Catalyst-free nucleophilic addition reactions of silyl glyoxylates in water

2018 ◽  
Vol 20 (6) ◽  
pp. 1228-1232 ◽  
Author(s):  
Man-Yi Han ◽  
Jing Lin ◽  
Wei Li ◽  
Wen-Yu Luan ◽  
Pei-Lin Mai ◽  
...  
Keyword(s):  
Nucleophilic Addition ◽  
Addition Reaction ◽  
Addition Reactions ◽  
Catalyst Free ◽  
Silyl Glyoxylates ◽  
Efficient Route ◽  
Novel Catalyst

A novel catalyst-free addition reaction of thiols to silyl glyoxylates is developed in water, providing an efficient route for the synthesis of α-hydroxysilanes.

Synthesis of functionalized isoxazole–oxindole hybrids via on water, catalyst free vinylogous Henry and 1,6-Michael addition reactions

RSC Advances ◽  
2015 ◽  
Vol 5 (100) ◽  
pp. 81768-81773 ◽  
Author(s):  
Sakkani Nagaraju ◽  
Neeli Satyanarayana ◽  
Banoth Paplal ◽  
Anuji K. Vasu ◽  
Sriram Kanvah ◽  
...  
Keyword(s):  
Michael Addition ◽  
Addition Reaction ◽  
Addition Reactions ◽  
Michael Addition Reaction ◽  
Henry Reaction ◽  
Catalyst Free

Various isoxazole–oxindole hybrids were synthesized via vinylogous Henry reaction of 3,5-dimethyl-4-nitroisoxazole and isatin under catalyst free conditions in water. The products obtained were functionalized using 1,6-Michael addition reaction.

Highly Efficient “On Water” Catalyst-Free Nucleophilic Addition Reactions Using Difluoroenoxysilanes: Dramatic Fluorine Effects

2014 ◽  
Vol 126 (36) ◽  
pp. 9666-9670 ◽  
Author(s):  
Jin-Sheng Yu ◽  
Yun-Lin Liu ◽  
Jing Tang ◽  
Xin Wang ◽  
Jian Zhou
Keyword(s):  
Nucleophilic Addition ◽  
Addition Reactions ◽  
Catalyst Free ◽  
Highly Efficient

scholarly journals Recoverable Phospha-Michael Additions Catalyzed by a 4-N,N-Dimethylaminopyridinium Saccharinate Salt or a Fluorous Long-Chained Pyridine: Two Types of Reusable Base Catalysts

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 1159
Author(s):  
Eskedar Tessema ◽  
Vijayanath Elakkat ◽  
Chiao-Fan Chiu ◽  
Jing-Hung Zheng ◽  
Ka Long Chan ◽  
...  
Keyword(s):  
Michael Addition ◽  
Polar Solvent ◽  
Addition Reaction ◽  
High Yield ◽  
Addition Reactions ◽  
Polar Solvents ◽  
Unsaturated Bond ◽  
Base Catalysts ◽  
Michael Additions

Phospha-Michael addition, which is the addition reaction of a phosphorus-based nucleophile to an acceptor-substituted unsaturated bond, certainly represents one of the most versatile and powerful tools for the formation of P-C bonds, since many different electrophiles and P nucleophiles can be combined with each other. This offers the possibility to access many diversely functionalized products. In this work, two kinds of basic pyridine-based organo-catalysts were used to efficiently catalyze phospha-Michael addition reactions, the 4-N,N-dimethylaminopyridinium saccharinate (DMAP·Hsac) salt and a fluorous long-chained pyridine (4-Rf-CH2OCH2-py, where Rf = C11F23). These catalysts have been synthesized and characterized by Lu’s group. The phospha-Michael addition of diisopropyl, dimethyl or triethyl phosphites to α, β-unsaturated malonates in the presence of those catalysts showed very good reactivity with high yield at 80–100 °C in 1–4.5 h with high catalytic recovery and reusability. With regard to significant catalytic recovery, sometimes more than eight cycles were observed for DMAP·Hsac adduct by using non-polar solvents (e.g., ether) to precipitate out the catalyst. In the case of the fluorous long-chained pyridine, the thermomorphic method was used to efficiently recover the catalyst for eight cycles in all the reactions. Thus, the easy separation of the catalysts from the products revealed the outstanding efficacy of our systems. To our knowledge, these are good examples of the application of recoverable organo-catalysts to the DMAP·Hsac adduct by using non-polar solvent and a fluorous long-chained pyridine under the thermomorphic mode in phospha-Michael addition reactions.

Layer by layer assembled functionalized graphene oxide-based polymer brushes for superlubricity on steel-steel tribocontact

Soft Matter ◽  
2021 ◽  
Author(s):  
Suprakash Samanta ◽  
Rashmi Ranjan Sahoo
Keyword(s):  
Graphene Oxide ◽  
Nucleophilic Addition ◽  
Polymer Brushes ◽  
Addition Reaction ◽  
Layer By Layer ◽  
Functionalized Graphene ◽  
Covalent Functionalization ◽  
Functionalized Graphene Oxide ◽  
Nucleophilic Addition Reaction ◽  
Branched Polyethylenimine

Present study demonstrates a simple and multistep approach for the preparation of covalent functionalization of chemically prepared graphene oxide (GO) by branched polyethylenimine (PEI) through nucleophilic addition reaction to prepare...

scholarly journals Synthesis of Network Polymers by Means of Addition Reactions of Multifunctional-Amine and Poly(ethylene glycol) Diglycidyl Ether or Diacrylate Compounds

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2047
Author(s):  
Naofumi Naga ◽  
Mitsusuke Sato ◽  
Kensuke Mori ◽  
Hassan Nageh ◽  
Tamaki Nakano
Keyword(s):  
Ethylene Glycol ◽  
Room Temperature ◽  
Addition Reaction ◽  
Monomer Concentration ◽  
Diglycidyl Ether ◽  
Porous Polymers ◽  
Addition Reactions ◽  
Poly Ethylene Glycol ◽  
Network Polymers ◽  
Poly Ethylene

Addition reactions of multi-functional amine, polyethylene imine (PEI) or diethylenetriamine (DETA), and poly(ethylene glycol) diglycidyl ether (PEGDE) or poly(ethylene glycol) diacrylate (PEGDA), have been investigated to obtain network polymers in H2O, dimethyl sulfoxide (DMSO), and ethanol (EtOH). Ring opening addition reaction of the multi-functional amine and PEGDE in H2O at room temperature or in DMSO at 90 °C using triphenylphosphine as a catalyst yielded gels. Aza-Michael addition reaction of the multi-functional amine and PEGDA in DMSO or EtOH at room temperature also yielded corresponding gels. Compression test of the gels obtained with PEI showed higher Young’s modulus than those with DETA. The reactions of the multi-functional amine and low molecular weight PEGDA in EtOH under the specific conditions yielded porous polymers induced by phase separation during the network formation. The morphology of the porous polymers could be controlled by the reaction conditions, especially monomer concentration and feed ratio of the multi-functional amine to PEGDA of the reaction system. The porous structure was formed by connected spheres or a co-continuous monolithic structure. The porous polymers were unbreakable by compression, and their Young’s modulus increased with the increase in the monomer concentration of the reaction systems. The porous polymers absorbed various solvents derived from high affinity between the polyethylene glycol units in the network structure and the solvents.

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