Abstract: The valorization of lignin via mild reductive depolymerization has gained increasing interest, but various knowledge gaps regarding the underlying reaction mechanism continue to hinder the rational optimization of the process conditions. In order to fill these gaps, this work investigates both solvolytic and catalytic mild reductive depolymerization of a hydrolysis lignin at different reaction times (15 min – 10 h) and temperatures (150 °C – 200 °C). Novel insights into the depolymerization of (technical) lignins were achieved by investigating the modification of native end groups (NEGs), defined as para-substituted side chains attached to the end of the lignin polymers before depolymerization such as formyl and 3-oxo-1-propenyl. These were found to be stable in solvolysis but highly reactive in catalysis with Pd/γ-Al₂O₃. Furthermore, this work introduces a new catalytic reaction mechanism, whereby β-O-4-derived propanol side chains are converted into ethyl side chains at elevated temperatures. At 150 °C, these propanol groups remained largely intact, whereas at 200 °C, up to 40 % were transformed into ethyl chains. The findings further highlight distinctive depolymerization pathways for solvolysis and catalysis. Solvolysis proceeds via a “peeling-off” mechanism, while catalysis involves random cleavage of β-O-4 linkages. This results in a higher degree of depolymerization and monomer yield under catalytic conditions (up to 9 wt% compared to approximately 3 wt% for solvolysis). In both cases, the majority of depolymerization occurs within the first 3 h of reaction. Finally, it was proven that the Pd catalyst plays a primordial role in the modification of β-β and β-5 linkages, which remain stable under solvolytic conditions.

Keywords: Lignin ; Mild reductive depolymerization ; Heterogeneous catalysis ; Reaction mechanisms ; Bio-aromatics

Purchased from AmBeed: 6766-82-1 ; 19037-58-2 ; 2305-13-7 ; 20736-25-8 ; 4206-58-0 ; 14059-92-8

Aromatic monomers analysis for reductive catalytic fractionation of lignin by liquid chromatography with diode array detection

Woodworth, Sean P ; Ramirez, Kelsey J ; Beckham, Gregg T ;

DOI: 10.17504/protocols.io.bp2l6x6jdlqe/v1 Springer Nature,2025.

Abstract: An analysis method was developed to quantify the products of lignin derived reductive catalytic fractionation (RCF) by high pressure liquid chromatography paired with diode array detection (HPLC-DAD). This was achieved through chromatographic separation using a mobile phase gradient to separate aromatic analytes on a HPLC reverse phase analytical column.

Keywords: lignin ; c18 ; aromatic acids ; gradient ; UHPLC ; DAD ; HST ; lignin-derived aromatics ; RCF ; Reductive catalytic fractionation

Purchased from AmBeed: 2305-13-7

Enhancing the performance of heterogeneous palladium based catalysts in the mild reductive depolymerization of Soda lignin through addition of a non-noble metal and tuning of the preparation strategy

Tibo De Saegher ; Boyana Atanasova ; Pieter Vermeir ; Kevin M. Van Geem ; Jeriffa De Clercq ; An Verberckmoes , et al.

DOI: 10.1039/D4SU00054D RSC Sustain.,2024,2,1551-1567.

Abstract: Research towards mild reductive depolymerization of lignin is gaining momentum because of its potential for producing sustainable functionalized aromatics, but achieving high yields still relies on expensive noble metal catalysts. This study aims to improve the catalysts' cost effectiveness through addition of a non-noble metal to a Pd nanoparticle catalyst, supported on γ-Al2O3. Six Pd based catalysts (Pd, PdCu, PdNi, PdFe, PdCo, and PdMo) were synthesized and prepared through either calcination or thermal reduction, and their activity and selectivity in lignin depolymerization were evaluated as a function of batch time. Principal component analysis (PCA) of the entire datapool revealed that, albeit to varying degrees, the addition of a secondary metal shifts the behavior of a Pd catalyst more towards that of pure solvolysis and that the preparation strategy has no effect on Pd and PdMo. Regarding activity, it was found that the addition of Cu, Ni, Fe, Co and Mo significantly enhances the catalyst's activity and that the preparation strategy is also important, with calcination being preferred for PdCu and PdFe and thermal reduction for PdNi and PdCo. Using a plethora of analysis techniques to assess the selectivity at increasing depths, it was revealed that the shift in selectivity, as identified in the PCA results, is caused by variations in dehydration of aliphatic OH groups and hydrogenation of aliphatic double bonds. Moreover, due to a size exclusion effect during the reaction, differences in selectivity between the catalysts are most pronounced at lower molecular weights.

