, CDCl3) δ = 7.65 (dd, J=8.4 Hz, 1.9, 1H), 7.56 (d, J=1.9 Hz, 1H), 7.35 – 7.23 (m,
2H), 7.03 – 6.86 (m, 4H), 5.21 (s, 2H), 3.93 (d, J=8.5 Hz, 6H). 13C NMR (101 MHz, CDCl3) δ =
193.18, 158.13, 153.93, 149.30, 129.57, 127.81, 122.86, 121.58, 114.82, 110.41, 110.19, 70.73, 56.03.
1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)ethanone
Prepared from 2-bromo-1-(3,4-dimethoxyphenyl)ethanone and guaiacol in 92% yield. Little yellow
solid. 1H NMR (400 MHz, CDCl3) δ = 7.68 (dd, J=8.4 Hz, 1.9, 1H), 7.60 (d, J=1.8 Hz, 1H), 7.02 –
6.82 (m, 5H), 5.29 (s, 2H), 3.98 – 3.86 (m, 9H). 13C NMR (101 MHz, CDCl3) δ = 193.30, 149.76,
149.23, 147.63, 127.89, 122.80, 122.37, 120.83, 114.76, 112.20, 110.50, 110.16, 72.08, 56.11, 56.01,
55.92.
2-(2,6-dimethoxyphenoxy)-1-(3,4-dimethoxyphenyl)ethanone
Prepared from 2-bromo-1-(3,4-dimethoxyphenyl)ethanone and 2,6-dimethoxyphenol in 93% yield.
Little yellow solid. 1H NMR (400 MHz, CDCl3) δ = 7.73 (dd, J=8.4 Hz, 1.9, 1H), 7.65 (d, J=1.9 Hz,
1H), 7.01 (t, J=8.4 Hz, 1H), 6.89 (d, J=8.4 Hz, 1H), 6.58 (d, J=8.4 Hz, 2H), 5.15 (s, 2H), 3.94 (s, 6H),
3.81 (s, 6H). 13C NMR (101 MHz, CDCl3) δ = 193.71, 153.42, 153.27, 149.01, 136.72, 128.42, 124.06,
123.08, 110.72, 110.08, 105.38, 75.30, 56.09.
2-phenoxy-1-phenylethanol
Prepared from 2-phenoxy-1-phenylethanone and NaBH4 in 98% yield. White solid. 1H NMR (400
MHz, CD3CN) δ = 7.46 (d, J=7.3 Hz, 2H), 7.42 – 7.21 (m, 5H), 6.98 – 6.89 (m, 3H), 5.00 (dt, J=7.8 Hz,
4.0, 1H), 4.05 (ddd, J=17.5, 9.9, 5.8 Hz, 2H), 3.68 (d, J=4.0 Hz, 1H). 13C NMR (101 MHz, CD3CN) δ
= 159.36, 142.10, 130.09, 128.84, 128.22, 126.98, 121.42, 117.88, 115.17, 73.62, 72.36.
2-(2-methoxyphenoxy)-1-phenylethanol
Prepared from 2-(2-methoxyphenoxy)-1-phenylethanone and NaBH4 in 94% yield. White solid. 1H
NMR (400 MHz, CD3CN) δ = 7.48 – 7.41 (m, 2H), 7.41 – 7.25 (m, 3H), 6.90 (dddd, J=9.6, 7.8, 5.5,
2.4 Hz, 4H), 4.99 (dt, J=7.8, 3.8 Hz, 1H), 4.05 (ddd, J=18.0, 10.1, 5.9 Hz, 2H), 3.80 (s, 3H), 3.69 (d,
J=3.8 Hz, 1H). 13C NMR (101 MHz, CD3CN) δ = 150.46, 148.93, 142.06, 128.83, 128.21, 127.00,
122.36, 121.51, 117.88, 115.39, 113.08, 75.26, 72.47, 56.07.
2-(2,6-dimethoxyphenoxy)-1-phenylethanol
Prepared from 2-(2,6-dimethoxyphenoxy)-1-phenylethanone and NaBH4 in 87% yield. White solid. 1H
NMR (400 MHz, CD3CN) δ = 7.42 – 7.24 (m, 5H), 7.04 (t, J=8.4 Hz, 1H), 6.68 (d, J=8.4 Hz, 2H), 4.85
(d, J=9.0 Hz, 1H), 4.26 – 4.17 (m, 2H), 3.83 (s, 6H), 3.74 (dd, J=10.7, 9.0 Hz, 1H). 13C NMR (101
MHz, CD3CN) δ = 153.91, 141.16, 137.24, 128.77, 128.07, 126.86, 124.70, 117.88, 106.05, 79.67,
72.60, 56.36.
