Chaoyue Qin

A convenient preparation of octafluoro[2,2]paracyclophane and dodecafluoro[2,2]paracyclophane

Abstract A new and convenient synthesis of octafluoro[2,2]paracyclophane and dodeca-fluoro[2,2]paracyclophane is reported. It is accomplished by treatment of 1,4-bis(halodifluoromethyl)benzene with PbBr2/Al in DMF at room temperature via the cyclocoupling of the reactive intermediate α,α,α′α′-tetrafluoro-p-xylylene.

On the Nucleophilic Reactions of 5-Trifluoroacetyl-3,4-dihydro-2H-pyran

Summary. 5-Trifluoroacetyl-3,4-dihydro-2H-pyran react readily with many nucleophiles such as amines and Grignard reagents to give the rign opened products NuCH*CR1R2 (R1: (CH2)3OH, R2:CF3CO). The compound with Nu=Et2N is unstable; it rearranges to 1-hydroxyl-1-trifluoromethyl-2-diethylaminomethylene-tetrahydropyran and 2-diethylamino-3-trifluoroacetyl-tetrahydropyran via an intramolecular nucleophilic addition reaction. Hydrazine and hydroxylamine attack the carbonyl carbon of the title compound to form (CH2)3OCH*CC(CF3)*NZ(Z=NH2, OH). In the presence of KOH, however, hydroxylamine hydrochloride reacts additionally to 2-hydroxyl-2-trifluoromethyl-3-cyano-tetrahydropyran. Upon heating with triethylphosphite, the title compound reacts as a heterodiene and gives the corresponding cyclophosphorane. X-Ray diffraction analyses of two compound are presented.Zusammenfassung. 5-Trifluoracetyl-3,4-dihydro-2H-pyran reagiert bereitwillig mit vielen Nucleophilen wie Aminen oder Grignard-Verbindungen zu ringgeöffneten Produkten des Typs NuCH*CR1R2 (R1: (CH2)3OH, R2: CF3CO). Die Verbindung mit R=Et2N ist instabil und lagert über eine intramolekuare nukleophile Additionsreaktion zum 1-Hydroxy-1-trifluormethyl-2-tetrahydropyran um. Hydrazin und Hydroxylamin greifen das Carbonylkohlenstoffatom der Titelverbindung an und geben dabei Verbindungen des Typs (CH2)3OCH*CC(CF3)*NZ (Z=NH2, OH). In Gegenwart von KOH reagiert Hydroxylamin jedoch zusätzlich zu 2-Hydroxy-2-trifluormethyl-3-cyano-tetrahydropyran. Bei Erhitzen mit Triethylphosphit reagiert die Titelverbindung als Heterodien zum entsprechenden Cyclophosphoran. Die beiden Verbindungen wurden mittels Röntgenstrukturanalyse charakterisiert.

Reactions of 5-trifluoroacetyl-3,4dihydro-2H-pyran with zinc reagents

Abstract One pot reaction of 5-trifluoroacetyl-3,4-dihydro-2H-pyran with alkyl bromides Rbr in the presence of zinc powder gave the corresponding alcohol ( CH 2 ) 3 OCH=C C(R)(CF 3 )OH (R: CH 2 CO 2 Me, 3a ; CH 2 CHCH 2 - 3b ); 3a readily hydrolysed to the corresponding carboxylic acid under dilute acidic conditions, intramolecular cyclo addition of this acid afforded a bicyclo lactone.

Preparation of N,N-dialkyl-N′-perfluoroalkanesulfonylformamidines RfSO2NCHNR2 via Vilsmeier reagents

Abstract Treatment of sodium perfluoroalkanesulfonylamides R f SO 2 NHNa with Vilsmeier reagents [YCH + NR 2 ]Cl − (Y≡OP(O)Cl 2 , OS(O)Cl) give the title compounds R f SO 2 NCHNR 2 in good yields. The molecular structure of I(CF 2 ) 2 O(CF 2 ) 2 SO 2 NCHNMe 2 is presented.

