scholarly journals Ammonia borane enabled upgrading of biomass derivatives at room temperature

2020 ◽  
Vol 22 (18) ◽  
pp. 5972-5977
Author(s):  
Wenfeng Zhao ◽  
Sebastian Meier ◽  
Song Yang ◽  
Anders Riisager
Keyword(s):  
Room Temperature ◽  
Value Added ◽  
Ammonia Borane ◽  
Efficient Catalyst ◽  
Free System ◽  
Mild Conditions ◽  
Catalyst Free ◽  
Value Added Products

An efficient catalyst-free system composed of ammonia borane in water or alcohol was developed to selectively convert biomass-derived feedstock into four value-added products under extremely mild conditions.

Michael Addition of Aryl Thiols to 3-(2,2,2-Trifluoroethylidene)Oxindoles under Catalyst-Free Conditions: The Rapid Synthesis of Sulfur-Containing Oxindole Derivatives

2018 ◽  
Vol 42 (4) ◽  
pp. 210-214
Author(s):  
Bo Chen ◽  
Jiaheng Lei ◽  
Junling Zhao
Keyword(s):  
Michael Addition ◽  
Room Temperature ◽  
Rapid Synthesis ◽  
Efficient Catalyst ◽  
Mild Conditions ◽  
Catalyst Free ◽  
Wide Range ◽  
High Yields ◽  
The Michael Addition ◽  
Sulfur Containing

A mild and efficient catalyst-free method for the rapid synthesis at room temperature of 3-thiomethylated oxindole derivatives has been achieved via the Michael addition of aryl thiols to ring and 1-substituted 3-(2,2,2-trifluoroethylidene)oxindoles in dichloromethane. The method was applicable to a wide range of thiols and variously substituted 3-(2,2,2-trifluoroethylidene)oxindoles under mild conditions as demonstrated by the synthesis in high yields with good diastereoselectivities of 30 3-thiomethylated oxindoles bearing a trifluoromethyl group.

Purification of Eucalyptus globulus water prehydrolyzates using the HiTAC process (high-temperature adsorption on activated charcoal)

Holzforschung ◽  
2011 ◽  
Vol 65 (4) ◽  
Author(s):  
Jenny Sabrina Gütsch ◽  
Herbert Sixta
Keyword(s):  
High Temperature ◽  
Room Temperature ◽  
Adsorption Process ◽  
Value Added ◽  
Sustainable Utilization ◽  
Pulp And Paper Mills ◽  
Paper Mills ◽  
Charcoal Adsorption ◽  
Increasing Temperature ◽  
Value Added Products

Abstract The implementation of biorefinery concepts into existing pulp and paper mills is a key step for a sustainable utilization of the natural resource wood. Water prehydrolysis of wood is an interesting process for the recovery of xylo-oligosaccharides and derivatives thereof, while at the same time cellulose is preserved to a large extent for subsequent dissolving pulp production. The recovery of value-added products out of autohydrolyzates is frequently hindered by extensive lignin precipitation, especially at high temperatures. In this study, a new high-temperature adsorption process (HiTAC process) was developed, where lignin is removed directly after the autohydrolysis, which enables further processing of the autohydrolyzates. The suitability of activated charcoals as a selective adsorbent for lignin under process-relevant conditions (150 and 170°C) has not been considered up to now, because former experiments showed decreasing efficiency of charcoal adsorption of lignin with increasing temperature in the range 20–80°C. In contrast to these results, we demonstrated that the adsorption of lignin at 170°C directly after autohydrolysis is even more efficient than after cooling the hydrolyzate to room temperature. The formation of lignin precipitation and incrustations can thus be efficiently prevented by the HiTAC process. The carbohydrates in the autohydrolysis liquor remain unaffected over a wide charcoal concentration range and can be further processed to yield valuable products.

scholarly journals A New Heterogeneous Catalyst Obtained via Supramolecular Decoration of Graphene with a Pd2+ Azamacrocyclic Complex

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2714 ◽  
Author(s):  
Matteo Savastano ◽  
Paloma Arranz-Mascarós ◽  
Maria Paz Clares ◽  
Rafael Cuesta ◽  
Maria Luz Godino-Salido ◽  
...  
Keyword(s):  
Heterogeneous Catalyst ◽  
Self Assembly ◽  
Room Temperature ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Assembly Process ◽  
Efficient Catalyst ◽  
Mild Conditions ◽  
Cross Coupling Reaction ◽  
Green Procedure

A new G-(H2L)-Pd heterogeneous catalyst has been prepared via a self-assembly process consisting in the spontaneous adsorption, in water at room temperature, of a macrocyclic H2L ligand on graphene (G) (G + H2L = G-(H2L)), followed by decoration of the macrocycle with Pd2+ ions (G-(H2L) + Pd2+ = G-(H2L)-Pd) under the same mild conditions. This supramolecular approach is a sustainable (green) procedure that preserves the special characteristics of graphene and furnishes an efficient catalyst for the Cu-free Sonogashira cross coupling reaction between iodobenzene and phenylacetylene. Indeed, G-(H2L)-Pd shows an excellent conversion (90%) of reactants into diphenylacetylene under mild conditions (50 °C, water, aerobic atmosphere, 14 h). The catalyst proved to be reusable for at least four cycles, although decreasing yields down to 50% were observed.