Purchased from AmBeed: 2305-13-7

Product Details of Dihydroconiferyl alcohol

CAS No. :	2305-13-7
Formula :	C₁₀H₁₄O₃
M.W :	182.22
SMILES Code :	OC1=CC=C(CCCO)C=C1OC
Synonyms :	Dihydroconiferyl alcohol
MDL No. :	MFCD00016571
InChI Key :	MWOMNLDJNQWJMK-UHFFFAOYSA-N
Pubchem ID :	16822

Safety of Dihydroconiferyl alcohol

GHS Pictogram:
Signal Word:	Warning
Hazard Statements:	H315-H319-H335
Precautionary Statements:	P261-P305+P351+P338

Application In Synthesis of Dihydroconiferyl alcohol

* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.

Downstream synthetic route of [ 2305-13-7 ]

[ 2305-13-7 ] Synthesis Path-Downstream 1~54

1
[ 110-86-1 ]
[ 2305-13-7 ]
[ 122-04-3 ]
[ 22805-51-2 ]

References: [1]Journal of the American Chemical Society,1948,vol. 70,p. 57.

2
[ 64-17-5 ]
[ 61292-90-8 ]
[ 2305-13-7 ]

References: [1]Journal of the American Chemical Society,1948,vol. 70,p. 57.

3
[ 2305-13-7 ]
[ 6245-54-1 ]

References: [1]Chemische Berichte,1939,vol. 72,p. 367,370.
Nippon Kagaku Kaishi,1939,vol. 60,p. 276.
[2]Chemische Berichte,1939,vol. 72,p. 1146,1151.
Nippon Kagaku Kaishi,1939,vol. 60,p. 513,517.

4
[ 458-35-5 ]
[ 2305-13-7 ]

References: [1]Zhurnal Obshchei Khimii,1950,vol. 20,p. 1199,1207.
J. Gen. Chem. USSR (Engl. Transl.),1950,vol. 20,p. 1243.
[2]Journal of Organic Chemistry,1959,vol. 24,p. 736,738.
[3]Acta Chemica Scandinavica (1947),1961,vol. 15,p. 357 - 369.
[4]Phytochemistry,1981,vol. 20,p. 1543 - 1546.

5
[ 1135-23-5 ]
[ 2305-13-7 ]

References: [1]Zhurnal Obshchei Khimii,1958,vol. 28,p. 3265,3267, 3268; engl. Ausg. S. 3291.
[2]Phytochemistry,1990,vol. 29,p. 1653 - 1659.

6
[ 61292-90-8 ]
[ 2305-13-7 ]

References: [1]Sci. Rep. Tohoku Univ., Ser. 1: Phys., Chem., Astron.,vol. 17,p. 694.
Chem.Abstr.,1928,p. II, 1325.

7
2-hydroxy-5-(3-hydroxy-propyl)-3-methoxy-benzoic acid [ No CAS ]
[ 2305-13-7 ]

References: [1]Chemische Berichte,1939,vol. 72,p. 367,370.
Nippon Kagaku Kaishi,1939,vol. 60,p. 276.

8
[ 7452-86-0 ]
[ 2305-13-7 ]

References: [1]Journal of the American Chemical Society,1948,vol. 70,p. 63,64, 66.

9
[ 2305-13-7 ]
[ 103-71-9 ]
2-methoxy-1-phenylcarbamoyloxy-4-(3-phenylcarbamoyloxy-propyl)-benzene [ No CAS ]

References: [1]Chemische Berichte,1939,vol. 72,p. 367,370.
Nippon Kagaku Kaishi,1939,vol. 60,p. 276.

