Volume 36, Issue 3

The title compounds were prepared and their crystal structures determined from low temperature single crystal X-ray data. The structures contain the anions SbCl 6 - and AlCL 4 - and the novel interhalogen cations I 3 Cl 2 + and I 3 Br 2 + . Anions and cations are linked to infinite chains by weak covalent bonds.

The reaction of [MoO 2 ((CH 3 )HN-O) 2 ] and N-methylhydroxylammoniumchloride in an aqueous suspension with CS 2 yields red crystals of the analytical composition MOC 4 H 14 N 3 O 4 S 2 . The crystal structure has been determined by single crystal X-ray diffraction analysis. The compound crystallizes in the monoclinic space group P2 1 /c, with cell constants a= 1333.2(3), b = 814.2(2), c = 2179.8(6) pm, β = 105.42(2)°, and Z = 8. The final R-value is 4.5% for 2965 unique reflexions. The structure consists of two crystallographically independent neutral complexes of molybdenum(VI). The geometry about the molybdenum is a distorted pentagonal bipyramid containing a terminal oxygen atom, two N-methylhydroxylamido(1-) ligands coordinated via the O-and N-atoms and an N-methyl-N-oxo-dithiocarbamato(2-) ligand forming a planar five membered ring with the molybdenum(VI) center (O,S-coordination).

The reaction of FeCl 3 with S 4 N 4 in CH 2 Cl 2 at room temperature yields S 6 N 4 2+ (FeCl 4 - ) 2 (A), among other products. Crystal data of A: Space group P2 1 /c, Z = 4, α = 12.090(4), b= 11.745(3), c= 13.918(3) Å, β= 101.25(2)°. In its dimensions and its conformation the S 6 N 4 2+ -cation in A agrees well with the S 6 N 4 2+ -cation in other salts. There exists one close S···Cl contact between each of the S atoms of the central S 4 ring in the cation and the neighbouring FeCl 4 - anions (3.04 to 3.16 Å; for comparison: the S···Cl van der Waals distance is 3.50 Å).

(Benzoyloxy)-and (pentafluorobenzoyloxy)diphenylphosphanes RC(O)OPPh 2 (2a, b) [R = C 6 H 5 (a), C 6 F 5 (b)] can be obtained by reaction of ClPPh 2 (1) with NaO 2 CC 6 H 5 and AgO 2 CCeF 5 , respectively [eq. (1)]. Oxidation of 2a with molecular oxygen yields (benzoyl-oxy)diphenylphosphane oxide (3a) [eq. (2)]. The complexes (OC) 5 CrPPh 2 OC(O)R (5a, b) are formed by the action of Na 2 OCC 6 H 5 and AgO 2 CC 6 F 5 , respectively on (OC) 5 CrPPh 2 Cl (4) [eq. (3)]. The chemical and spectroscopical properties of the (aroyloxy)diphenylphosphanes (2 a, b) are compared with the corresponding aryldiphenylphosphane oxides.

The electrochemical substitution of group VIB hexacarbonyls by solvent molecules and/or phosphane ligands is studied in some detail and is found to be a fruitful alternative preparative route to the well-known photochemical reaction.

The deprotonated glycolate dianion (OCH 2 CH 2 O) 2- is shown to react as a bidentate chelating ligand towards chalcogen(IV) halides. With TeCl 4 , the anion TeCl 3 (O 2 C 2 H 4 ) - is formed. According to a single crystal X-ray analysis of the tetraphenylphosphonium salt (P2 1 /c, a = 7.501, b = 26.328, c = 13.582 A, β= 104.55°, Z = 4) Te is in a tetragonal pyramidal (ψ octahedral) coordination with the alcoholate ligands in the apical (Te-O 1.919 Å) and in one of the equatorial positions (Te O 1.973 Å), the Te-Cl bond lengths being between 2.495 and 2.590 Å. The trans bond lengthening effect of the equatorial alcoholate ligand (i.e. the polarizing effect towards the lone pair) is unusually low. Vibrational spectra are reported.

Decaborane B 10 H 14 is formed by opening the B 10 H 10 2- cage in strong acidic medium. The reaction must be carried out in the presence of an inert solvent which dissolves B 10 H 14 . The best yields (28%) are obtained when zinc dust is added to the reaction mixture. The conversions of B 10 H 10 2- into B 10 H 14 or B 10 H 12 (Et 2 S) 2 probably obey the same mechanism.

