Catalyst-free thiolation of indoles with sulfonyl hydrazides for the synthesis of 3-sulfenylindoles in water

 

Catalyst-free thiolation of indoles with sulfonyl hydrazides for the synthesis of 3-sulfenylindoles in water

Green Chem., 2016, Advance Article
DOI: 10.1039/C6GC00313C, Communication

Yu Yang, Sheng Zhang, Lin Tang, Yanbin Hu, Zhenggen Zha, Zhiyong Wang
A water promoted thiolation of indoles with sulfonyl hydrazides has been developed under mild conditions in water.

http://pubs.rsc.org/en/Content/ArticleLanding/2016/GC/C6GC00313C?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

 

A catalyst-free thiolation of indoles with sulfonyl hydrazides was efficiently developed in water under mild conditions without any ligand or additive. The reaction provided a variety of 3-sulfenylindoles with good to excellent yields and the only by-products were nitrogen and water.

 

[1] F.-L. Yang, X.-T. Ma and S.-K. Tian, Chem. Eur. J., 2012, 18, 1582

 

 

 

 

 

Catalyst-free thiolation of indoles with sulfonyl hydrazides for the synthesis of 3-sulfenylindoles in water

Yu Yang,^a   Sheng Zhang,^a   Lin Tang,^a   Yanbin Hu,^a  Zhenggen Zha^a and   Zhiyong Wang*^a  

 

*Corresponding authors

^aHefei National Laboratory for Physical Sciences at Microscale, CAS Key Laboratory of Soft Matter Chemistry and Department of Chemistry & Collaborative Innovation Center of Suzhou Nano Science and Technology, University of Science and Technology of China, Hefei, P. R. China
E-mail: zwang3@ustc.edu.cn
Fax: (+86) 551-360-3185

Green Chem., 2016, Advance Article

DOI: 10.1039/C6GC00313C

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Pd(II) pincer type complex catalyzed tandem C-H and N-H activation of acetanilide in aqueous media: a concise access to functionalized carbazoles in a single step

 

 

Pd(II) pincer type complex catalyzed tandem C-H and N-H activation of acetanilide in aqueous media: a concise access to functionalized carbazoles in a single step

Green Chem., 2016, Advance Article
DOI: 10.1039/C5GC02937F, Paper

Vignesh Arumugam, Werner Kaminsky, Dharmaraj Nallasamy
NNO Pincer type Pd(II) complex catalyzed one-pot synthesis of N-acetylcarbazoles in aqueous media is presented.

http://pubs.rsc.org/en/Content/ArticleLanding/2016/GC/C5GC02937F?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

One-pot, tandem C–H and N–H activation of acetanilides with aryl boronic acids to realize functionalized carbazoles was conveniently performed under aerobic conditions using a novelNNO pincer type Pd(II) complex [Pd(L)Cl] (where L = nicotinic acid (phenyl-pyridin-2-yl-methylene)-hydrazide or furan-2-carboxylic acid (phenyl-pyridin-2-yl-methylene)-hydrazide) as a catalyst in neat water and a very low (0.01 mol%) amount of catalyst. It is worth noting that recyclability up to six consecutive runs and column chromatography free isolation of the title heterocycles in an excellent yield are achieved.

 

Pd(II) pincer type complex catalyzed tandem C–H and N–H activation of acetanilide in aqueous media: a concise access to functionalized carbazoles in a single step

Vignesh Arumugam,^a   Werner Kaminsky^b and  Dharmaraj Nallasamy*^a  

 

 

*Corresponding authors

^aInorganic & Nanomaterials Research Laboratory, Department of Chemistry, Bharathiar University, Coimbatore 641 046, India
E-mail: dharmaraj@buc.edu.in
Web: http://ndharmaraj.wix.com/inrl
Fax: +91 4222422387
Tel: +91 4222428316

^bDepartment of Chemistry, University of Washington, Seattle, USA

Green Chem., 2016, Advance Article

DOI: 10.1039/C5GC02937F

 

One-pot, tandem C–H and N–H activation of acetanilides with aryl boronic acids to realize functionalized carbazoles was conveniently performed under aerobic conditions using a novelNNO pincer type Pd(II) complex [Pd(L)Cl] (where L = nicotinic acid (phenyl-pyridin-2-yl-methylene)-hydrazide or furan-2-carboxylic acid (phenyl-pyridin-2-yl-methylene)-hydrazide) as a catalyst in neat water and a very low (0.01 mol%) amount of catalyst. It is worth noting that recyclability up to six consecutive runs and column chromatography free isolation of the title heterocycles in an excellent yield are achieved.