Uncatalyzed, on water oxygenative cleavage of inert C–N bond with concomitant 8,7-amino shift in 8-aminoquinoline derivatives

2019 ◽  
Vol 21 (7) ◽  
pp. 1735-1742 ◽  
Author(s):  
Vinayak Botla ◽  
NavyaSree Pilli ◽  
Chandrasekharam Malapaka
Keyword(s):  
Room Temperature ◽  
Efficient Catalyst ◽  
Catalyst Free ◽  
One Step

Oxygenative cleavage of an inert CAr–NH2 bond with concomitant 1,2 amine migration in 8-aminoquinoline derivatives is achieved through an efficient, catalyst free, one step synthesis of 8-benzyloxy, 7-aminoquinoline directly from 8-aminoquinoline in water at room temperature.

An integrated electrochemical process to convert lignin to value-added products under mild conditions

2016 ◽  
Vol 18 (18) ◽  
pp. 4999-5007 ◽  
Author(s):  
Serafin Stiefel ◽  
Annika Schmitz ◽  
Jens Peters ◽  
Davide Di Marino ◽  
Matthias Wessling
Keyword(s):  
Value Added ◽  
Electrochemical Process ◽  
Mild Conditions ◽  
Value Added Products

The controlled depolymerization of lignin is a promising approach for the generation of value-added compounds from biomass.

scholarly journals Synthesis of Ni2P/CdS and Pt/TiO2 nanocomposite for photoreduction of CO2 into methanol

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Penumaka Nagababu ◽  
Sehba Anjum Mumtaz Ahmed ◽  
Y. Taraka Prabhu ◽  
Ankush kularkar ◽  
Subhamoy Bhowmick ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Solar Energy ◽  
Physicochemical Properties ◽  
Noble Metal ◽  
Value Added ◽  
Spectroscopic Techniques ◽  
Efficient Catalyst ◽  
Metal Free ◽  
Value Added Products

AbstractIt is a great challenge to convert thermochemically stable CO2 into value-added products such as CH4, CH3OH, CO via utilizing solar energy. It is also a difficult task to develop an efficient catalyst for the reduction of CO2. We have designed and synthesized noble metal-free photocatalytic nanostructure Ni2P/CdS and Pt/TiO2 for conversion of CO2 to methanol in the presence of sacrificial donor triethylamine (TEA) and hydrogen peroxide. The synthesised catalysts physicochemical properties were studied by using several spectroscopic techniques like; XRD, UV-DRS, XPS, TEM, SEM and PL. Quantification of methanol by GC–MS showed encouraging results of 1424.8 and 2843 μmol g−1 of catalyst for Pt/TiO2 and 5 wt% Ni2P/CdS composites, respectively. Thus, Ni2P/CdS is a promising catalyst with higher productivity and significant selectivity than in-vogue catalysts.

Efficient Catalyst-Free Trans Sulfonamidation/Sulfonamide Metathesis under Mild Conditions

2018 ◽  
Vol 3 (8) ◽  
pp. 2306-2310 ◽  
Author(s):  
Rajagopal Ramkumar ◽  
Srinivasan Chandrasekaran
Keyword(s):  
Efficient Catalyst ◽  
Mild Conditions ◽  
Catalyst Free

Efficient chemical fixation of CO2 from direct air under environment-friendly co-catalyst and solvent-free ambient conditions

2021 ◽  
Author(s):  
Rajesh Das ◽  
THIRUMAVALAVAN EZHIL ◽  
Athulya S. Palakkal ◽  
Devaraj Muthukumar ◽  
Renjith S. Pillai ◽  
...  
Keyword(s):  
Environmental Remediation ◽  
Value Added ◽  
Solvent Free ◽  
Chemical Fixation ◽  
Ambient Conditions ◽  
Energy Sustainability ◽  
Environment Friendly ◽  
Co Catalyst ◽  
Mild Conditions ◽  
Value Added Products

The capture and conversion of CO2 from direct air into value-added products under mild conditions represents a promising step towards environmental remediation and energy sustainability. Consequently, herein, we report application...

Catalyst-free amidation of aldehyde with amine under mild conditions

2015 ◽  
Vol 39 (8) ◽  
pp. 5912-5915 ◽  
Author(s):  
Hongyin Yang ◽  
Wenjian Hu ◽  
Shengjue Deng ◽  
Tiantian Wu ◽  
Haiman Cen ◽  
...  
Keyword(s):  
Direct Synthesis ◽  
One Pot ◽  
Efficient Catalyst ◽  
Mild Conditions ◽  
Catalyst Free ◽  
Highly Efficient

A highly efficient, catalyst-free and one-pot procedure for the direct synthesis of amides from aldehydes and amines under mild conditions has been developed.

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