Eike Hoppmann

Synthesis of (all-rac)-α-Tocopherol Using Fluorinated NH-Acidic Catalysts

The synthesis of (all-rac)-α-tocopherol starting from trimethylhydroquinone and isophytol using fluorinated NH-acidic catalysts is described. Scope and limitations of this type of catalysts are discussed. Advantages of this new procedure are high yield and selectivity, no waste problem and mild reaction conditions. Best results in the synthesis of (all-rac)-α-tocopherol (94% yield) using NH-acidic compounds are obtained in polar solvents. The used catalyst could be recovered.

The first synthesis of fluorine-containing indeno[2,1c][1,2,6]-selenadiazines

Abstract 4-Trifluoromethyl-4a-chloro-5,6,7,8,9,9-hexafluoro(4aH,9H)indeno[2,1c][1,2,6]-selenadiazine (1) has been synthesised by the interaction of 2-amino-3-(1-imino-2,2,2-trifluoroethyl)hexafluoroindene (2) with SeCl4 in the presence of HCl acceptors. Hydrolysis and reaction with CF3SO3H are also described. Arrangement of atoms for 1 are provided.

Preparation of Tellurium-Nitrogen containing Moieties in Ionic Chainmolecules, Heterocycles, as well as (CF3Se)2Te, (CF3S)2Se, and (CH3)2Te(X)Y (X = Y = NCO, NSO; X = Cl, Y = NSO)

The reaction between Cl2Te(NSO)2, Cl6Te2N2S and Cl2Te(N=S=N)2TeCl2 with MCl3 provided the compounds [(Cl2Te)2N+][MCl4–] (M = Ga, Al, Fe). Treating Cl6Te2N2S with M′Cl3 yielded besides [(Cl2Te)2N+][M′Cl4–] (M′ = Al, Fe) the sulfur containing compound [ClTeNSNS+][M′Cl4–]. The structure for [ClTeNSNS+][FeCl4–] was established by an X-ray structure analysis. With Te(NSO)2 and CF3SCl, via Cl2Te(NSO)2, the known compound Te2NCl5 was formed. Tetrafluoroditelluradiazetidine was obtained from TeF4 and [(CH3)3Si]2NH which on treating with (CH3)3SiCl provided the corresponding chloroderivative. In addition metathetical reaction between Cl2TeNSNS and CF3C(O)OAg yielded [CF3C(O)O]2TeSNSN. Similarly (CH3)2Te(NSO)2–xClx (x = 0,1) and (CH3)2Te(NCO)2 were made from (CH3)2TeCl2 and AgNSO or AgNCO, respectively. Halogination of Cl2Te(N=S=N)2TeCl2 with Cl2 or Br2 yielded Cl6Te2N2S and Cl4Br2Te2N2S. The bromoderivate was also prepared from Cl2Te(NSO)2 and Br2. AgNSO was synthesized by treating CF3C(O)OAg with (CH3)3SiNSO. Two other synthons (CF3Se)2Te and (CF3S)2Se were obtained from CF3SeCl and Na2Te and from Hg(SCF3)2 plus SeCl4, respectively. Darstellung von Tellur-Stickstoff-Einheiten in ionischen Kettenmolekulen, Heterozyklen sowie (CF3Se)2Te, (CF3S)2Se und (CH3)2Te(X)Y (X = Y = NCO, NSO; X = Cl, Y = NSO) Umsetzungen von Cl2Te(NSO)2; Cl6Te2N2S und Cl2Te(NSN)2TeCl2 mit MCl3 fuhrten zu [(Cl2Te)2N+][MCl4–] (M = Ga, Al, Fe). Mit M′Cl3 entstanden neben [(Cl2Te)2N+][M′Cl4–] die schwefelhaltigen Substanzen [ClTeNSNS+][M′Cl4–] (M = Al, Fe). Die Rontgenstrukturanalyse bestatigte die Struktur von [ClTeNSNS+][FeCl4–]. Mit Te(NSO)2 reagiert CF3SCl uber die Zwischenstufe Cl2Te(NSO)2 zur bekannten Verbindung Te2NCl5. Kondensierte man TeF4 mit [(CH3)3Si]2NH so bildete sich Tetrafluoroditelluradiazetidin, das mit (CH3)3SiCl in das entsprechende Chlorderivat umgewandelt wurde. Metathesen zwischen Cl2TeNSNS und CF3C(O)OAg fuhrten zu [CF3C(O)O]2TeNSNS. Analog liesen sich (CH3)2Te(NSO)2–xClx (x = 0,1) und (CH3)2Te(NSO)2 aus (CH3)2TeCl2 und AgNSO bzw. AgNCO herstellen. Die Halogenierung von Cl2Te(NSN)2TeCl2 mit Cl2 bzw. Br2 ergab Cl6TeN2S bzw. Cl4Br2Te2N2S. Letzteres bildete sich auch aus Cl2Te(NSO)2 und Br2. AgNSO wurde aus CF3C(O)OAg und (CH3)3SiNSO hergestellt. Zwei weitere Synthone (CF3Se)2Te und (CF3S)2Se konnten aus CF3SeCl und Na2Te bzw. Hg(SeCF3)2 und SeCl4 synthetisiert werden.

