ChemInform Abstract: Asymmetric Friedel-Crafts Alkylation Reaction in the Construction of Trifluoromethylated All-Carbon Quaternary Stereocenters.

ChemInform ◽  
2014 ◽  
Vol 45 (33) ◽  
pp. no-no ◽  
Author(s):  
Hao Wu ◽  
Ren-Rong Liu ◽  
Yi-Xia Jia
Keyword(s):  
Alkylation Reaction ◽  
Quaternary Stereocenters

scholarly journals Highly Enantioselective Iridium(I)‐Catalyzed Hydrocarbonation of Alkenes: A Versatile Approach to Heterocyclic Systems Bearing Quaternary Stereocenters

2021 ◽  
Author(s):  
Andrés Arribas ◽  
Martín Calvelo ◽  
David F. Fernández ◽  
Catarina A. B. Rodrigues ◽  
José L. Mascareñas ◽  
...  
Keyword(s):  
Quaternary Stereocenters

scholarly journals A cross-dehydrogenative C(sp3)−H heteroarylation via photo-induced catalytic chlorine radical generation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chia-Yu Huang ◽  
Jianbin Li ◽  
Chao-Jun Li
Keyword(s):  
Hydrogen Atom ◽  
Hydrogen Evolution ◽  
Alkyl Radical ◽  
Cobalt Catalyst ◽  
Alkylation Reaction ◽  
Hydrogen Atom Abstraction ◽  
Dehydrogenative Coupling ◽  
Radical Generation ◽  
Limited Scope

AbstractHydrogen atom abstraction (HAT) from C(sp3)–H bonds of naturally abundant alkanes for alkyl radical generation represents a promising yet underexplored strategy in the alkylation reaction designs since involving stoichiometric oxidants, excessive alkane loading, and limited scope are common drawbacks. Here we report a photo-induced and chemical oxidant-free cross-dehydrogenative coupling (CDC) between alkanes and heteroarenes using catalytic chloride and cobalt catalyst. Couplings of strong C(sp3)–H bond-containing substrates and complex heteroarenes, have been achieved with satisfactory yields. This dual catalytic platform features the in situ engendered chlorine radical for alkyl radical generation and exploits the cobaloxime catalyst to enable the hydrogen evolution for catalytic turnover. The practical value of this protocol was demonstrated by the gram-scale synthesis of alkylated heteroarene with merely 3 equiv. alkane loading.

scholarly journals Incorporation of Poly(Itaconic Acid) with Quaternized Thiazole Groups on Gelatin-Based Films for Antimicrobial-Active Food Packaging

Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 200
Author(s):  
Celeste Cottet ◽  
Andrés G. Salvay ◽  
Mercedes A. Peltzer ◽  
Marta Fernández-García
Keyword(s):  
Antimicrobial Activity ◽  
Itaconic Acid ◽  
Food Packaging ◽  
Crosslinking Agent ◽  
Radical Scavenging ◽  
Proton Nuclear Magnetic Resonance ◽  
Esterification Reaction ◽  
Alkylation Reaction ◽  
Vapor Permeability ◽  
Active Food Packaging

Poly(itaconic acid) (PIA) was synthesized via conventional radical polymerization. Then, functionalization of PIA was carried out by an esterification reaction with the heterocyclic groups of 1,3-thiazole and posterior quaternization by N-alkylation reaction with iodomethane. The modifications were confirmed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H-NMR), as well as ζ-potential measurements. Their antimicrobial activity was tested against different Gram-negative and Gram-positive bacteria. After characterization, the resulting polymers were incorporated into gelatin with oxidized starch and glycerol as film adjuvants, and dopamine as crosslinking agent, to develop antimicrobial-active films. The addition of quaternized polymers not only improved the mechanical properties of gelatin formulations, but also decreased the solution absorption capacity during the swelling process. However, the incorporation of synthesized polymers increased the deformation at break values and the water vapor permeability of films. The antioxidant capacity of films was confirmed by radical scavenging ability and, additionally, those films exhibited antimicrobial activity. Therefore, these films can be considered as good candidates for active packaging, ensuring a constant concentration of the active compound on the surface of the food, increasing products’ shelf-life and reducing the environmental impact generated by plastics of petrochemical origin.

Iminophosphorane-mediated regioselective umpolung alkylation reaction of α-iminoesters

2021 ◽  
Author(s):  
Yasushi Yoshida ◽  
Mayu Kukita ◽  
Kazuki Omori ◽  
Takashi Mino ◽  
Masami Sakamoto
Keyword(s):  
Asymmetric Reactions ◽  
Alkylation Reaction ◽  
Chiral Amines ◽  
Efficient Manner

Umpolung reactions of imines, especially the asymmetric reactions, have been extensively studied as they provide access to important chiral amines in an efficient manner. The reactions studied range from simple...

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