Jingwei Zhao

Iodine-promoted imino-Diels-Alder reaction of fluorinated imine with enol ether: synthesis of 2-perfluorophenyl tetrahydroquinoline derivatives

Iodine was used to catalyze the hetero-Diels-Aider reaction of pentafluorobenzylidineaniline (C6F5CH=NAr 1) with enol ethers to afford the corresponding tetrahydroquinolines derivatives as a mixture of cis/trans stereoisomers in moderate yields. These products could also be prepared by onepot, three-component reaction of pentafluorophenylaldehyde, anilines, and enol ethers under the same reaction condition. Mild and neutral reaction conditions, facile experimental procedure, and low price of iodine should make this method attractive for practical synthesis of many fluorinated tetrahydroquinoline derivatives

Reactions of fluoroalkanesulfonyl azides with cyclic vinyl ethers

The addition reactions of fluoroalkanesulfonyl azides to dihydropyran or dihydrofuran were studied. These reactions do not give the corresponding N-fluoroalkanesulfonyl azilidines but N_fluoroalkanesulfonyl-tetrahydropyranon-2-imines or N-fluoroalkanesulfonyl-tetrahydro-furano-2-imines. The reaction mechanism is discussed.

A new synthetic route of 4,4′-hexafluoroisopropylidene-2,2-bis-(phthalic acid anhydride) and characterization of 4,4′-hexafluoroisopropylidene-2,2-bis-(phthalic acid anhydride)-containing polyimides

Abstract The title product 4,4′-hexafluoroisopropylidene-2,2-bis-(phthalic acid anhydride) was prepared from hexafluoroacetone and o-xylene as the starting materials by condensation, oxidation and dehydration three-step reaction sequence. It reacted with diamines in DMF or xylene to give polyimides by condensation polymerization. Thermal and viscosity analyses show that these polyimides have lower molecular weight but excellent thermal stability.

Three-component reactions involving quinoline or isoquinoline, dialkyl acetylenedicarboxylate and β-trifluoroacetyl vinyl ethyl ether

The three-component reactions (TCRs) involving quinoline or isoquinoline, dialkyl acetylenedicarboxylate and beta-trifluoroacetyl vinyl ethyl ether were investigated. The reaction proceeded smoothly under ambient temperature in DMSO to give the 4-trifluoroacetyl substituted benzo[c]quinolizine derivatives in moderate yields. However, under the same reaction condition, isoquinoline afforded the 2-trifluoromethyl substituted 1-oxa-(11H)-benzo[a]dihydroquinolizine or 4-trifluoroacetyl substituted benzo[a]clihydroquinolizine products. The possible reaction pathways were proposed

Synthetic applications of ethyl 3-bromodifluoromethyl-3-benzyloxy-acrylate as a gem-difluorination building-block: Its reactions with aldehyde and epoxide

Synthetic applications of ethyl 3-bromodifluoromethyl-3-benzyloxy-acrylate as a versatile and multifunctionalized gem-difluorination building block to introduce difluoromethene subunit into some new hydroxy esters have been investigated. It was found that its zinc mediated reaction with a variety of aldehyde in DMF gave the Reformatsky reaction mode product, P-hydroxy ester, in good yield, while its tetrakis(dimethylamino)ethylene (TDAE) promoted reaction with a limited scope of aldehyde produced Barbier reaction mode product, beta-hydroxy ester, in moderate yield. The reaction of its zinc reagent with styrene oxide resulted in rearrangement of the epoxide to 2-phenyl-acetaldehyde, and then the zinc reagent condensed with this aldehyde to provide the Reformastsy reaction type product, beta-hydroxy ester, in low yield. (c) 2006 Elsevier B.V. All rights reserved.

Synthesis of Fullerene-Fused Fluorine-Containing Lactones from the Radical Reaction of [60]Fullerene with Fluorinated Phenylacetic Acids

A series of fullerene-fused fluorinated lactones were prepared by the manganese(III) acetate mediated radical reaction of [60]fullerene (C-60) with fluorinated phenylacetic acids (ArFCH2COOH). Interestingly, the products which contain a 2-fluoro substituent on the benzene ring are mixtures of two stereoisomers due to the stereo and electronic effects of the ortho-fluorine atom.