Oxokohlenstoffe und verwandte Verbindungen. 32 [1]. Über die Umsetzung von Quadratsäuredichlorid und Perchlorcyclobutenon mit SchiffBasen

2008 ◽  
Vol 63 (7) ◽  
pp. 1-7
Author(s):  
Arthur H. Schmidt ◽  
Peter Müllen ◽  
Gabriele Wallmeyer ◽  
Claudia Plutniok ◽  
Peter R. Wiesert
Keyword(s):  
Schiff Bases ◽  
Good Yield ◽  
Mild Conditions ◽  
Hydrolysis Of

Squaric dichloride (3) reacts with Schiff bases 5 under mild conditions to give 1 : 1 adducts 7. On recrystallisation from alcohols, these adducts are converted to the respective N-(α-alkoxybenzyl)- squaric amide chlorides 8. The reaction has been extended to perchlorocyclobutenone 4. Thus, addition products 14 have been obtained from the reaction of 4 with Schiff bases 5, which, on recrystallisation from alcohols, afforded N-(α-alkoxybenzyl)-substituted 3-amino-2,4,4-trichloro-cyclobuten- 1-ones 15. Hydrolysis of the adducts 14 gave the aminotrichlorocyclobutenones 17 in good yield.

scholarly journals Cleaner and Efficient Green Chemistry Synthesis of N,N´-Dibenzyl or N,N´-(2-Hydroxybenzyl)-Ethane-1,2-Diamine,-Propane-1,3-Diamine and -1,3-Diamino-2-Propanol

2016 ◽  
Vol 8 (4) ◽  
pp. 62 ◽  
Author(s):  
Augusto Rivera ◽  
Ingrid Miranda-Carvajal ◽  
Jaime Ríos-Motta
Keyword(s):  
Green Chemistry ◽  
Schiff Bases ◽  
Sodium Borohydride ◽  
Good Yield ◽  
Solvent Free ◽  
Mild Conditions ◽  
Excellent Yield ◽  
High Yields ◽  
Work Up

<p>An efficient and highly eco-friendly protocol for the preparation of <em>N,N´</em>-dibenzyl or <em>N,N´</em>-(2-hydroxybenzyl)diamines via the reduction of the corresponding di-Schiff bases that produces a good yield using water as a solvent without the need for catalysis or the azeotropic removal of water has been developed. These symmetric diimines have been reduced to their corresponding diamines with sodium borohydride using a catalyst- and solvent-free protocol with excellent yield. Mild conditions, high yields, and a simple work-up procedure are the primary benefits of this protocol.</p>

Effect of removing hemicellulose and lignin synchronously under mild conditions on enzymatic hydrolysis of corn stover

2020 ◽  
Vol 204 ◽  
pp. 106407 ◽  
Author(s):  
Shengxin An ◽  
Wenzhi Li ◽  
Fengyang Xue ◽  
Xu Li ◽  
Ying Xia ◽  
...  
Keyword(s):  
Enzymatic Hydrolysis ◽  
Corn Stover ◽  
Mild Conditions ◽  
Hydrolysis Of

Kinetics of Hydrolysis of Some Bifunctional Schiff Bases

1990 ◽  
Vol 37 (5) ◽  
pp. 479-487 ◽  
Author(s):  
M.R. Mahmoud ◽  
A.M. El-Nady ◽  
F.A. Adam ◽  
M.A. El-Taher
Keyword(s):  
Schiff Bases ◽  
Kinetics Of Hydrolysis ◽  
Kinetics Of ◽  
Hydrolysis Of

scholarly journals Optimized acid hydrolysis of the polysaccharides from the seaweed Solieria filiformis (Kützing) P.W. Gabrielson for bioethanol production

2017 ◽  
Vol 39 (4) ◽  
pp. 423 ◽  
Author(s):  
George Meredite Cunha de Castro ◽  
Norma Maria Barros Benevides ◽  
Maulori Curié Cabral ◽  
Rafael De Souza Miranda ◽  
Enéas Gomes Filho ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Sulfuric Acid ◽  
Acid Hydrolysis ◽  
Kinetic Parameters ◽  
Renewable Resource ◽  
Bioethanol Production ◽  
Seaweed Species ◽  
Mild Conditions ◽  
Hydrolysis Of ◽  
Solieria Filiformis