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Synthesis of vinyl ethers of alcohols using calcium carbide under superbasic catalytic conditions (KOH/DMSO)

Green Chem., 2016, Advance Article
DOI: 10.1039/C5GC02977E, Communication

Ryosuke Matake, Yusuke Adachi, Hiroshi Matsubara
A convenient preparation of vinyl ethers from alcohols with calcium carbide was developed. This protocol is an alternative to the Favorskii-Reppe reaction without any high pressure device.

Synthesis of vinyl ethers of alcohols using calcium carbide under superbasic catalytic conditions (KOH/DMSO)

 LINK       http://pubs.rsc.org/en/Content/ArticleLanding/2016/GC/C5GC02977E?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

 Vinyl ethers are important and useful synthetic building blocks. Using a test tube with a screw cap, a convenient preparation of vinyl ethers from alcohols with calcium carbide under superbasic catalytic conditions (KOH/DMSO) was developed. The vinylation of primary and secondary alcohols was successfully achieved, affording the desired products in good yields. The gram-scale preparation of a vinyl ether was also demonstrated. In this reaction, calcium carbide acts as an acetylene source, constituting a safer alternative to acetylene gas.

 F. de Nanteuil, E. Serrano, D. Perrotta and J. Waser, J. Am. Chem. Soc., 2014, 136, 6239.


1H NMR

1H NMR PREDICT using nmrdb , signals may vary , use your discretion to understand sequence

13C NMR

13 C NMR PREDICT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Synthesis of vinyl ethers of alcohols using calcium carbide under superbasic catalytic conditions (KOH/DMSO)

Ryosuke Matake,^a   Yusuke Adachi^a and   Hiroshi Matsubara*^a  

*

Corresponding authors

^a

Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Sakai, Japan
E-mail: matsu@c.s.osakafu-u.ac.jp

Green Chem., 2016, Advance Article

DOI: 10.1039/C5GC02977E ////////////////////

cis (Z) jasmone

.

 cis (Z) jasmone 

(Can. J. Chem. 1978, Vol 56, p2301)

e.g. How might we attempt to make Z jasmone – an important constituent of many perfumes?

In fact one synthesis uses the following as carbon sources:

It is not clear from this however, how the chemistry might be done!  Therefore just being given the starting materials is not sufficient to help plan a synthesis.
Note the importance of CCBFR.

We need a logical planning method.

Retrosynthetic Analysis (The Disconnection Approach)

Originated by E.J. Corey (Nobel Prize 1990)               p169 – 172

                                                                                    p259 – 260

                                                                                    p354 – 359

Interesting compound, Spoked-wheel macrocycles

.

 

• Chemical Formula: C₇₇₄H₉₉₆N₁₈O₃₆Si₁₂
• Molecular Weight: 11465.32
• Elemental Analysis: C, 81.08; H, 8.76; N, 2.20; O, 5.02; Si, 2.94

 4-({2-[4-(2-{9-[4-(4-{2-[2,5-Bis(octyloxy)-4-(2-{4-[pentakis({4-[2-(4-{2-[4-(4-{2,7-bis[2-(4-{2-[(3-cyanopropyl)bis(propan-2-yl)silyl]ethynyl}-2,5-bis(octyloxy)phenyl)ethynyl]-9H-carbazol-9-yl}phenyl)phenyl]ethynyl}-2,5-bis(octyloxy)phenyl)ethynyl]phenyl})phenyl]phenyl}ethynyl)phenyl]ethynyl}phenyl)phenyl]-7-[2-(4-{2-[(3-cyanopropyl)bis(propan-2-yl)silyl]ethynyl}-2,5-bis(octyloxy)phenyl)ethynyl]-9H-carbazol-2-yl}ethynyl)-2,5-bis(octyloxy)phenyl]ethynyl}bis(propan-2-yl)silyl)butanenitrile

Compound 7

From Fluctuating exciton localization in giant π-conjugated spoked-wheel macrocycles

• A. Vikas Aggarwal,
• Alexander Thiessen,
• Alissa Idelson,
• Daniel Kalle,
• Dominik Würsch,
• Thomas Stangl,
• Florian Steiner,
• Stefan-S. Jester,
• Jan Vogelsang,
• Sigurd Höger
• & John M. Lupton