10
[ 2305-13-7 ]
[ 106-95-6 ]
[ 130447-88-0 ]

References: [1]Synlett,2005,p. 3011 - 3013.
[2]European Journal of Organic Chemistry,2015,vol. 2015,p. 2470 - 2481.
[3]Chemische Berichte,1939,vol. 72,p. 1146,1151.
Nippon Kagaku Kaishi,1939,vol. 60,p. 513,517.

11
[ 186581-53-3 ]
[ 2305-13-7 ]
[ 85774-53-4 ]
[ 85774-52-3 ]

References: [1]Canadian Journal of Chemistry,1983,vol. 61,p. 545 - 549.

12
[ 97-53-0 ]
[ 2305-13-7 ]
[ 20736-21-4 ]

References: [1]Synlett,2005,p. 3011 - 3013.
[2]European Journal of Organic Chemistry,2015,vol. 2015,p. 2470 - 2481.
[3]Acta chemica Scandinavica. Series B: Organic chemistry and biochemistry,1980,vol. 34,p. 15 - 20.

13
[ 24589-78-4 ]
[ 2305-13-7 ]
2-Methoxy-1-trimethylsilanyloxy-4-(3-trimethylsilanyloxy-propyl)-benzene [ No CAS ]

References: [1]Phytochemistry,1990,vol. 29,p. 1653 - 1659.

14
[ 1117-96-0 ]
[ 2305-13-7 ]
1-(4-ethoxy-3-methoxyphenyl)propane-1,3-diol [ No CAS ]

References: [1]Agricultural and Biological Chemistry,1985,vol. 49,p. 2325 - 2330.

15
[ 2305-13-7 ]
[ 78765-33-0 ]

References: [1]Chemistry of Natural Compounds,1991,vol. 27,p. 648 - 649.
Khimiya Prirodnykh Soedinenii,1991,p. 732 - 733.

16
[ 2305-13-7 ]
[ 85774-51-2 ]
[ 85774-50-1 ]

References: [1]Canadian Journal of Chemistry,1983,vol. 61,p. 545 - 549.

17
[ 458-35-5 ]
[ 2305-13-7 ]

References: [1]Angewandte Chemie - International Edition,2014,vol. 53,p. 7785 - 7788.
Angew. Chem.,2014,vol. 53,p. 7919 - 7922,4.
[2]Phytochemistry,2006,vol. 67,p. 1765 - 1780.
[3]Phytochemistry,1993,vol. 33,p. 1395 - 1402.

18
[ 56024-44-3 ]
[ 2305-13-7 ]

References: [1]Synthetic Communications,1988,vol. 18,p. 1765 - 1772.
[2]Phytochemistry,1990,vol. 29,p. 1653 - 1659.
[3]Phytochemistry,1992,vol. 31,p. 1179 - 1184.
[4]Tetrahedron Letters,1999,vol. 40,p. 6561 - 6562.

19
[ 5155-65-7 ]
[ 2305-13-7 ]

References: [1]Chemische Berichte,1969,vol. 102,p. 3803 - 3817.

20
[ 2305-13-7 ]
[ 23951-09-9 ]

References: [1]Canadian Journal of Chemistry,1970,vol. 48,p. 477 - 479.

21
[ 2305-13-7 ]
[ 90564-28-6 ]

References: [1]Bulletin of the Academy of Sciences of the USSR Division of Chemical Science,1964,p. 1163 - 1166.
Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya,1964,p. 1254 - 1260.

22
[ 2305-13-7 ]
[ 108-24-7 ]
[ 22753-28-2 ]

References: [1]Journal of the Indian Chemical Society,1994,vol. 71,p. 645 - 648.

23
Veratrylglycerin-β-dihydroconiferylether [ No CAS ]
[ 2305-13-7 ]

References: [1]Chemische Berichte,1966,vol. 99,p. 2638 - 2651.

24
[ 97133-59-0 ]
[ 2305-13-7 ]

References: [1]Chemische Berichte,1966,vol. 99,p. 2638 - 2651.

25
[ 458-36-6 ]
[ 2305-13-7 ]
[ 458-35-5 ]

References: [1]Journal of Agricultural and Food Chemistry,1996,vol. 44,p. 2942 - 2943.

