Is water a suitable solvent for the catalytic amination of alcohols?

Is water a suitable solvent for the catalytic amination of alcohols?

Green Chem., 2017, 19,2839-2845
DOI: 10.1039/C7GC00422B, Paper
Johannes Niemeier, Rebecca V. Engel, Marcus Rose
The catalytic aqueous-phase amination of biogenic alcohols with solid catalysts is reported for future development of renewable amine value-added chains.

Green Chemistry

Is water a suitable solvent for the catalytic amination of alcohols?

Abstract

The catalytic conversion of biomass and biogenic platform chemicals typically requires the use of solvents. Water is present already in the raw materials and in most cases a suitable solvent for the typically highly polar substrates. Hence, the development of novel catalytic routes for further processing would profit from the optimization of the reaction conditions in the aqueous phase mainly for energetic reasons by avoiding the initial water separation. Herein, we report the amination of biogenic alcohols in aqueous solutions using solid Ru-based catalysts and ammonia as a reactant. The influence of different support materials and bimetallic catalysts is investigated for the amination of isomannide as a biogenic diol. Most importantly, the transferability of the reaction conditions to various other primary and secondary alcohols is successfully proved. Hence, water appears to be a suitable solvent for the sustainable production of biogenic amines and offers great potential for further process development.

//////////

Advertisements

Selective hydrogenation of N-heterocyclic compounds using Ru nanocatalysts in ionic liquids

Selective hydrogenation of N-heterocyclic compounds using Ru nanocatalysts in ionic liquids

Green Chem., 2017, 19,2762-2767
DOI: 10.1039/C7GC00513J, Communication
Hannelore Konnerth, Martin H. G. Prechtl
N-Heterocyclic compounds have been tested in the selective hydrogenation catalysed by small 1-3 nm sized Ru nanoparticles (NPs) embedded in various imidazolium based ionic liquids (ILs).

http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC00513J?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

From the journal:

Green Chemistry

Selective hydrogenation of N-heterocyclic compounds using Ru nanocatalysts in ionic liquids

Abstract

N-Heterocyclic compounds have been tested in the selective hydrogenation catalysed by small 1–3 nm sized Ru nanoparticles (NPs) embedded in various imidazolium based ionic liquids (ILs). Particularly a diol-functionalised IL shows the best performance in the hydrogenation of quinoline to 1,2,3,4-tetrahydroquinoline (1THQ) with up to 99% selectivity.

///////////

Selective synthesis of dimethoxyethane via directly catalytic etherification of crude ethylene glycol

Selective synthesis of dimethoxyethane via directly catalytic etherification of crude ethylene glycol

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC00659D, Paper
Weiqiang Yu, Fang Lu, Qianqian Huang, Rui Lu, Shuai Chen, Jie Xu
A potential diesel fuel additive, dimethoxyethane, was highly selectively produced via etherification of crude ethylene glycol over SAPO-34

From the journal:

Green Chemistry

Selective synthesis of dimethoxyethane via directly catalytic etherification of crude ethylene glycol

Abstract

Etherification of ethylene glycol with methanol provides a sustainable route for the production of widely used dimethoxyethane; dimethoxyethane is a green solvent and reagent that is applied in batteries and used as a potential diesel fuel additive. SAPO-34 zeolite was found to be an efficient and highly selective catalyst for this etherification via a continuous flow experiment. It achieved up to 79.4% selectivity for dimethoxyethane with around 96.7% of conversion. The relationship of the catalyst’s structure and the dimethoxyethane selectivity was established via control experiments. The results indicated that the pore structure of SAPO-34 effectively limited the formation of 1,4-dioxane from activated ethylene glycol, enhanced the reaction of the activated methanol with ethylene glycol in priority, and thus resulted in high selectivity for the desired products. The continuous flow technology used in the study could efficiently promote the complete etherification of EG with methanol to maintain high selectivity for dimethoxyethane.