Nature Chemistry5,964–970(2013)

doi:10.1038/nchem.1758

Supplementary Information

 

C774H996N18O36Si12
Name compound: 4-({2-[4-(2-{9-[4-(4-{2-[2,5-Bis(octyloxy)-4-(2-{4-[pentakis({4-[2-(4-{2-[4-(4-{2,7-bis[2-(4-{2-[(3-cyanopropyl)bis(propan-2-yl)silyl]ethynyl}-2,5-bis(octyloxy)phenyl)ethynyl]-9H-carbazol-9-yl}phenyl)phenyl]ethynyl}-2,5-bis(octyloxy)phenyl)ethynyl]phenyl})phenyl]phenyl}ethynyl)phenyl]ethynyl}phenyl)phenyl]-7-[2-(4-{2-[(3-cyanopropyl)bis(propan-2-yl)silyl]ethynyl}-2,5-bis(octyloxy)phenyl)ethynyl]-9H-carbazol-2-yl}ethynyl)-2,5-bis(octyloxy)phenyl]ethynyl}bis(propan-2-yl)silyl)butanenitrile.

https://www.instagram.com/p/BBMfA4bBkvZY9QhsJV6ff6khLjUE6F9MqBqRu40/

• Synthetic Procedure: See article for the definitive version of this procedure and for full experimental details.6 (19.0 mg, 14.7 µmol), CuI (3.4 mg, 17.7 µmol), Pd₂dba₃(4.0 mg, 4.4 µmol), and tri(t‑butyl)phosphine (6.0 mg, 29.5 µmol) were mixed in a microwave tube and sealed with a septum. In parallel, a solution of 5 (241.7 mg, 132.6 µmol) in piperidine (2 mL) was purged with argon for 1 h. Then the latter was transferred to the microwave tube and the mixture was heated at 120 °C for 16 min in a microwave instrument (max. power: 300 W). After cooling to r.t., the tube was opened and the reaction mixture was diluted with MTBE. The organic phase was washed with aq. H₂SO₄ (10 %) and brine. It was dried over MgSO₄ and the solvent was removed under reduced pressure. The residue was purified by column chromatography (CH:DCM = 65:35 ‑ 68:32), and 7 (126 mg, 10.9 µmol, 74 %) was obtained as a yellow solid. ¹H NMR (500 MHz, CDCl₃, 298 K) δ [ppm] = 8.09 (d, ³J_H,H = 8.2 Hz, 12 H), 7.87 (d, ³J_H,H = 8.5 Hz, 12 H), 7.76 – 7.60 (m, 48 H), 7.55 – 7.46 (m, 12 H), 7.16 (d, ³J_H,H = 8.0 Hz, 12 H), 7.03 (s, 6 H), 7.02 (s, 6 H), 6.96 (s, 12 H), 6.93 (s, 12 H), 6.86 (d, ³J_H,H = 8.1 Hz, 12 H), 4.10 – 3.99 (m, 48 H), 3.99 – 3.90 (m, 