Reactions of [(COD)RhCl] 2 (2) (COD = 1,5-cyclooctadiene) with i-C 3 H 7 MgBr in ether and styrene or o-methylstyrene lead to formation of the complexes [(COD)Rh(η 3 -7-methyl-benzyl)] (3) and [(COD)Rh(η 3 -6,7-dimethylbenzyl)] (4), respectively. 4 was characterized by X-ray analysis. With β-methylstyrene or allylbenzene [(COD)Rh(η 3 -7-ethylbenzyl)] (5) is formed; the latter case leads to precedent isomerisation of allylbenzene to β-methyl-styrene. On the other hand no η 3 -benzylrhodium complexes could be isolated by reactions of 2 with a-methylstyrene, 2,4-dimethylstyrene, 2,6-dimethylstyrene or 2,4,6-trimethyl-styrene. The steric reasons for this behaviour are discussed.

The compounds C 5 H 5 M[{P(OMe) 2 O} 2 H] and C 5 H 5 M[{P(OMe) 2 O} 2 ]Q (M = Ni, Pd; Q = NH 4 , Tl) react with metal acetylacetonates M'(acac) n and metal chlorides M'Cl n to give the tri-and tetranuclear complexes C 5 H 5 M[{P(OMe) 2 O} 2 ] n M' [n = 2 or 3; M' = Co(II), Cu(II), Zn(II), VO, Al(III), Cr(III), Fe(III)]. The mixed-ligand complexes [C 5 H 5 Ni{P(OMe) 2 O} 2 ] 2 Ni(NH 3 ) 2 , [C 5 H 5 Ni{P(OMe) 2 O}2]Ni(acac), [C 5 H 5 Pd{P(OMe) 2 O} 2 ]VO(acac), [C 5 H 5 M{P(OMe) 2 O}2]Pd(2-RC 3 H 4 ) (M = Ni, Pd; R = Me, Bu t ) and [C 5 H 5 Ni{P(OMe) 2 O} 2 ]Rh(C 8 H 12 ) are obtained following similar synthetic routes. Thermolysis of [C 5 H 5 Ni{P(OMe) 2 O} 2 ] 2 Ni(NH 3 ) 2 in vacuo leads to the trinuclear nickel complex [C 5 H 5 Ni{P(OMe) 2 O} 2 ] 2 Ni. The magnetic properties as well as the IR, NMR, UV and ESR spectra of the new organometallic chelate complexes are discussed.

125 Te NMR shifts and coupling constants 1 J( 125 Te 31 P) of various types of Te-P com-pounds have been measured. 125 Te NMR singlets from R 3 P = Te/PR 3 mixtures corroborate the rapid Te migration between tertiary phosphanes. Tellurophosphanes R-Te-PR′ 2 give well-resolved doublets (R = p·tolyl, trimethylsilyl) or triplets (R = PR' 2 ) due to 1 J( 125 Te 31 P) coupling. Coordination of tellurophosphanes to metal carbonyls via the lone pair at phosphorus leads to downfield shifts of the 125 Te NMR resonances.

The carbamoyl complex [(CO) 4 FeC(O)NMe 2 ][C(NMe 2 ) 3 ] (1) reacts with boron halides of the type BrBR 2 (R = Me, Ph, NMe 2 ) at low temperature to give the boroxycarben complexes 2, which decompose at ambient temperature to the aminoboranes 3 and Fe(CO) 5 . The 1 NMR and IR spectra of the new compounds 2 are reported.

The phenylogous enehydrazines 3 a-c prepared from the three isomeric benzenediamines 1 a - c and dimedone (2) were treated with the acetylenic esters 4a-b. While 3 c did not react under the applied conditions, 3 a, b gave the openchained products 5 a, b, 7 a, b, and 9 and, in one case, the ringclosed N-addition product 6 as well as the C-addition products which, however, cyclized to the corresponding quinoline-2,5-diones 8 a, b and 10. In compound 11 both reaction types were realized.

3,3-Bis(trifluoromethyl)-2,2,2-trimethoxy-2,2-dihydro-1,4,2-oxazaphosphol-4-enes (1) on thermolysis undergo a 5→[3 + 2]cycloreversion reaction with formation of trifluoro- methyl substituted nitrile ylides (2). The latter dimerize to produce 3,6-diazaocta-2,4,6- trienes (3a, 6) which may react further to yield 6,12-dihydro-dibenzo[c,h][1,5]naph- thyridines (10), and syn/anti 4-ethylimino-1,4-dihydroisoquinolines (12/13). The naphthyridines (10) on treatment with cone. KOH are transformed into 3,3'-bis(1H-isoindoles) 11. Lithium aluminium hydride reduction of the 4-ethylimino-1,4-dihydroisoquinolines (12/13) yields 4-ethylimino-1,2,3,4-tetrahydroisoquinolines (14). A reaction mechanism for the 1,3-dipole dimerization of bis(trifluoromethyl)substituted nitrile ylides is discussed.