////////////

Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source

Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC01289F, Paper
Zhanhui Yang, Zhongpeng Zhu, Renshi Luo, Xiang Qiu, Ji-tian Liu, Jing-Kui Yang, Weiping Tang
A highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water, using formic acid as a reductant.

Green Chemistry

Iridium-catalyzed highly efficient chemoselective reduction of aldehydes in water using formic acid as the hydrogen source

Abstract

A water-soluble highly efficient iridium catalyst is developed for the chemoselective reduction of aldehydes to alcohols in water. The reduction uses formic acid as the traceless reducing agent and water as a solvent. It can be carried out in air without the need for inert atmosphere protection. The products can be purified by simple extraction without any column chromatography. The catalyst loading can be as low as 0.005 mol% and the turn-over frequency (TOF) is as high as 73 800 mol mol−1 h−1. A wide variety of functional groups, such as electron-rich or deficient (hetero)arenes and alkenes, alkyloxy groups, halogens, phenols, ketones, esters, carboxylic acids, cyano, and nitro groups, are all well tolerated, indicating excellent chemoselectivity.

http://pubs.rsc.org/en/Content/ArticleLanding/2017/GC/C7GC01289F?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Image result for 4-Methoxybenzyl alcohol

4-Methoxybenzyl alcohol (2a)2 . Yellowish oil. Yield: 273 mg, 99%.

1H NMR (400 MHz, CDCl3) δ 7.23 (d, J = 8.8 Hz, 2H), 6.85 (d, J = 8.7 Hz, 2H), 4.52 (s, 2H), 3.76 (s, 3H).

13C NMR (101 MHz, CDCl3) δ 159.07, 133.23, 128.63, 113.89, 64.73, 55.30, 55.26.

Zhanhui Yang

Zhanhui Yang

School of Pharmacy, University of Wisconsin–Madison, Madison, USA
E-mail:weiping.tang@wisc.edu

Organic Chemistry, Green Chemistry, Catalysis

PhD student
Beijing University of Chemical Technology
Organic Chemistry
Beijing, China
Image result for School of Pharmacy, University of Wisconsin–Madison, Madison, USA
School of Pharmacy, University of Wisconsin–Madison, Madison, USA
Image result for School of Pharmacy, University of Wisconsin–Madison, Madison, USA

Image result for School of Pharmacy, University of Wisconsin–Madison, Madison, USA

Image result for School of Pharmacy, University of Wisconsin–Madison, Madison, USA

4-Methoxybenzyl alcohol

//////////

Continuous niobium phosphate catalysed Skraup reaction for quinoline synthesis from solketal

 

STR1

Continuous niobium phosphate catalysed Skraup reaction for quinoline synthesis from solketal
Green Chem., 2017, Advance Article
DOI: 10.1039/C6GC03140D, Paper
Jing Jin, Sandro Guidi, Zahra Abada, Zacharias Amara, Maurizio Selva, Michael W. George, Martyn Poliakoff
Solketal is derived from the reaction of acetone with glycerol, a by-product of the biodiesel industry. We demonstrate the use of NbOPO4 as a catalyst for the conversion of solketal and anilines to quinolines

STR0

STR1

STR2

str3

str4

Synthesis of 4-(quinolin-6-yl methyl)aniline (6a)

The reaction was carried out accordingly to the general procedure. The purification of 4-(quinoline-6-yl methyl)aniline 6a was carried out with a gradient of polarity from 80:20 to 30:70 (v/v) of CyHex:AcOEt as eluent. 1H NMR (400 MHz, CDCl3) δ ppm: 8.85 (dd, J=4.3,1.7Hz, 1H), 8.07 (dd, J=8.3,1.8Hz, 1H), 8.01 (d, J=9.2Hz, 1H), 7.58–7.54 (m, 2H), 7.36 (dd, J=8.3,4.2Hz, 1H), 7.02 (d, J=8.3Hz, 2H), 6.67–6.63 (m, 2H), 4.06 (s, 2H). 13C NMR (100 MHz, CDCl3) δ ppm: 149.9, 147.3, 144.9, 140.7, 135.9, 131.4, 130.6, 130.1, 129.5, 128.5, 126.6, 121.2, 115.5, 41.2. HRMS-ESI for C16H15N2 [M+H]+ calculated 235.1235, found 235.1245.