26
[ 97-53-0 ]
[ 2305-13-7 ]

References: [1]Bioorganic and Medicinal Chemistry Letters,1997,vol. 7,p. 3081 - 3084.

27
[ 2305-13-7 ]
[ 108-24-7 ]
[ 22753-28-2 ]
[ 14574-06-2 ]

References: [1]Bioorganic and Medicinal Chemistry Letters,1997,vol. 7,p. 3081 - 3084.
[2]Bioorganic and Medicinal Chemistry Letters,1997,vol. 7,p. 3081 - 3084.

28
[ 2305-13-7 ]
[ 108-24-7 ]
[ 22753-28-2 ]
[ 201361-84-4 ]

References: [1]Bioorganic and Medicinal Chemistry Letters,1997,vol. 7,p. 3081 - 3084.

29
[ 2305-13-7 ]
[ 108-24-7 ]
[ 22753-28-2 ]
Acetic acid 3-(2-bromo-4-hydroxy-5-methoxy-phenyl)-propyl ester [ No CAS ]

References: [1]Bioorganic and Medicinal Chemistry Letters,1997,vol. 7,p. 3081 - 3084.

30
[ 2305-13-7 ]
[ 76-83-5 ]
2-methoxy-4-(3-trityloxy-propyl)-phenol [ No CAS ]
3-(3-methoxy-4-trityloxy-phenyl)-propan-1-ol [ No CAS ]

References: [1]Tetrahedron Letters,1999,vol. 40,p. 6561 - 6562.

31
[ 2305-13-7 ]
[ 18162-48-6 ]
4-[3-(tert-Butyl-dimethyl-silanyloxy)-propyl]-2-methoxy-phenol [ No CAS ]

References: [1]Tetrahedron Letters,1999,vol. 40,p. 6561 - 6562.

34
3-<4-acetoxy-3-methoxy-phenyl>-propionyl chloride [ No CAS ]
[ 2305-13-7 ]

References: [1]Journal of Organic Chemistry,1959,vol. 24,p. 736,738.

35
maple wood [ No CAS ]
[ 2305-13-7 ]

References: [1]Journal of the American Chemical Society,1948,vol. 70,p. 57.

36
[ 2305-13-7 ]
[ 7732-18-5 ]
oxygen [ No CAS ]
enzyme-substance from mushrooms [ No CAS ]
[ 110-15-6 ]
[ 4482-31-9 ]
[ 485-38-1 ]

References: [1]Chemische Berichte,1949,vol. 82,p. 447,450.

37
[ 64-17-5 ]
[ 67-66-3 ]
[ 2305-13-7 ]
aqueous KOH [ No CAS ]
[ 6245-54-1 ]

References: [1]Chemische Berichte,1939,vol. 72,p. 367,370.
Nippon Kagaku Kaishi,1939,vol. 60,p. 276.

38
[ 60-29-7 ]
[ 107682-24-6 ]
LiAlH₄ [ No CAS ]
[ 2305-13-7 ]
[ 3063-86-3 ]

References: [1]Monatshefte fur Chemie,1963,vol. 94,p. 530 - 536.

39
forest plant material [ No CAS ]
[ 124-38-9 ]
[ 201230-82-2 ]
[ 2305-13-7 ]
[ 458-35-5 ]

References: [1]Chemosphere,2000,vol. 41,p. 735 - 741.

40
[ 2305-13-7 ]
7-methoxy-1-oxaspiro[4.5]deca-6,9-dien-8-one [ No CAS ]

References: [1]Tetrahedron,2001,vol. 57,p. 319 - 329.

41
[ 2305-13-7 ]
[ 141-78-6 ]
[ 14574-06-2 ]

References: [1]Synthetic Communications,2002,vol. 32,p. 249 - 252.

42
[ 2305-13-7 ]
[ 80638-48-8 ]

References: [1]Phytochemistry,2006,vol. 67,p. 1765 - 1780.
[2]Bioscience, Biotechnology and Biochemistry,2011,vol. 75,p. 1770 - 1777.

43
[ 2305-13-7 ]
[ 854665-55-7 ]