24 H), 2.42 (t, ³J_H,H = 7.0 Hz, 24 H), 1.95 – 1.72 (m, 96 H), 1.62 – 1.16 (m, 360 H), 1.15 – 0.97 (m, 168 H), 0.97 – 0.76 (m, 132 H); ¹H NMR (500 MHz, CD₂Cl₂, 298 K) δ [ppm] = 8.14 (d, ³J_H,H = 8.1 Hz, 12 H), 7.92 (d, ³J_H,H = 8.5 Hz, 12 H), 7.79 – 7.66 (m, 36 H), 7.64 (s, 12 H), 7.54 – 7.44 (m, 12 H), 7.20 (d, ³J_H,H = 8.2 Hz, 12 H), 7.05 (s, 6 H), 7.02 (s, 6 H), 6.99 (s, 12 H), 6.97 – 6.93 (m, 24 H), 4.08 – 3.98 (m, 48 H), 3.98 – 3.92 (m, 24 H), 2.41 (t, ³J_H,H = 7.0 Hz, 24 H), 1.96 – 1.71 (m, 96 H), 1.65 – 1.17 (m, 360 H), 1.17 – 0.99 (m, 168 H), 0.99 – 0.76 (m, 132 H); ¹³C NMR (126 MHz, CDCl₃, 298 K) δ [ppm] = 154.78, 154.06, 153.94, 153.79, 141.60, 140.49, 140.41, 140.10, 136.79, 132.63, 131.73, 130.90, 128.94, 127.99, 127.36, 124.58, 123.55, 123.50, 121.54, 121.26, 120.86, 120.21, 118.04, 117.40, 117.28, 116.51, 114.96, 114.65, 114.07, 113.58, 113.47, 104.31, 96.51, 95.56, 94.91, 87.61, 86.62, 70.16, 70.04, 70.00, 69.56, 32.27, 32.25, 32.24, 32.18, 29.82, 29.79, 29.75, 29.73, 29.71, 29.68, 26.52, 26.42, 26.40, 23.14, 23.13, 23.09, 23.08, 21.70, 21.17, 18.65, 18.41, 14.63, 14.57, 14.52, 14.50, 12.20, 10.04; ¹³C NMR (126 MHz, CD₂Cl₂, 298 K) δ [ppm] = 154.88, 154.20, 154.11, 153.93, 141.87, 140.89, 140.63, 140.50, 140.40, 136.88, 132.68, 132.04, 130.83, 129.11, 128.15, 127.61, 124.49, 123.69, 123.50, 121.66, 121.44, 121.10, 120.32, 117.99, 117.47, 117.28, 116.70, 114.90, 114.62, 114.20, 113.84, 113.62, 104.31, 96.45, 95.91, 95.35, 94.94, 87.71, 86.85, 86.80, 70.22, 70.14, 69.82, 32.44, 32.35, 29.97, 29.93, 29.90, 29.88, 29.83, 29.83, 26.69, 26.67, 26.58, 26.54, 23.31, 23.29, 23.25, 23.24, 21.89, 21.22, 18.56, 18.32, 14.57, 14.50, 14.45, 14.43, 12.35, 10.14;MS (MALDI-TOF, DCTB) (calcd. for C₇₇₄H₉₉₆N₁₈O₃₆Si₁₂ monoisotopic: 11455.39, distr. max.: 11465.32): m/z11965.9 [M+2*DCTB]⁺, 11716.6 [M+DCTB]⁺, 11465.3 [M]⁺, 5856.8 [M+DCTB]²⁺, 5733.5 [M]²⁺; GPC (in THF vs. PS): M_p = 11580 g mol^-1.