Continuous niobium phosphate catalysed Skraup reaction for quinoline synthesis from solketal

Author affiliations

Abstract

Solketal is derived from the reaction of acetone with glycerol, a by-product of the biodiesel industry. We report here the continuous reaction of solketal with anilines over a solid acid niobium phosphate (NbP), for the continuous generation of quinolines in the well-established Skraup reaction. This study shows that NbP can catalyse all the stages of this multistep reaction at 250 °C and 10 MPa pressure, with a selectivity for quinoline of up to 60%. We found that the catalyst eventually deactivates, most probably via a combination of coking and reduction processes but nevertheless we show the promise of this approach. We demonstrate here the application of our approach to synthesize both mono- and bis-quinolines from the commodity chemical, 4,4′-methylenedianiline.

 

Cellulose acetate as a convenient intermediate for the preparation of 5-acetoxymethylfurfural from biomass

Cellulose acetate as a convenient intermediate for the preparation of 5-acetoxymethylfurfural from biomass

Author affiliations

Abstract

5-Acetoxymethylfurfural (AMF) is an important biomass derived platform chemical related to 5-hydroxymethylfurfural. Such furanic compounds can be produced via the hydrolysis of cellulose followed by dehydration of the resulting glucose units. However, the integration of these reactions in a single process remains technically challenging, and the direct use of monosaccharides is often preferred. In this work we report a new method for the synthesis of AMF based on the acetolysis of cellulose acetate in the presence of sulfuric acid. The strategy was optimized for both batch and continuous processing. Furthermore, cellulose acetate prepared by direct wood acetylation could be successfully applied as a precursor, proving the method as a robust solution for integrated biomass processing.

Cellulose acetate as a convenient intermediate for the preparation of 5-acetoxymethylfurfural from biomass

Green Chem., 2017, Advance Article

DOI: 10.1039/C7GC00975E, Communication
Open Access Open Access
Creative Commons Licence  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.
Llorenc Gavila, Davide Esposito
A new method for the synthesis of AMF based on the acetolysis of cellulose acetate is reported. Cellulose acetate prepared by wood acetylation can be applied as a precursor, offering possibilities for integrated biomass processing
Cellulose acetate synthesis from cellulose In a round bottom flask, cellulose (2 g, 12 mmol) was suspended in acetic acid (35 mL) and stirred for 1 hour at 55 °C. Thus, a mixture of acetic anhydride (10 mL, 105 mmol) and sulfuric acid (0.4 mL, 7.5 mmol) was slowly added, while the mixture was kept at 55 °C for 2 hours3 . The mixture was thus poured into cold water, the precipitate was filtered, washed and dried at 40 °C in a vacuum oven.
Cellulose acetate synthesis from pulp or wood In a round bottom flask, 2 g of wood or pulp were suspended in acetic acid (35 mL) and stirred for 1 hour at 55 °C. Thus, a mixture of acetic anhydride (10 mL, 105 mmol) and sulfuric acid (0.4 mL, 7.5 mmol) was slowly added, while the mixture was kept at 55 °C for 2 hours3 . The mixture was poured into cold water, the precipitate was filtered, washed and dried at 40 °C in a vacuum oven. In order to purify the cellulose acetate, the precipitate was stirred in dichloromethane (30 mL) at 30 °C for 1 hour; afterwards 2/3 of the solvent was evaporated with a rotary evaporator and poured into 20 mL of ethanol, the precipitate was washed with ethanol and dried at 40 °C in a vacuum oven.
General procedure for the acetolysis of cellulose acetate Solutions of cellulose acetate in acetic acid were prepared under the approximation that all cellulose acetate is composed of triacetylated anhydroglucose units (molar mass: 288 g/mol). The following molarities (mM) and the number of equivalents are therefore calculated with respect to triacetylated anhydroglucose units. Briefly, the corresponding amount of cellulose acetate to reach a final concentration of 5 g/L (17.4 mM) of cellulose acetate were dissolved in acetic acid and 35 mM of acetic anhydride (2 eq) and 35 mM of acid (2 eq) was added each run, unless otherwise stated. (The same procedure was adapted for non-acetylated cellulose [molar mass: 162 g/mol] as control experiment).