1-(4-methoxyphenyl)-2-phenoxyethanol
Prepared from 1-(4-methoxyphenyl)-2-phenoxyethanone and NaBH4 in 90% yield. White solid. 1H
NMR (400 MHz, CD3CN) δ = 7.44 – 7.31 (m, 2H), 7.31 – 7.23 (m, 2H), 6.98 – 6.88 (m, 5H), 4.94 (dt,
J=7.3, 3.5 Hz, 1H), 4.02 (qd, J=9.8, 5.9 Hz, 2H), 3.77 (s, 3H), 3.59 (d, J=3.7 Hz, 1H). 13C NMR (101
MHz, CD3CN) δ = 159.85, 159.39, 134.10, 130.09, 128.24, 121.38, 117.88, 115.17, 114.19, 73.60,
71.95, 55.48.
2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol
Prepared from 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone and NaBH4 in 87% yield. White
solid. 1H NMR (400 MHz, CD3CN) δ = 7.35 (t, J=5.7 Hz, 2H), 7.01 – 6.82 (m, 6H), 4.93 (dd, J=7.7,
3.7 Hz, 1H), 4.01 (ddd, J=18.0, 10.0, 6.0 Hz, 2H), 3.76 (t, J=15.3 Hz, 6H), 3.72 (s, 1H). 13C NMR (101
MHz, CD3CN) δ = 159.85, 150.36, 148.93, 134.04, 128.27, 122.26, 121.52, 117.91, 115.18, 114.19,
113.02, 75.18, 72.03, 56.06, 55.48.
2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol
Prepared from 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone and NaBH4 in 84% yield.
White solid. 1H NMR (400 MHz, CD3CN) δ = 7.29 (d, J=8.6 Hz, 2H), 7.04 (t, J=8.4 Hz, 1H), 6.92 –
6.85 (m, 2H), 6.67 (d, J=8.4 Hz, 2H), 4.79 (d, J=9.0 Hz, 1H), 4.22 – 4.13 (m, 2H), 3.83 (s, 6H), 3.78 –
3.67 (m, 4H). 13C NMR (101 MHz, CD3CN) δ = 159.76, 153.91, 137.27, 133.11, 128.15, 124.66,
117.89, 114.15, 106.05, 79.65, 72.20, 56.35, 55.46.
1-(3,4-dimethoxyphenyl)-3-hydroxy-2-(2-methoxyphenoxy)propan-1-one
1
H NMR (400 MHz, CD3CN) δ = 7.75 (dd, J=8.5, 2.0 Hz, 1H), 7.56 (d, J=2.0 Hz, 1H), 7.04 – 6.89 (m,
3H), 6.89 – 6.73 (m, 2H), 5.56 (dd, J=5.5, 4.3 Hz, 1H), 3.99 (td, J = 6.0, 3.3 Hz, 2H), 3.87 (s, 3H), 3.83
(s, 3H), 3.78 (s, 3H), 3.72 (q, J = 5.9 Hz, 1H), 3.23 (dd, J=7.9, 4.5 Hz, 1H). 13C NMR (101 MHz,
CD3CN) δ = 195.86, 154.61, 150.46, 149.73, 147.68, 128.88, 123.96, 122.89, 121.30, 117.90, 116.26,
113.28, 111.50, 111.31, 82.55, 63.63, 56.22, 56.01, 55.98.