Soheil Zabihi
 http://www.nature.com/nchem/journal/v5/n11/compound/nchem.1758_comp7.html
http://www.nature.com/nchem/journal/v5/n11/extref/nchem.1758-s1.pdf
http://www.nature.com/nchem/journal/v5/n11/extref/nchem.1758-s1.pdf

Affiliations

1. Kekulé-Institut für Organische Chemie und Biochemie der Universität Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany

   • A. Vikas Aggarwal,
   • Alissa Idelson,
   • Daniel Kalle,
   • Stefan-S. Jester &
   • Sigurd Höger

2. Department of Physics and Astronomy, University of Utah, Salt Lake City, Utah 84112, USA

   • Alexander Thiessen &
   • John M. Lupton

3. Institut für Experimentelle und Angewandte Physik, Universität Regensburg, Universitätsstrasse 31, D-93040 Regensburg, Germany

   • Dominik Würsch,
   • Thomas Stangl,
   • Florian Steiner,
   • Jan Vogelsang &
   • John M. Lupton

///////////
SMILES: CCCCCCCCOC(C=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C(OCCCCCCCC)=C1)=C1C#CC2=CC3=C(C=C2)C4=C(C=C(C#CC5=C(OCCCCCCCC)C=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C(OCCCCCCCC)=C5)C=C4)N3C(C=C6)=CC=C6C(C=C7)=CC=C7C#CC(C=C8OCCCCCCCC)=C(OCCCCCCCC)C=C8C#CC(C=C9)=CC=C9C%10=C(C%11=CC=C(C#CC%12=C(OCCCCCCCC)C=C(C#CC%13=CC=C(C%14=CC=C(N%15C(C=C(C#CC%16=CC(OCCCCCCCC)=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C=C%16OCCCCCCCC)C=C%17)=C%17C%18=C%15C=C(C#CC%19=CC(OCCCCCCCC)=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C=C%19OCCCCCCCC)C=C%18)C=C%14)C=C%13)C(OCCCCCCCC)=C%12)C=C%11)C(C%20=CC=C(C#CC%21=C(OCCCCCCCC)C=C(C#CC%22=CC=C(C%23=CC=C(N%24C(C=C(C#CC%25=C(OCCCCCCCC)C=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C(OCCCCCCCC)=C%25)C=C%26)=C%26C%27=C%24C=C(C#CC%28=C(OCCCCCCCC)C=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C(OCCCCCCCC)=C%28)C=C%27)C=C%23)C=C%22)C(OCCCCCCCC)=C%21)C=C%20)=C(C%29=CC=C(C#CC%30=CC(OCCCCCCCC)=C(C#CC%31=CC=C(C%32=CC=C(N%33C(C=C(C#CC%34=C(OCCCCCCCC)C=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C(OCCCCCCCC)=C%34)C=C%35)=C%35C%36=C%33C=C(C#CC%37=C(OCCCCCCCC)C=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C(OCCCCCCCC)=C%37)C=C%36)C=C%32)C=C%31)C=C%30OCCCCCCCC)C=C%29)C(C%38=CC=C(C#CC%39=C(OCCCCCCCC)C=C(C#CC%40=CC=C(C%41=CC=C(N%42C(C=C(C#CC%43=CC(OCCCCCCCC)=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C=C%43OCCCCCCCC)C=C%44)=C%44C%45=C%42C=C(C#CC%46=CC(OCCCCCCCC)=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C=C%46OCCCCCCCC)C=C%45)C=C%41)C=C%40)C(OCCCCCCCC)=C%39)C=C%38)=C%10C%47=CC=C(C#CC%48=C(OCCCCCCCC)C=C(C#CC%49=CC=C(C%50=CC=C(N%51C(C=C(C#CC%52=C(OCCCCCCCC)C=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C(OCCCCCCCC)=C%52)C=C%53)=C%53C%54=C%51C=C(C#CC%55=CC(OCCCCCCCC)=C(C#C[Si](C(C)C)(C(C)C)CCCC#N)C=C%55OCCCCCCCC)C=C%54)C=C%50)C=C%49)C(OCCCCCCCC)=C%48)C=C%47

Scheme 1. Diene-Transmissive Diels–Alder Cycloaddition Sequences of [3]- and [4]Dendralene with the Prototypical Olefinic Dienophile

The first synthesis of all five possible monomethylated [4]dendralenes has been achieved via two distinct synthetic strategies. The Diels–Alder chemistry of these new dendralenes (as multidienes) with an electron poor dienophile, N-methylmaleimide (NMM), has been studied. Thus, simply upon mixing the dendralene and an excess of dienophile at ambient temperature in a common solvent, sequences of cycloadditions result in the rapid generation of complex multicyclic products. Distinct product distributions are obtained with differently substituted dendralenes, demonstrating that dendralene substitution influences the pathway followed, when a matrix of mechanistic possibilities exists. Dendralene site selectivities are traced to electronic, steric and conformational effects, thereby allowing predictive tools for applications of substituted dendralenes in future synthetic endeavors.

Scheme 2. Diene-Transmissive Diels–Alder Cycloaddition Sequences of [4]Dendralene (1) with the Dienophile N-Methylmaleimide (NMM)

Scheme 3. Syntheses of the Five Mono-Methyl-Substituted-[4]Dendralenes

3 Diels-Alder reactions in 1 go

 
FROM https://naturalproductman.wordpress.com/2016/01/29/11137/

Tris-adduct 36

An analytic sample of 36 was obtained by recrystallization from EtOAc/hexane to give colorless needles, mp 255–257 °C; R_f 0.20 (EtOAc, 100%);  

 

¹H NMR (300 MHz, CDCl₃) δ 3.22 (dd, J = 8.6, 5.9 Hz, 1H), 3.19–3.07 (m, 3H), 3.04–2.91 (m, 5H), 2.90 (s, 6H), 2.86 (s, 3H), 2.65 (ddd, J = 14.1, 13.4, 5.4 Hz, 1H), 2.35 (ddd, J = 14.3, 5.0, 2.5 Hz, 1H), 2.16–2.05 (m, 2H), 2.03–1.91 (m, 1H), 1.85–1.74 (m, 1H), 1.54 (d, J = 6.8 Hz, 3H) ppm;  

 