 

 

/////////////Cellulose acetate,  5-acetoxymethylfurfural,  biomass

Synthesis of ureas in the bio-alternative solvent Cyrene

Synthesis of ureas in the bio-alternative solvent Cyrene

Green Chem., 2017, Advance Article
DOI: 10.1039/C7GC00908A, Communication
Liam Mistry, Kopano Mapesa, Thomas W. Bousfield, Jason E. Camp
The bio-alternative solvent Cyrene was shown to be an alternative to toxic oil-derived solvents for the synthesis of ureas.
N-Phenylpyrrolidine-1-carboxamide (6a) 1
Method A: To a stirred solution of pyrrolidine (42 µL, 0.5 mmol) in Cyrene (0.5 mL, 1 M) at 0 °C was added phenyl isocyanate (4a, 55 µL, 0.5 mmol). The resultant mixture was allowed to warm to r.t. over 1 h. Water (5 mL) was added and the mixture was stirred for 30 min. The solvent was removed by Buchner filtration and the filtrate was washed with water (60 mL). The residue was dissolved in EtOAc (20 mL), dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure to give N-phenylpyrrolidine-1-carboxamide (6a, 76 mg, 80%), as a white solid.
Method B: To a stirred solution of pyrrolidine (42 µL, 0.5 mmol) in Cyrene (0.5 mL, 1 M) at 0 °C was added phenyl isocyanate (4a, 55 µL, 0.5 mmol). The resultant mixture was allowed to warm to r.t. over 1 h. Water (5 mL) was added and the mixture was stirred for 30 min. Water (25 mL) and EtOAc (25 mL) were added. The organic layer was dried over MgSO4 (10.0 g), filtered with the aid of EtOAc (10 mL). Silica gel (100 mg) was added and the solvent was removed under reduced pressure. The residue was purified by flash column chromatography on silica gel (100 g; EtOAc:hexane, 9:1) to to give N-phenylpyrrolidine-1- carboxamide (6a, 92 mg, 97%), as a white solid. mp. (o C) 133-134 [Lit.1 133-134];
IR (neat): 3292, 2971, 2871, 1639, 1532, 1438, 1373, 1239, 759 cm-1 ;
1 H NMR (CDCl3, 500 MHz) δ 1.92-1.94 (m, 4H), 3.42-3.45 (m, 4H), 6.29 (br. s, 1H), 6.98-7.01 (m, 1H), 7.24-2.28 (m, 2H), 7.40-7.42 (m, 2H);
13C NMR (CDCl3, 125 MHz) δ 25.5, 45.7, 119.5, 122.6, 128.7, 139.2, 153.9;
HRMS (ESI) m/z Calcd for [C11H15N2O] + 191.1184; found 191.1179.

Synthesis of ureas in the bio-alternative solvent Cyrene

Author affiliations

Abstract

Cyrene as a bio-alternative solvent: a highly efficient, waste minimizing protocol for the synthesis of ureas from isocyanates and secondary amines in the bio-available solvent Cyrene is reported. This method eliminated the use of toxic solvents, such as DMF, and established a simple work-up procedure for removal of the Cyrene, which led to a 28-fold increase in molar efficiency versus industrial standard protocols.

Graphical abstract: Synthesis of ureas in the bio-alternative solvent Cyrene
. References 1 Y. Wei, J. Liu, S. Lin, H. Ding, F. Liang and B. Zhao, Org. Lett., 2010, 12, 4220-4223.
////////////