Journal of the American Chemical Society
Communication
(3) (a) Ibrahim, W.; Lundquist, K. Acta Chem. Scand. 1994, 48, 149.
of the β−O−4-linked diols in lignin proceeds with high
selectivity, similar to that seen with the simpler model
compounds.
These results provide an important foundation for future
efforts focused on selective C−C bond cleavage reactions.
Preliminary studies toward this end are encouraging. Treatment
of benzylic ketone 3 with H2O2 under basic conditions afforded
veratric acid (9) in 88% yield together with a 42% yield of
guaiacol (10) (Scheme 2; see the SI for further details). These
́
(b) Martínez, A. T.; Rencoret, J.; Marques, G.; Gutier
́
rez, A.; Ibarra, D.;
Jimenez-Barbero, J.; del Río, J. C. Phytochemistry 2008, 69, 2831.
́
(c) Vanholme, R.; Demedts, B.; Morreel, K.; Ralph, J.; Boerjan, W. Plant
Physiol. 2010, 153, 895.
(4) (a) Cui, F.; Wijesekera, T.; Dolphin, D. J. Biotechnol. 1993, 30, 15.
(b) Cui, F.; Dolphin, D. Bioorg. Med. Chem. 1995, 3, 471. (c) Herrmann,
W. A.; Weskamp, T.; Zoller, J. P.; Fischer, R. W. J. Mol. Catal. A: Chem.
2000, 153, 49. (d) Crestini, C.; Caponi, M. C.; Argyropoulos, D. S.;
Saladino, R. Bioorg. Med. Chem. 2006, 14, 5292. (e) Partenheimer, W.
Adv. Synth. Catal. 2009, 351, 456. (f) Zhang, J.; Deng, H.; Lin, L.
Molecules 2009, 14, 2747.
(5) (a) Drago, R. S.; Corden, B. B.; Barnes, C. W. J. Am. Chem. Soc.
1986, 108, 2453. (b) Artaud, I.; Ben-Aziza, K.; Mansuy, D. J. Org. Chem.
1993, 58, 3373. (c) Bozell, J. J.; Hames, B. R.; Dimmel, D. R. J. Org.
Chem. 1995, 60, 2398. (d) Kumar, A.; Jain, N.; Chauhan, S. M. S. Synlett
2007, 411. (e) Badamali, S. K.; Luque, R.; Clark, J. H.; Breeden, S. W.
Catal. Commun. 2009, 10, 1010. (f) Pandey, M. P.; Kim, C. S. Chem. Eng.
Technol. 2011, 34, 29.
Scheme 2. Preliminary Study of Selective C−C Bond Cleavage
(6) (a) Son, S.; Toste, D. Angew. Chem., Int. Ed. 2010, 49, 3791.
(b) Hanson, S. K.; Baker, R. T.; Gordon, J. C.; Scott, B. L.; Thorn, D. L.
Inorg. Chem. 2010, 49, 5611. (c) Hanson, S. K.; Wu, R.; Silks, L. A.
Angew. Chem., Int. Ed. 2012, 51, 3410. (d) Zhang, G.; Scott, B. L.; Wu,
R.; Silks, L. A.; Hanson, S. A. Inorg. Chem. 2012, 51, 7354.
(7) Tarabanko, V. E.; Fomova, N. A.; Kuznetsov, B. N.; Ivanchenko, N.
M.; Kudryashev, A. V. React. Kinet. Catal. Lett. 1995, 55, 161.
(8) (a) Hoover, J. M.; Stahl, S. S. J. Am. Chem. Soc. 2011, 133, 16901.
(b) Hoover, J. M.; Steves, J. E.; Stahl, S. S. Nat. Protoc. 2012, 7, 1161.
(9) (a) Larock, R. C.; Hightower, T. R. J. Org. Chem. 1993, 58, 5298.
(b) Steinhoff, B. A.; Stahl, S. S. J. Am. Chem. Soc. 2006, 128, 4348.
(10) Brink, G.-J.; Arends, I. W. C. E.; Hoogenraad, M.; Verspui, G.;
Sheldon, R. A. Adv. Synth. Catal. 2003, 345, 1341.
conditions were derived from previously reported methods for
oxidative cleavage of diketones and α-alkoxy ketones with
H2O2.17 Although they are not necessarily optimized for the
present application, they nevertheless provide strong support for
the proposed lignin-conversion strategy illustrated in Figure 2.
In summary, we have identified a highly effective catalytic
method for chemoselective aerobic oxidation of benzylic 2°
alcohols in the presence of unprotected 1° alcohols, which are
prevalent in lignin. The optimized catalyst system is entirely
metal-free, consisting of a readily available TEMPO derivative
and mineral acids, and is potentially suitable for large-scale
conversion applications. Successful demonstration of this
oxidation method with authentic lignin validates the utility of
chemically and structurally faithful model compounds in the
development of lignin-conversion technologies.