¹³C NMR (75 MHz, CDCl₃) δ 179.7 (C), 178.5 (C), 178.4 (C), 178.3 (C), 177.0 (C), 176.6 (C), 130.8 (C), 130.8 (C), 44.4 (CH), 43.4 (CH), 40.8 (CH), 40.6 (CH), 40.3 (CH), 39.2 (CH), 38.8 (CH), 33.7 (CH), 29.0 (CH), 25.0 (CH₃), 24.9 (CH₃), 24.8 (CH₃), 24.7 (CH₂), 24.4 (CH₂), 23.1 (CH₂), 16.5 (CH₃) ppm; 

 

 

IR (KBr disc) ν_max = 2961, 2948, 2842, 1770, 1695, 1435, 1383, 1286 cm^–1; 

 

 

LRMS (70 eV, EI) m/z (%) 453 ([M]^+•, 100%), 438 (7), 342 (33), 256 (14), 112 (39); 

 

 

HRMS calc for C₂₄H₂₇N₃O₆ [M]^+• 453.1900, found 453.1905.

Synthesis and Diels–Alder Reactivity of Substituted [4]Dendralenes

Mehmet F. Saglam^†, Ali R. Alborzi^†, Alan D. Payne^†, Anthony C. Willis^†, Michael N. Paddon-Row^‡, and Michael S. Sherburn^*†

^† Research School of Chemistry, The Australian National University, Canberra, ACT 2601, Australia

^‡ School of Chemistry, The University of New South Wales, Sydney, NSW 2052, Australia

J. Org. Chem., Article ASAP

DOI: 10.1021/acs.joc.5b02583

Publication Date (Web): January 12, 2016

Copyright © 2016 American Chemical Society

*E-mail: michael.sherburn@anu.edu.au.

 http://pubs.acs.org/doi/full/10.1021/acs.joc.5b02583

ACS Editors' Choice - This is an open access article published under an ACS AuthorChoice License, which permits copying and redistribution of the article or any adaptations for non-commercial purposes.

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Reductive amination of furfural to furfurylamine using aqueous ammonia solution and molecular hydrogen: an environmentally friendly approach

Green Chem., 2016, 18,487-496
DOI: 10.1039/C5GC01352F, Paper

Maya Chatterjee, Takayuki Ishizaka, Hajime Kawanami
An efficient process was developed to obtain furfurylamine with very high yield ([similar]92%) through the reductive amination of furfural under a mild reaction condition.

Reductive amination of furfural to furfurylamine using aqueous ammonia solution and molecular hydrogen: an environmentally friendly approach

 http://pubs.rsc.org/en/Content/ArticleLanding/2016/GC/C5GC01352F?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

A simple and highly efficient method was developed for the transformation of furfural (a biomass derived aldehyde) to furfurylamine by reductive amination using an aqueous solution of ammonia and molecular hydrogen as an amine source and a reducing agent, respectively. By choosing a suitable catalyst, such as Rh/Al₂O₃, and reaction conditions, a very high selectivity of furfurylamine (∼92%) can be achieved within the reaction time of 2 h at 80 °C. A detailed analysis of the reaction system sheds some light on the reaction pathway and provides an understanding about each elementary step. The reaction was believed to proceed via an imine pathway although no such intermediate was detected because of the highly reactive nature. Optimization of different reaction parameters such as hydrogen pressure, temperature and substrate/ammonia mole ratio is shown to be critical to achieve high selectivity of furfurylamine. Time-dependent reaction profiles suggested that a Schiff base type intermediate was in the detectable range, which offers indirect evidence of the formation of imine. Competitive hydrogenation and amination of an aldehyde group were strongly dictated by the nature of the metal used. The studied protocol represents an environmentally benign process for amine synthesis, which can be effectively extended to the other aldehydes also. The studied catalyst could be recycled successfully without any significant loss of catalytic activity.

Reductive amination of furfural to furfurylamine using aqueous ammonia solution and molecular hydrogen: an environmentally friendly approach

Maya Chatterjee,*^a   Takayuki Ishizaka^a and  Hajime Kawanami*^ab  

*

Corresponding authors

^a

Microflow Chemistry Group, Research Institute for Chemical Process Technology, AIST Tohoku, 4-2-1, Nigatake, Miyagino-ku, Japan 
E-mail: c-maya@aist.go.jp, h-kawanami@aist.go.jp
Fax: +81 22 237 5388 
Tel: +81 22 237 5213

^b

CREST, Japan Science and Technology (JST), 4-1-8, Honcho, Kawaguchi, Japan

Green Chem., 2016,18, 487-496

DOI: 10.1039/C5GC01352F     /////////////