86657-10-5Relevant academic research and scientific papers
Fluorinated heterocyclic compounds - The first example of an irreversible ring-degenerate rearrangement on five-membered heterocycles by attack of an external bidentate nucleophile
Buscemi, Silvestre,Pace, Andrea,Pibiri, Ivana,Vivona, Nicolo,Lanza, Camilla Zaira,Spinelli, Domenico
, p. 974 - 980 (2004)
The reactions of 5-perfluoroalkyl-1,2,4-oxadiazoles 3 with hydroxylamine in DMF give the regioisomeric 3-perfluoroalkyl-1,2,4-oxadiazoles 4 in excellent yields. This process is the first example of ring-degenerate rearrangement (RDR) occurring on five-membered heterocycles by attack of an external bidentate nucleophile, which replaces two heteroatoms of the ring. We suggest that an ANRORC-like mechanism occurs in which the addition of the nucleophilic nitrogen atom (NH2OH) on the C(5) atom of 3 is followed by ring opening and irreversible ring-degenerate closure by attack of the nucleophilic oxygen atom (=NOH) on the C(3) atom of the original ring, realizing an elegant and efficient synthesis of 4 by a C(3)-C(5) annular switch. Ab initio computations on the starting materials and final products, as well as on the proposed intermediates, support the mechanism and shed light on the features of the reaction. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004.
Trifluoroacetonitrile Oxide
Middleton, William J.
, p. 919 - 922 (2007/10/02)
Trifluoroacetonitrile oxide (1) is a reactive intermediate that can be generated by the dehydrochlorination of trifluoroacetohydroximoyl chloride (2) with base.It reacts with mercaptans and amines in a stereospecific manner to give Z oximes 3 and 15 and forms a cycloadduct (10) with benzonitrile.In the absence of trapping agents, it dimerizes to give either the expected furoxan dimer 7 or the unusual dioxadiazine dimer 8, depending upon conditions.A convenient synthesis for 2 based on hydroxylamine hydrochloride, trifluoroacetic anhydride, and PCl3 was developedto make 1 easily accessible.
