Well‐Defined [Cp*Co(N,O)I]‐Catalysts for Site‐Selective Intramolecular C−H Amidation DOI

Pardeep Dahiya,

Ankita Sarkar, Basker Sundararaju

et al.

Advanced Synthesis & Catalysis, Journal Year: 2022, Volume and Issue: 364(15), P. 2642 - 2647

Published: June 23, 2022

Abstract We present an efficient method for forming C−N bonds via intramolecular amidation catalyzed by well‐defined Cp*Co(N,O)I complexes. The reaction has been operate under mild conditions and produced a regioselective product without the use of bulky counter anion or expensive fluorinated solvents. Cp*Co(N,O)‐I catalyst is very effective benzylic, tertiary, internal C( sp 3 )−H bond amidation, but ineffective 2 amidation. magnified image

Language: Английский

Metal-catalyzed plastic depolymerization DOI Creative Commons
Kishor V. Khopade, Samir H. Chikkali, Nagaraju Barsu

et al.

Cell Reports Physical Science, Journal Year: 2023, Volume and Issue: 4(5), P. 101341 - 101341

Published: March 29, 2023

Polymers have become an indispensable part of our daily lives, and today we produce around 370 MT plastic per year. Only about 20% it is being recycled, the rest, 80%, unleashed into environment without appropriate treatment. This calls forth evaluation strategies available for mitigating menace "after-use" waste. Various approaches evolved over a decade are at different levels development. Plastic depolymerization upcycling considered some most prominent long-term solutions. The metal-catalyzed waste to chemical feedstocks has emerged as one promising ways address global pollution. Therefore, this review aims examine methods, notify recent progress, pinpoint current gaps, gauge potential strategy. Both homogeneous heterogeneous catalysts been reported depolymerize various polymers last decade. Considerable advances in metal-mediated polyolefins, polyesters, polycarbonates, polyurethanes, polyamides, polyethers. above produces monomers or intermediates, which can be used again polymerization thus brings back circularity. overview debates usage high temperatures, sophisticated ligands, expensive metals, stoichiometric reagents, etc., depolymerization. Thus, summarizes understanding fundamental science depolymerization, remaining scientific challenges, opportunities.

Language: Английский

Citations

46
Catalytic Hydrogenation of Polyurethanes to Base Chemicals: From Model Systems to Commercial and End-of-Life Polyurethane Materials DOI Creative Commons
Laurynas Gausas, Steffan K. Kristensen, Hongwei Sun

et al.

JACS Au, Journal Year: 2021, Volume and Issue: 1(4), P. 517 - 524

Published: April 6, 2021

Polyurethane (PU) is a highly valued polymer prepared from diisocyanates and polyols, it used in everyday products, such as shoe soles, mattresses, insulation materials, but also for the construction of sophisticated parts medical devices, wind turbine blades, aircrafts, spacecrafts, to name few. As PU most commonly thermoset composed cross-linked structures, its recycling complicated inefficient, leading increasing waste accumulating every year. Catalytic hydrogenation represents an atom-efficient means deconstruction polyurethanes, so far identification efficient catalyst disassembly real-life end-of-life samples has not been demonstrated. In this work, we reveal that commercially available catalyst, Ir-iPrMACHO, under 30 bar H2 150–180 °C, general effective four cornerstones PU: flexible solid, foamed, rigid isolation aromatic amines polyol fraction. For first time, variety commercial including examples foams, inline skating wheels, deconstructed into two fractions. Most desirable, our reaction conditions include use isopropyl alcohol representative green solvent. It speculated partial glycolysis at surface particles taking place solvent temperatures presence catalytic amounts base. more solubilized fragments becomes possible. isolated anilines are precursors original isocyanate building blocks, methods their conversion well-known, work reported paper provides realistic indication potential circular plastic economy solution PU. Preliminary experiments were undertaken applying Mn-iPrMACHO foam. Although successful, forcing required than those when Ir-iPrMACHO.

Language: Английский

Citations

77
Reductive depolymerization as an efficient methodology for the conversion of plastic waste into value-added compounds DOI
Ana C. Fernandes

Green Chemistry, Journal Year: 2021, Volume and Issue: 23(19), P. 7330 - 7360

Published: Jan. 1, 2021

Reductive depolymerization allows the valorization of polyester, polycarbonate and polyamide waste in a wide variety value-added compounds with good yields

Language: Английский

Citations

77
Catalytic hydroconversion processes for upcycling plastic waste to fuels and chemicals DOI

Junde Wei,

Jieyi Liu,

Weihao Zeng

et al.

Catalysis Science & Technology, Journal Year: 2022, Volume and Issue: 13(5), P. 1258 - 1280

Published: Dec. 15, 2022

This review provides an overview of catalytic hydroconversion processes including hydrocracking, hydrogenolysis and hydrodeoxygenation for upcycling plastic wastes into fuels valuable chemicals.

Language: Английский

Citations

52
Chemical recycling of plastic wastes via homogeneous catalysis: A review DOI

Xueru Chen,

Leilei Cheng,

Jing Gu

et al.

Chemical Engineering Journal, Journal Year: 2023, Volume and Issue: 479, P. 147853 - 147853

Published: Dec. 2, 2023

Language: Английский

Citations

36
Manganese‐Catalyzed Hydroborations with Broad Scope DOI Creative Commons
Pradip Ghosh, Axel Jacobi von Wangelin

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(29), P. 16035 - 16043

Published: April 24, 2021

Reductive transformations of easily available oxidized matter are at the heart synthetic manipulation and chemical valorization. The applications catalytic hydrofunctionalization benefit from use liquid reducing agents operationally facile setups. Metal-catalyzed hydroborations provide a highly prolific platform for reductive valorizations stable C=X electrophiles. Here, we report an especially facile, broad-scope reduction various functions including carbonyls, carboxylates, pyridines, carbodiimides, carbonates under very mild conditions with inexpensive pre-catalyst Mn(hmds)2 . reaction could be successfully applied to depolymerizations.

Language: Английский

Citations

55
Reductive depolymerization of plastics catalyzed with transition metal complexes DOI
Chenyang Wang, O. El-Sepelgy

Current Opinion in Green and Sustainable Chemistry, Journal Year: 2021, Volume and Issue: 32, P. 100547 - 100547

Published: Aug. 18, 2021

Language: Английский

Citations

45
Recent progress in applications of cobalt catalysts in organic reactions DOI
Mohammad Mostafa Tohidi,

Behnaz Paymard,

Salomon Ramiro Vasquez-García

et al.

Tetrahedron, Journal Year: 2023, Volume and Issue: 136, P. 133352 - 133352

Published: March 5, 2023

Language: Английский

Citations

18
Homogeneous First‐row Transition‐metal‐catalyzed Carbon Dioxide Hydrogenation to Formic Acid/Formate, and Methanol DOI

Tushar Singh,

Sachin Jalwal, Subrata Chakraborty

et al.

Asian Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 11(9)

Published: July 9, 2022

Abstract Depletion of fossil fuel for global energy need emits large amount greenhouse gas carbon dioxide into the biosphere. Carbon constitutes a sustainable C1 feedstock and cost‐effective raw material synthesis bulk fine chemicals. The catalytic hydrogenation CO 2 to formic acid, methanol is an attractive protocol owing their application in chemical industry as potential renewable hydrogen storage materials. Catalytic reactions are atom‐economical, green synthetic routes towards various new environmentally benign transformations. Homogeneous based on earth‐abundant, eco‐friendly, first‐row base metals preparation assortment organic scaffolds currently paramount importance academia industry. surge metal catalysis evident from increase reports available literature recent years. In this review, we summarize advances homogeneous transition catalysed direct indirect reduction acid/formate strategy.

Language: Английский

Citations

25
Evaluation of Manganese Catalysts for the Hydrogenative Deconstruction of Commercial and End‐of‐Life Polyurethane Samples DOI
Laurynas Gausas, Bjarke S. Donslund, Steffan K. Kristensen

et al.

ChemSusChem, Journal Year: 2021, Volume and Issue: 15(1)

Published: Sept. 12, 2021

Polyurethane (PU) is a thermoset plastic that found in everyday objects, such as mattresses and shoes, but also more sophisticated materials, including windmills airplanes, insulation materials refrigerators buildings. Because of extensive inter-cross linkages PU, current recycling methods are somewhat lacking. In this work, the effective catalytic hydrogenation PU carried out by applying catalyst based on earth-abundant metal manganese, to give amine polyol fractions, which represent original monomeric composition. particular, Mn-Ph MACHO catalytically deconstruct flexible foam, molded foams, insulation, end-of-life at 1 wt.% loading reaction temperature 180 °C, 50 bar H2 , 0.9 KOH isopropyl alcohol. The protocol showcased deconstruction 2 g mattress foam using only 0.13 catalyst, resulting 90 % weight recovery turnover number 905.

Language: Английский

Citations

30