70.61
114.64
121.47
127.94
134.68
133.80
158.12
194.29
5.35
7.06
7.04
7.02
6.99
6.99
6.97
7.32
7.55
8.05
8.03
8.03
2-phenoxy-1-phenylethanone
55.93
72.19
115.02
112.27
120.81
128.12
134.69
133.74
149.86
147.57
194.59
3.88
5.34
7.60
7.58
7.50
7.48
7.46
6.98
6.97
6.96
6.95
6.94
6.92
6.90
6.85
6.85
8.02
8.00
2-(1-methoxyphoxy)-1-phenylethanone
56.08
75.44
105.38
136.73
135.24
133.25
128.36
124.06
153.20
195.19
3.79
5.19
6.58
6.56
7.02
7.00
6.98
7.56
7.48
7.44
8.06
8.04
2-(2,6-dimethoxyphenoxy)-1-phenylethanone
55.53
70.76
114.82
114.02
121.57
130.58
129.56
127.70
158.13
164.06
193.13
3.87
5.20
6.99
6.97
6.95
6.94
6.93
7.28
7.26
7.25
8.01
7.99
1-(4-methoxyphenyl)-2-phenoxyethanone
55.93
55.51
72.02
114.79
113.96
112.22
120.81
130.52
127.75
149.78
147.67
163.97
193.15
3.87
3.86
5.27
8.03
8.02
8.01
8.00
8.00
7.99
6.95
6.94
6.94
6.93
6.92
6.91
6.89
6.84
6.83
2-(2-methoxyphenoxy)-1-(4-methoxyphenyl) ethanone
56.08
55.45
75.38
105.39
113.71
128.33
124.03
136.79
153.26
163.60
193.74
3.85
3.80
5.13
6.58
6.56
6.94
6.94
6.93
6.92
8.07
8.07
8.05
8.05
2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl) ethanone
56.03
70.73
114.82
110.41
110.19
121.58
129.57
127.81
158.13
153.93
149.30
193.18
3.94
3.92
5.21
6.97
6.95
6.95
6.93
6.91
6.89
7.26
7.66
7.66
7.64
7.64
7.57
7.56
1-(3,4-dimethoxyphenyl)-2-phenoxyethanone
56.11
56.01
55.92
72.08
114.76
112.20
110.50
110.16
120.83
127.89
149.76
149.23
147.63
193.30
3.95
3.93
3.88
5.29
7.69
7.69
7.67
7.67
7.61
7.60
6.92
6.91
6.90
6.89
6.86
6.85
1-(3,4-dimethoxyphenyl)-2-(2-methoxyphenoxy)ethanone
56.09
75.30
3.94
3.81
5.15
6.59
6.57
6.88
110.72
110.08
105.38
7.28
128.42
124.06
123.08
7.74
7.74
7.72
7.72
7.65
7.65
136.72
153.42
153.27
149.01
193.71
2-(2,6-dimethoxyphenoxy)-1-(3,4-dimethoxyphenyl)ethanone
73.62
72.36
121.42
117.88
115.17
128.22
126.98
142.10
130.09
159.36
3.68
3.67
5.02
5.01
5.00
4.99
4.98
4.09
4.07
4.02
3.99
6.96
6.94
6.93
6.92
6.91
7.37
7.37
7.35
7.32
7.32
7.32
7.31
7.30
7.29
7.29
7.28
7.27
7.26
7.25
7.25
7.45
2-phenoxy-1-phenylethanol
56.07
75.26
72.47
128.83
128.21
127.00
122.36
121.51
117.88
115.39
113.08
142.06
150.46
148.93
5.01
5.00
4.99
4.98
4.97
4.11
4.10
4.08
4.07
4.03
4.01
4.00
3.98
3.80
3.69
3.68
6.88
6.86
6.84
7.46
7.45
7.44
7.38
7.38
7.37
7.36
7.35
7.32
7.31
7.31
7.30
7.29
7.28
6.95
2-(2-methoxyphenoxy)-1-phenylethanol
56.36
72.60
79.67
106.05
128.77
128.07
126.86
124.70
117.88
141.16
137.24
153.91
3.83
3.77
3.74
3.74
3.72
4.19
4.86
4.84
4.24
6.69
6.66
7.39
7.39
7.37
7.35
7.34
7.33
7.32
7.29
7.29
7.27
7.02
2-(2,6-dimethoxyphenoxy)-1-phenylethanol
55.48
73.60
71.95
121.38
117.88
115.17
114.19
134.10
130.09
128.24
159.85
159.39
4.96
4.95
4.94
4.93
4.92
4.03
3.99
3.97
3.77
3.59
3.58
6.93
6.92
6.92
6.91
6.91
7.38
7.37
7.37
7.36
7.35
7.35
7.29
7.29
7.27
7.26
7.25
1-(4-methoxyphenyl)-2-phenoxyethanol
56.06
55.48
75.18
72.03
122.26
121.52
117.91
115.18
114.19
113.02
128.27
134.04
150.36
148.93
159.85
4.95
4.94
4.93
4.92
4.07
4.06
4.04
4.03
4.00
3.98
3.98
3.96
3.80
3.77
3.72
6.93
6.91
6.89
6.87
6.84
7.37
7.35
7.34
2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol
56.35
55.46
72.20
79.65
106.05
114.15
124.66
137.27
133.11
153.91
159.76
4.19
4.18
4.17
4.16
4.16
4.00
3.94
3.83
3.76
3.74
3.72
3.71
3.69
3.64
3.58
4.80
4.78
6.89
6.86
6.68
6.66
7.30
7.28
7.27
2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol
8. Detection of reaction gas phase product
Figure S1. Limewater images before (left) and after (right) introduction of the
reaction gas phase.