(11) Ma, S.; Liu, J.; Li, S.; Chen, B.; Cheng, J.; Kuang, J.; Liu, Y.; Wan,
B.; Wang, Y.; Ye, J.; Yu, Q.; Yuan, W.; Yu, S. Adv. Synth. Catal. 2011, 353,
1005.
(12) (a) Strazzolini, P.; Runcio, A. Eur. J. Org. Chem. 2003, 526.
(b) Wang, X.; Liu, R.; Jin, Y.; Liang, X. Chem.Eur. J. 2008, 14, 2679.
(c) Naimi-Jamal, M. R.; Hamzeali, H.; Mokhtari, J.; Boy, J.; Kaupp, G.
ChemSusChem 2009, 2, 83. (d) Kuang, Y.; Rokubuichi, H.; Nabae, Y.;
Hayakawa, T.; Kakimoto, M.-a. Adv. Synth. Catal. 2010, 352, 2635.
(e) Shibuya, M.; Osada, Y.; Sasano, Y.; Tomizawa, M.; Iwabuchi, Y. J.
Am. Chem. Soc. 2011, 133, 6497. (f) Aellig, C.; Neuenschwander, U.;
Hermans, I. ChemCatChem 2012, 4, 525. (g) Tanielyan, S. K.;
Augustine, R. L.; Marin, N.; Alvez, G.; Stapley, J. Top. Catal. 2012, 55,
556.
ASSOCIATED CONTENT
* Supporting Information
Full catalyst screening data, experimental procedures, and
characterization data for all products. This material is available
■
S
(13) (a) Labat, G.; Meunier, B. J. Org. Chem. 1989, 54, 5008.
(b) Crestini, C.; D’Auria, M. Tetrahedron 1997, 53, 7877. (c) Cyr, A.;
AUTHOR INFORMATION
Corresponding Author
■
Chiltz, F.; Jeanson, P.; Martel, A.; Brossard, L.; Lessard, J.; Men
́
ard, H.
Can. J. Chem. 2000, 78, 307.
(14) (a) Tuor, U.; Wariishi, H.; Schoemaker, H. E.; Gold, M. H.
Biochemistry 1992, 31, 4986. (b) Crestini, C.; Pastorini, A.; Tagliatesta,
P. J. Mol. Catal. A: Chem. 2004, 208, 195. (c) Crestini, C.; Pro, P.; Neri,
V.; Saladino, R. Bioorg. Med. Chem. 2005, 13, 2569. (d) Crestini, C.;
Caponi, M. C.; Argyropoulos, D. S.; Saladino, R. Bioorg. Med. Chem.
2006, 14, 5292. (e) Crestini, C.; Crucianelli, M.; Orlandi, M.; Saladino,
R. Catal. Today 2010, 156, 8.
(15) The catalyst loading was selected by dividing the mass of dried
lignin by the molar mass of 1 to estimate the amount of diol fragments.
(16) Ralph, J.; Landucci, L. L. In Lignin and Lignans: Advances in
Chemistry; Heitner, C., Dimmel, D., Schmidt, J. A., Eds.; CRC Press:
Boca Raton, FL, 2010; pp 137−234. (b) Kim, H.; Ralph, J. Org. Biomol.
Chem. 2010, 8, 576. (c) Ralph, S. A.; Landucci, L. L.; Ralph J. NMR
(17) (a) Omori, S.; Dence, C. W. Wood Sci. Technol. 1981, 15, 113.
(b) Sawaki, Y.; Foote, C. S. J. Am. Chem. Soc. 1983, 105, 5035.
(c) Lanzalunga, O.; Bietti, M. J. Photochem. Photobiol., B 2000, 56, 85.
Notes
The authors declare the following competing financial
interest(s): A patent application has been submitted based on
this work.
ACKNOWLEDGMENTS
■
This work was funded by the DOE Great Lakes Bioenergy
Research Center (DOE BER Office of Science DE-FC02-
07ER64494). NMR facilities were partially supported by the
NSF (CHE-9208463) and NIH (S10 RR08389).
REFERENCES
■
(1) (a) Annual Energy Review 2011; DOE/EIA-0384(2011); U.S.
Energy Information Administration: Washington, DC, 2012. (b) Ralph,
J.; Brunow, G.; Boerjan, W. Lignins. In eLS; Wiley: 2007.
(2) (a) Collinson, S. R.; Thielemans, W. Coord. Chem. Rev. 2010, 254,
1854. (b) Zakzeski, J.; Bruijnincx, P. C. A.; Jongerius, A. L.;
Wechhuysen, B. M. Chem. Rev. 2010, 110, 3552.
D
dx.doi.org/10.1021/ja401793n | J. Am. Chem. Soc. XXXX, XXX, XXX−XXX