SYNTHESIS OF NOVEL α-(N-PENTAFLUORO-PHENYLAMINO)BENZYLPHOSPHONATES AND PHOSPHONIC ACIDS

Abstract A series of novel α-(N-pentafluorophenylamino)benzyl phosphonic acids are prepared by hydrolysis of corresponding phosphonates, C6F5NHCH(Ar)P(O)(OR)2 which are synthesized from the addition of N-pentafluorophenyl aromatic aldimines with dialkyl phosphite. The X-ray diffraction of C6F5NHCH(4-CH3C6H4)P(O)(OCH3), is presented.

A Novel Synthesis of 2-Fluoroalkyl Quinolines

Summary. 2-Fluoroalkyl quinolines are prepared by reacting aniline with α-fluoroalkyl aldehydes or α-fluoroalkyl cyclohexanones in the presence of acetic acid. Under the same reaction condition, 2-aminophenol gives the corresponding 2-fluoroalkyl-8-quinolinols; in some cases, 2-fluoroalkyl benzoxazoles are also formed as minor products.Zusammenfassung. 2-Fluoralkylchinoline werden durch Reaktion von Anilin mit α-Fluoraldehyden oder α-Fluorcyclohexanonen in Gegenwart von Essigsäure dargestellt. Unter denselben Reaktionsbedingungen gibt 2-Aminophenol die entsprechenden 2-Fluoralkyl-8-chinolinole; in manchen Fällen werden 2-Fluoralkylbenzoxazole als Nebenprodukte gebildet.

Chemical transformation of Bis(perfluoroalkyl)sulfonyl)methanes and 1,1,3,3-Tetraoxopolyfluoro-1,3-dithiaycloalkanes

Halogenation of the potassium or silver salts of bis((trifluoromethyl)sulfonyl)methane(CF3SO2)2CH2 and its cyclo analogues (CF2)nSO2-CH2SO2CF2 with N-fluoro-bis((trifluoromethyl)sul-fonyl)imine (CF3SO2)2NF, chlorine or bromine gave good yields of the corresponding α-halo disulfones (CF3SO2)2CHX and (CF2)nSO2CHXSO2CF2 (X: F, Cl, Br; n = 1,2). Some chemical transformations of these fluorinated α-halo-disulfones are described.

SYNTHESIS OF DIETHYL N-(PERFLUOROALKANESULFONYL) PHOSPHORAMIDATES AND N-(PERF'LUOROALKANESULFONYL) PHOSPHORAMIDIC ACIDS

Abstract N-(perfluoroalkylsulfonyl)phosphoramidates are prepared by the reaction of diethylchloro phosphate CIP(O)(OEt)2 with sodium perfluoroalkylsulfonylamides RfSO2NHNa or sodium N-trimethylsilylperfluoroalkylsulfonylamides RfSO2N(Na)SiMe3 respectively. Hydrolysis of diethyl N-(perfluoroalkylsulfonyl) phosphoramidates under acidic condition did not give the expected RfSO2NHP(O)(OH)2 but led to a brake of the N-P bond forming the corresponding perfluoroalkylsulfonylamides. Silylation of RfSO2NEP(O)(OR)2 with Me3SiBr give high yields of RfSO2NHP(O)(OSiMe3)2 which were then treated with water at room temperature to afford the title phosphoramidic acids.

A convenient one-pot synthesis of per-(or poly-) fluoroalkanesulfonyl substituted cyclopropanes

Abstract Per-(or poly-) fluoroalkanesulfonyl substituted cyclopropanes are prepared by a facile one-pot reaction of methyl per-(or poly-) fluoroalkanesulfones with 1,2-dibromoethane under basic reaction conditions. Similarly treatment of benzyl per-(or poly-) fluoroalkanesulfones gave 1-phenyl-1-per-(or poly-) fluoroalkanesulfonyl cyclopropanes and trans -1,2-diphenylethene as the by-product which was formed by coupling of phenylcarbene.

Syntheses and reactions of N-perfluoroalkanesulfonylimino sulfurous dichlorides

Treatment of N,N-dichloroperfluoroalkanesulfonylamines with sulfur powder at room temperature gave the title products RfSO2N=SCl2 in good yields. They reacted readily with dimethyl sulfoxide, chloral, DMF, benzophenone, and similar compounds to form to corresponding imines RfSO2N=YR1R2 (Y: S, C). A reaction mechanism, one involving formation of a four-membered intermediate, is proposed.