THE RADICAL NUCLEOPHILIC SUBSTITUTION REACTION OF HETEROCYCLIC KETENE AMINALS WITH 2,4-DINITROHALOBENZENES

The anion of heterocyclic ketene aminals reacted with 2,4-dini- tro-halobenzenes to give an arylated product through the radical nucleo- philic substitution confirmed by ESR spectroscopy,ESR-spin trapping techni- que,and depression of the reaction rate by the addition of inhibitor.

SYNTHESIS AND APPLICATIONS OF CROSS-LINKED POLY(DIALLYLDIMETHYL AMMONIUM CHLORIDE) AND ITS DERIVATIVE COPOLYMERS AS EFFICIENT PHASE TRANSFER CATALYST FOR NUCLEOPHILIC SUBSTITUTION REACTIONS

Cross-linked poly（diallyldimethylammonium chloride） and its derivative copolymers were synthesized and used as phase transfer catalyst in the nucleophilic substitution reaction especially halogen exchange reactions.In addition,the effect of hydrophilic-hydrophobic character of the polymers in the nucleophilic reactions was investigated.

Towards the gemini cation anion exchange membranes by nucleophilic substitution reaction

As a critical component of alkaline fuel cells, anion exchange membranes determine the energy efficiency, output power density and the long term stability. Recently, the anion exchange membranes with gemini-cation side chains exhibit superior ion conductivity due to their good nanophase separation. However, the costly and complicated synthesis limits their scaling up and commercialization. To address this problem, a convenient synthetic procedure under mild conditions is well developed. A tertiary amine precursor is introduced onto the polymer by the nucleophilic substitution reaction to avoid the conventional chloro/bromo-methylation. Followed by a simple Menshutkin reaction with 6- bromo-N,N,N-trimethylhexan-1-am inium bromide, the polym er electrolytes are obtained in a high yield. The resulting anion exchange membranes with high conductivity, good fuel cell performance and restricted swelling suggest the potential for the application in fuel cell devices.

Facile microwave-assisted synthesis of 1H-pyrazino[1,2-a]quinoxaline-1,5(6H)-dione derivatives via a nucleophilic substitution reaction

A series of compounds containing the 1H-pyrazino[1,2-a]quinoxaline-1,5(6H)-dione scaffold have been synthesized using a one-pot procedure under microwave irradiation. This new strategy allowed for the facile synthesis of target compounds in good yields and could be readily applied to the construction of diverse libraries of compounds for high throughput screening in medicinal chemistry.

STRUCTURE AND PROPERTIES OF PHOSPHROUS-CONTAINING POLY(ARYLETHER KETONE)WITH BISPHENOL-A MOIETY

A phosphrous-containing poly（aryl ether ketone） was synthesized derived from bisphenol-A and bis[4-（4- fluorobenzoyl）phenyl] phenyl phosphine oxide （FPPPO） by nucleophilic substitution reaction. The structure of the polymer was characterized by FT-IR, ^1H-NMR and ^31p-NMR. The thermal property of the PAEK was measured by DSC and TGA. The glass transition temperature （Tg） of the polymer was 205℃, and the 5% weight loss temperature under nitrogen was 475℃. Good solubility of the polymer in organic solvents, such as N-methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethylsulfoxide and chloroalkanes was observed, flexible film was obtained from the polymer＇s CH2Cl2 solution. The limiting oxygen index （LOI） of the PAEK was 40, which indicated that organic phosphorus moiety can offer good flame retardant property to the polymer.

A facile method for building fused quinoxaline-quinolinones via an acidless post-Ugi cascade reaction

A series of quinolino[3,4-b]quinoxalin-6（5H）-ones have been synthesized using an Ugi/deprotection/cyclization（UDC） strategy, followed by a nucleophilic aromatic substitution reaction. This facile microwave-assisted method provided good yields and could potentially be used for the construction of a diverse library of quinolino[3,4-b]quinoxalin-6（5H）-ones for high-throughput screening in medicinal chemistry.

Facile Synthesis of Novel Perfluorocarbon-Modulated 4-Anilinoquinazoline Analogues

4-Anilinoquinazoline analogues stand out among many kinds of small molecules that inhibit the tyrosine kinase activities of epidermal growth factor receptor （EGFR）, thus serving as significant molecular targets for anticancer drug design. Herein, a series of novel perfluorocarbon （PFC） modulated 4-anilinoquinazolines were designed and prepared straightforwardly by nucleophilic substitution reaction of various anilinoquinazolines and PFC-derived methanesulfonate. In the presence of base, the reaction proceeded smoothly to afford a wide range of 4-anilino- quinazolines with different substituents on aniline moiety in good to high yields. Furthermore, the PFC-modified analogues of gefitinib and erlotinib were also obtained in 93% and 90% respectively, which may have potential for developing new inhibitors of the epidermal growth factor receptor （EGFR） tyrosine kinase and fluorinated contrast agents （CA） for 19F MRI.

Benzylic aroylation of toluenes with unactivated tertiary benzamides promoted by directed ortho-lithiation

The deprotonative functionalization of toluenes,for their weak acidity,generally needs strong bases,thus leading to the requirement of harsh conditions and the generation of by-products.Direct nucleophilic acyl substitution reaction of amides with organometallic reagents could provide an ideal solution for ketone synthesis.However,the inert amides and highly reactive organometallic reagents bring great challenges for an efficient and selective synthetic approach.Herein,we reported an lithium diisopropylamide(LDA)-promoted benzylic aroylation of toluenes with unactivated tertiary benzamides,providing a direct and efficient synthesis of various aryl benzyl ketones.This process features a kinetic deprotonative functionalization of toluenes with a readily available base LDA.Mechanism studies revealed that the directed ortho-lithiation of the tertiary benzamide with LDA promoted the benzylic kinetic deprotonation of toluene and triggered the nucleophilic acyl substitution reaction with the amide.