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reaction and filtration, the filtrate was transferred into a 250 mL
roundbottom flask. Under cooling with ice, 4.0 g NaBH4 was slowly
added to the solution, and the mixture was stirred at room tem-
perature for 1 h. 100 mL of pure water was added to the flask to
dilute, followed by addition of 0.5 molLÀ1 dilute sulfuric acid,
which adjusted the solution to neutral. After extraction with di-
chloromethane (650 mL) the organic phase was dried over
MgSO4 overnight. The organic phase was filtered and evaporated
to dryness in vacuo. Separation by column chromatographic (pe-
troleum ether/ethyl acetate=1:1) gave 1.4 g of intermediate D
(Figure S8–4).
compounds into alkanes. The reaction can be divided into two
processes: saturation of the exocyclic double bond and furan
ring at low temperature; and the removal of hydroxyl groups
and the ring-opening of tetrahydrofurans at high temperature.
The reaction process is simple and the utilized catalysts are
commercially available. The catalytic effect of different metal
triflates, the effects of different solvents, and catalyst recycling
were studied separately. When using n-octane as solvent and
Hf(OTf)4 as metal triflate, the highest nonane yield was 92%.
Experimental Section
Preparation of alkanes
Materials
332 mg of raw materials A, 39 mg Hf(OTf)4, and 106 mg Pd/C were
charged in a 30 mL autoclave reactor. 10 mL of n-octane was
added to the reactor, and it was then filled with hydrogen to
5 MPa. Then, the reaction started at an elevated temperature pro-
gramme (608C for 16 h, 1808C for 20 h). After completion of the
reaction and cooling to room temperature, 10 mL of ethyl acetate
and the internal standard dodecane were added. The nonane yield
was detected by gas chromatography.
All the chemicals used in the experiments are commercially avail-
able. 5-HMF was generously gifted by Hefei Leaf Energy Biotech-
nology Co., Ltd. Hf(OTf)4 (98%), Pd/C (10%) from Alfa Aesar (China)
Chemicals Co., Ltd. La(OTf)3 (99%), Ce(OTf)3 (98%), Sm(OTf)3 (98%),
Yb(OTf)3 (98%), Sc(OTf)3 (99%), Fe(OTf)3 (95%), Al(OTf)3 (99%) by
Adamas Reagent Co., Ltd. n-Octane (98.0%), ethyl acetate (99.5%),
petroleum ether (60~908C), methanol (99.5%), acetone (99.5%),
tetrahydrofuran (99.0%), dichloromethane (99.5%), N,N-dimethyl-
formamide (99.5%), sodium hydroxide (96.0%), sodium borohy-
dride (96%), MgSO4 (98.0%) from Sinopharm Chemical Reagent
Co., Ltd. Dodecane (98%) by Energy Chemical. Silica gel (HG/
T2354–2010) from Branch Qingdao Haiyang Chemical Co., Ltd. Re-
agent water was purchased from Wahaha. The autoclave was pro-
vided by Anhui Kemi Machinery Technology Co., Ltd.
Reusability
After completion of the reaction, Pd/C was filtered off and washed
with ethyl acetate and then dried in vacuo. The filtrate was extract-
ed with 53 mL water, the aqueous phase was evaporated to dry-
ness in vacuo, and dried in vacuo. Then, the obtained Pd/C and
metal triflate were used to catalyze the next reaction round.
Preparation of material A (aldol condensation)[4–7,16]
10 g 5-HMF was added to a 500 mL round bottom flask, followed
by addition of 150 mL of acetone, and the 5-HMF was dissolved
with stirring at room temperature. After 5-HMF was completely dis-
solved, 50 mg NaOH powder was added to the flask, and the mix-
ture was stirred at room temperature for 10 h. After the reaction,
the material was filtered and dried over MgSO4 overnight. After fil-
tering again, the liquid was evaporated in vacuo, and separation
by column chromatography (petroleum ether/ethyl acetate=1:1)
Analysis methods
Substrates and products were detected by flame ionization detec-
tor gas chromatography (GC-FID, Shimadzu GC-2014), which used
Rtx-5 (30 m0.32 mm0.25 mm) and DM WAX (30 m0.32 mm
0.25 mm) as capillary column. Intermediates were detected by gas
chromatography–ion trap mass spectrometry (GC–MS, Thermo Sci-
entific ITQ1100), which used TR-5 MS (30 m0.25 mm0.25 mm) as
capillary column. The NMR spectra of compounds were detected
by using a Bruker nuclear magnetic resonance spectrometer
(400 MHz).
afforded 8.3 g raw material
ure S8–1).
A (Supporting Information, Fig-
Preparation of intermediates B, C, and D[8,17]
Acknowledgements
2 gA and 200 mg Pd/C were weighed in a 100 mL Schlenk flask.
50 mL of methanol was added to the flask and the contents were
mixed well. At 1 atm hydrogen pressure and 608C, the reaction
was carried out for 10 h. After the reaction was cooled to room
temperature, filtered, and the liquid evaporated in vacuo, separa-
tion by column chromatography (petroleum ether/ethyl acetate=
2:1) afforded 1.2 g of intermediate B (Figure S8–2).
2 gA and 200 mg Pd/C were weighed in a 100 mL autoclave reac-
tor. 50 mL of methanol was added to the reactor and the contents
were mixed well. At 5 MPa hydrogen pressure and room tempera-
ture, the reaction was carried out for 0.5 h. After completion of the
reaction, the mixture was filtered and the liquid evaporated in
vacuo. Separation by column chromatography (petroleum ether/
ethyl acetate=1:1) gave 1.6 g of intermediate C (Figure S8–3).
2 gA and 200 mg Pd/C were weighed in a 100 mL autoclave reac-
tor. 50 mL of methanol was added to the reactor and the contents
were mixed well. At 5 MPa hydrogen pressure and room tempera-
ture, the reaction was carried out for 0.5 h. After completion of the
This work was supported by the 973 Program (2012CB215305),
NSFC (21402181, 21325208, 21172209), CAS (KJCX2-EW-J02), CPSF
(2014M561835),
SRFDP
(20123402130008),
FRFCU
(WK2060190025, WK2060190033, WK3530000001), IPDFHCPST
(2014FXCX006) and PCSIRT. The authors thank the Hefei Leaf
Energy Biotechnology Co., Ltd. and Anhui Kemi Machinery Tech-
nology Co., Ltd. for free samples used in this study.
Keywords: alkanes · fuels · hydrodeoxygenation · renewable
resources · ring-opening reactions
ChemSusChem 2015, 8, 4250 – 4255
4254
ꢀ 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim