scholarly journals Efficacy of Selenourea Organocatalysts in Asymmetric Michael Reactions under Standard and Solvent-Free Conditions

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7303
Author(s):  
Mariola Zielińska-Błajet ◽  
Żaneta A. Mała ◽  
Rafał Kowalczyk
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Ball Mill ◽  
Solvent Free ◽  
Cinchona Alkaloid ◽  
Bifunctional Catalysts ◽  
The Novel ◽  
Michael Reactions ◽  
Solvent Free Conditions ◽  
Hydrogen Bond Donors

By varying the steric and electronic surroundings of the hydrogen-bonding motif, the novel chiral Cinchona-alkaloid based selenoureas were developed. Acting as bifunctional catalysts, they were applied in the Michael reactions of dithiomalonate and nitrostyrene providing chiral adducts with up to 96% ee. The asymmetric Michael–-hemiacetalization reaction of benzylidene pyruvate and dimedone, performed with the assistance of 5 mol% of selenoureas, furnished the product with up to 93% ee and excellent yields. The effectiveness of the new hydrogen-bond donors was also proved in solvent-free reactions under ball mill conditions, supporting the sustainability of the devised catalytic protocol.

B-Doped and NH2-functionalized SBA-15 with hydrogen bond donor groups for effective catalysis of CO2 cycloaddition to epoxides

2020 ◽  
Vol 7 (19) ◽  
pp. 3636-3645 ◽  
Author(s):  
Yifei Ye ◽  
Dazhi Li ◽  
Ping Xu ◽  
Jianmin Sun
Keyword(s):  
Hydrogen Bond ◽  
Lewis Acid ◽  
Catalytic Performance ◽  
Solvent Free ◽  
The Novel ◽  
Hydrogen Bond Donor ◽  
Acid Base ◽  
Solvent Free Conditions ◽  
Base Properties

The novel B-SBA-15-NH2 catalyst with Lewis acid–base properties and hydrogen bond donor groups exhibited good catalytic performance for CO2 conversion under metal- and solvent-free conditions.

Fast, solvent-free and highly enantioselective fluorination of β-keto esters catalyzed by chiral copper complexes in a ball mill

2017 ◽  
Vol 19 (7) ◽  
pp. 1674-1677 ◽  
Author(s):  
Yifeng Wang ◽  
Haojiang Wang ◽  
Yidong Jiang ◽  
Cheng Zhang ◽  
Juanjuan Shao ◽  
...  
Keyword(s):  
Ball Mill ◽  
Copper Complexes ◽  
Solvent Free ◽  
Planetary Ball Mill ◽  
Keto Esters ◽  
Solvent Free Conditions

A fast and highly enantioselective fluorination of β-keto esters catalyzed by diphenylamine linked bis(oxazoline)-Cu(OTf)2 complexes under solvent-free conditions has been developed using a planetary ball mill.

ChemInform Abstract: Fast, Solvent-Free and Hydrogen-Bonding-Mediated Asymmetric Michael Addition in a Ball Mill.

ChemInform ◽  
2012 ◽  
Vol 43 (34) ◽  
pp. no-no
Author(s):  
Yi-Feng Wang ◽  
Ru-Xiang Chen ◽  
Ke Wang ◽  
Bin-Bin Zhang ◽  
Zhao-Bo Li ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Michael Addition ◽  
Ball Mill ◽  
Solvent Free ◽  
Asymmetric Michael Addition

scholarly journals DBU Catalyzed Phospho-Aldol-Brook Rearrangement for Rapid Preparation of α-Phosphates Amide in Solvent-Free Conditions

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1445
Author(s):  
Shunhong Chen ◽  
Shengxin Guo ◽  
Feng He ◽  
Yingxia Zhang ◽  
Zengxue Wu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Solvent Free ◽  
The Novel ◽  
Rapid Preparation ◽  
Good Tolerance ◽  
Amide Derivatives ◽  
Solvent Free Conditions ◽  
Brook Rearrangement ◽  
Rearrangement Reaction ◽  
Dialkyl Phosphites

The 1,8-diazabicyclo [5.4.0] undec-7-ene DBU-catalyzed Phospho-Aldol-Brook Rearrangement reaction of α-ketoamide and dialkyl phosphites was developed under solvent-free at room temperature. The novel α-Phosphate Amide derivatives could be obtained with good yield (86–96%), which also exhibited good tolerance of various dialkyl phosphites and α-ketoamide, including isatins. In addition, the reaction was conducted in both gram-scale and mol-scale, and the title compounds could also be obtained in excellent yield (more than 91%) within 5 min.