Perfluorinated Brønsted 'superacids': Powerful catalysts for the preparation of vitamin E

The key-step in the industrial synthesis of (all-rac)-a-tocopherol (synthetic vitamin E) is the condensation reaction of trimethylhydroquinone with the C 2 0 building block isophytol. For this Friedel-Crafts-type reaction, perfluorinated NH- and CH-acidic compounds (perfluoroalkyl(aryl)sulfonyl imides and methides) have been applied as excellent catalysts, preferably in biphasic solvent systems.

Bis(sulfinylamido)tellurium(IV) fluoride: a versatile synthon in tellurium–nitrogen chemistry

Abstract Halogen exchange reactions between F2Te(NSO)2 and Me3SiX provide X2Te(NSO)2 (X=Cl, Br). The brominated derivative can also be made from Te(NSO)2 and Br2 or from Te and BrNSO. Pyrolysis of F2Te(NSO)2 gives F 2 TeNSNS which reacts with MF5 to salt like [ F TeNSNS ] + [ MF 6 ] − (M=As, Sb). Halogenation of F2Te(NSO)2 with Cl2 or Br2, ratio 2:1, provides X2Te(NSN)2TeX2. The corresponding F2Te(NSN)2TeF2 is made by decomposition of F2Te(NSO)2 dissolved in THF at room temperature during 10 days. It can be transferred by Cl2, Br2 or Me3SiX, respectively to X2Te(NSN)2TeX2 (X=Cl, Br). When F2Te(NSO)2 is reacted with X2 in an 1:1 molar ratio or with TeX4, then the bicyclus X 2 TeX 2 Te ( X 2 ) N  S  N (X=Cl, Br) is formed. Ionic moieties with a cage type cation 5 are obtained by treating F2Te(NSO)2 (molar ratio 1:1) or F2Te (NSN)2TeF2 with MF5 (M=As, Sb) (molar ratio 1:2) in SO2 solution. A 1:1 mixture of F2Te(NSO)2 and MF5 reacts in CH2Cl2 giving [FTe(NSO)2]+[MF6−]. In SO2 solution, F2Te(NSO)2 reacted with AsF5, molar ratio 1:2, to [Te(NSO)2]++[AsF6−]2. Metathetical reactions between F2Te(NSO)2 and [CF3C(O)]2O or Me3Si-OC(O)CF3 as well as Me3SiOS(O2)CF3 yield the novel compounds [CF3C(O)O]2Te(NSO)2 and (CF3SO2O)2Te(NSO)2, respectively. X-ray structure for 9 is provided.