Perfluoro 1,3,4-oxadiazoles

373

P106 Perfluoro 1,3,4-oxadiazoles N. V. Vasiliev, Yu. E. Lyashenko, A. E. Patalakha and G. A. Sokolski Institute of the Physiological Active Substances Cherrwgolmka, Moscow Region 142432 (Russia)

Polyfluorinated symmetrical two-step method:

H,NNH,*2HCl

of the Russian

1,3,4-oxadiazoles

+ 4[&C(O)],O

--+

Academy

of Sciences,

1 have been obtained by a

+ BR&(O)Cl

+ 4RrC(0)OH

NH, Rf 7

0

R

rHCRf

/O\

SOQ,

Q-C-$

NH, Rf

(i 0

//c-%

Rf : CF3, CHF2, C2F5, C3F7, CHF2CF2

N-N 1

Compounds 1 interacted with aliphatic, cyclic and functional alkenes by a two-step mechanism to form the derivatives of 7-oxabicyclo[2.2.l.]heptanes 2. The quantum-chemical calculations of oxadiazoles 1 conhrmed the conclusion on the LUMO-dependent pathway of cycloaddition: R Rf-C

/O\ \

//C-Rf

CHz=CHR ’

Rf

Rf

N-N 1 2

R: H, OCH2CH3,

fi

COCH$H3

Triazole 3 has a similar topology to oxadiazoles 1,one of frontier orbitals and its unreactivity in cycloaddition can be accounted for by the rearrangement of triazole 3:

F

H3

CF 3-CyNA ti N-N 3

//C-CF,

8,

/N\ CF3-C\

,C-CF,

N-N, ‘CH3