Synthesis of Phosphine Chalcogenides Under Solvent-Free Conditions Using a Rotary Ball Mill

2018 ◽  
Vol 2018 (8) ◽  
pp. 1028-1037 ◽  
Author(s):  
Rajnish Kumar ◽  
Saurabh Kumar ◽  
Madhusudan K. Pandey ◽  
Vitthalrao S. Kashid ◽  
Latchupatula Radhakrishna ◽  
...  
Keyword(s):  
Ball Mill ◽  
Solvent Free ◽  
Solvent Free Conditions ◽  
Phosphine Chalcogenides

scholarly journals Efficient mechanochemical synthesis of regioselective persubstituted cyclodextrins

2016 ◽  
Vol 12 ◽  
pp. 2364-2371 ◽  
Author(s):  
Laszlo Jicsinszky ◽  
Marina Caporaso ◽  
Katia Martina ◽  
Emanuela Calcio Gaudino ◽  
Giancarlo Cravotto
Keyword(s):  
Mechanochemical Synthesis ◽  
Ball Mill ◽  
Solvent Free ◽  
Planetary Ball Mill ◽  
Aprotic Solvents ◽  
Isolation And Purification ◽  
Cyclodextrin Derivative ◽  
Complete Reaction ◽  
Solvent Free Conditions

A number of per-6-substituted cyclodextrin derivative syntheses have been effectively carried out in a planetary ball mill under solvent-free conditions. The preparation of Bridion® and important per-6-amino/thiocyclodextrin intermediates without polar aprotic solvents, a source of byproducts and persistent impurities, could be performed. Isolation and purification processes could also be simplified. Considerably lower alkylthiol/halide ratio were necessary to reach the complete reaction in comparison with thiourea or azide reactions. While the presented mechanochemical syntheses were carried out on the millimolar scale, they are easily scalable.

2-Ethyl-1-[5-(4-methylphenyl)pyrazol-3-yl]-3-(thiophene-2-carbonyl)isothiourea: molecular ribbons containing three types of hydrogen-bonded ring

2014 ◽  
Vol 70 (11) ◽  
pp. 1064-1068
Author(s):  
Edison Castro ◽  
Henry Insuasty ◽  
Braulio Insuasty ◽  
Justo Cobo ◽  
Christopher Glidewell
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonds ◽  
Microwave Irradiation ◽  
Title Compound ◽  
Pyrazole Ring ◽  
Solvent Free ◽  
Compound C ◽  
Solvent Free Conditions ◽  
Hydrogen Bonded

The title compound, C18H18N4OS2, was prepared by reaction ofS,S-diethyl 2-thenoylimidodithiocarbonate with 5-amino-3-(4-methylphenyl)-1H-pyrazole using microwave irradiation under solvent-free conditions. In the molecule, the thiophene unit is disordered over two sets of atomic sites, with occupancies of 0.814 (4) and 0.186 (4), and the bonded distances provide evidence for polarization in the acylthiourea fragment and for aromatic type delocalization in the pyrazole ring. An intramolecular N—H...O hydrogen bond is present, forming anS(6) motif, and molecules are linked by N—H...O and N—H...N hydrogen bonds to form a ribbon in which centrosymmetricR22(4) rings, built from N—H...O hydrogen bonds and flanked by inversion-related pairs ofS(6) rings, alternate with centrosymmetricR22(6) rings built from N—H...N hydrogen bonds.

Stabilization of synthetic heme-superoxo complexes by hydrogen bonding: a still on-going quest

2018 ◽  
Vol 42 (10) ◽  
pp. 7516-7521 ◽  
Author(s):  
Bernard Boitrel ◽  
Stéphane Le Gac
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Fine Tuning ◽  
Apical Position ◽  
Coordination Site ◽  
Hydrogen Bond Donors

The design of various types of synthetic heme models has allowed the fine tuning of the location of hydrogen bond donors around the ferrous coordination site. Through the years, it has migrated from a lateral to a quasi-apical position. Still, the unambiguous existence of an actual H-bond with the dioxygen adduct remains to be established.

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