 The seaweeds are bio-resource rich in sulfated and neutral polysaccharides. The tropical seaweed species used in this study (Solieria filiformis), after dried, shows 65.8% (w/w) carbohydrate, 9.6% (w/w) protein, 1.7% (w/w) lipid, 7.0% (w/w) moisture and 15.9% (w/w) ash. The dried seaweed was easily hydrolyzed under mild conditions (0.5 M sulfuric acid, 20 min.), generating fermentable monosaccharides with a maximum hydrolysis efficiency of 63.21%. Galactose and glucose present in the hydrolyzed were simultaneously fermented by Saccharomyces cerevisiae when the yeast was acclimated to galactose and cultivated in broth containing only galactose. The kinetic parameters of the fermentation of the seaweed hydrolyzed were Y(P⁄S) = 0.48 ± 0.02 g.g−1, PP = 0.27 ± 0.04 g.L−1.h−1, h = 94.1%, representing a 41% increase in bioethanol productivity. Therefore, S. filiformis was a promising renewable resource of polysaccharides easily hydrolyzed, generating a broth rich in fermentable monosaccharides for ethanol production. 

Synthesis of Symmetrical Dipurine-Nucleoside Diphosphates from the Corresponding Nucleoside Phosphoropiperidates

2014 ◽  
Vol 1023 ◽  
pp. 55-58
Author(s):  
Xiao Chuan Li ◽  
Shan Shan Gong ◽  
Qi Sun
Keyword(s):  
Efficient Method ◽  
Good Yield ◽  
Purine Bases ◽  
Hydrolysis Of

A general and efficient method for the preparation of symmetrical dinucleoside diphosphates with purine bases has been developed. Ap2A and Gp2G were synthesized from the in situ hydrolysis of corresponding nucleoside 5′-phosphoropiperidates with 4,5-dicyanoimidazole as the activator. This method features easily accessible starting materials, simple procedures, and good yield.

Palladium-Catalyzed Desulfurative Hiyama Coupling of Thioureas to Achieve Amides via Selective C–N Bond Cleavage

Synthesis ◽  
2021 ◽  
Author(s):  
Zhuo Zeng ◽  
Zhanyu He ◽  
Chu Yan ◽  
Mei Zhang ◽  
Majeed Irfan ◽  
...  
Keyword(s):  
Good Yield ◽  
Bond Cleavage ◽  
New Approach ◽  
Mild Conditions ◽  
Palladium Catalyzed

AbstractPalladium-catalyzed Hiyama coupling of active thioureas via selective C–N bond cleavage is reported. Notably, the new approach employed active thioureas as coupling partners in the presence of arylsilanes to give amides in good yield. Further, this strategy, which utilized CuF2 as a key oxidant and activator, afforded various amide products under mild conditions and an easy to handle procedure without extra base.

Arene chromium complexes with functionalized anellated rings. Selective formation of highly substituted polycycles

2002 ◽  
Vol 74 (1) ◽  
pp. 57-62 ◽  
Author(s):  
Holger Butenschön
Keyword(s):  
Good Yield ◽  
Ring Opening ◽  
Ring Expansion ◽  
Chromium Complexes ◽  
Ketone Group ◽  
Aldol Additions ◽  
Cope Rearrangements ◽  
Hydrolysis Of ◽  
Selective Formation ◽  
Tricarbonylchromium Complexes

Tricarbonylchromium complexes of benzocyclobutenone, benzocyclobutenedione, and 1,3-indandione are readily prepared by hydrolysis of the complexes of the corresponding acetals. Reduction of the benzocyclobutenone complex gives rise to an oxy-anion-driven ring opening to the corresponding ortho-quinodimethane intermediate, which can be trapped with dienophiles. Addition of 1-ethoxy-1-lithioethene allows a stereoselective ring expansion followed by an anionic ketol rearrangement with complete diastereoselectivity. Addition of 1-lithio-1-methoxyallene gives rise to a rare anionic 1-vinylcyclobutenol-cyclohexadienol rearrangement. Diaddition of alkenylmetal reagents at both keto groups in benzoyclobutenedione complexes causes dianionic oxy-Cope rearrangements to occur at ­78 °C, which are followed by diastereoselective intramolecular aldol additions. In some cases, a completely regioselective mono hydrolysis of di(enolates) was observed. Dianionic oxy-Cope rearrangements can also be realized with unstrained benzil derivatives giving 1,6-hexanediones and the corresponding aldol adducts. The 1,2,3-indantrione complex is obtained by oxidation of the 1,3-indandione complex with dimethyldioxirane in good yield and reacts with its central ketone group in hetero Diels­Alder cycloadditions.

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