3,3-Bis(chlorodifluoromethyl)-2,2,2-trimethoxy-2,2-dihydro-1,4,2-oxazaphosphol-4-enes (2) at room temperature, 3,3-bis(chlorodifluoromethyl)-2,2,2-triphenoxy-2,2-dihydro-1,4,2-oxazaphosphol-4-enes (3) at 140-145 °C undergo cycloelimination of trimethyl, and triphenyl phosphate, respectively, with formation of N-[1-chlorodifluoromethyl-2,2-di-fluoro(vinyl)]-imidoyl chlorides (4) in high yields.

The oxidation of tryptophan to 3-indoleacetaldehyde with sodium hypochlorite was investigated with 14 C labelled DL-tryptophan. The reaction was performed under pseudo first order conditions. From the pH dependence of the reaction it was concluded that only the unprotonated tryptophan is converted to the aldehyde. The activation energy is 35 ± 2.2 (SE) kJ x mol -1 as derived from the Arrhenius plot. Variing the pH between 8.5 and 11.0 and the temperature in the range from 298 K to 318 K did not alter the selectivity of the reaction as confirmed by TLC of the product (purity ≧ 90%). A possible reaction mechanism is proposed.

13-Substituted naphthene(K 1)xanthene(or thioxanthene)-1,4-dione (4a, b) have been obtained by thermal cycloaddition of p-benzoquinone (2) to 9-vinylidenexanthene(or thioxanthene) derivatives (1 a, b). Reductive acetylation of 4 gives the diacetoxy deriv­atives. Compound 4 acting as dienophile, react with 1 or with 1,1-di(p-methoxyphenyl) ethylene (6) to give diadducts. 1,4-Naphthoquinone (10) reacts similarly with 1 to give 14-substituted anthracene(K 1)xanthene(or thioxanthene) 5,15-diones (11a, b). Com­pounds 1 a, b also react with N-phenylmaleimide (12) to give the diadducts (3a, 3b, 4, 6a, 12, 12a) hexahydro-12-phenyl-N-phenylphthalimido(K 1)xanthene (or thioxanthene) 4-6a-N-phenylpyrrolidine-r,3'-diones (13) or aromatized monoadducts 12-substituted-N- phenylphthalimide (K1) -xanthene (15 a, b).

Treatment of 5-arylidene-2-methylmercaptohydantoins (1a-d) and 5-arylazo-2-methyl- mercaptohydantoins (3a, b) with glycine in acetic acid gave 5-arylidene-N 2 -carboxy- methylglycocyamidines (2a-d) and 5-arylazo-N 2 -carboxymethylglycocyamidines (4a, b) respectively. 2 a, b, d were cyclised with acetic anhydride to give imidazoimidazoline derivatives (5a-c). 2-Methylmercapto-3-phenylhydantoin (7) reacted with anthranilic acid to give 9 which previously prepared by the action of aniline on ethyl 2-methylthio-4-oxo- 3,4-dihydro-3-quinazolinylacetate (8). Arylidenes 1 a-c, 10 a-c and arylazo derivatives 3 a, b reacted with anthranilic acid to give imidazoquinazoline derivatives 11a-f and 12 a, b, respectively.

The desulfurization of several naturally occurring sulfur-containing amino acids by Raney nickel was studied under various conditions. Raney nickel, which was prepared by treating Al-Ni alloy with 5 N NaOH at 60 °C for 30 min, and was not washed with water, was most active and desulfurized, in quantitative yield, methionine, homocysteine, homocystine, homocysteine sulfinic acid, S-(2-carboxy-n-propyl)-L-cysteine, cysteine, cystine, cysteine sulfinic acid and S-methylcysteine sulfoxide. Raney nickel prepared from 100 mg of Al-Ni alloy desulfurized quantitatively up to 40 μmol methionine at 60 °C for 30 min. The desulfurization occurred effectively in the pH range of 7 and 13, but not below 7. Methionine sulfone, cysteic acid, and homocysteic acid were not subject to the reaction. The Raney nickel was deactivated by H 2 S, and H 2 O 2 , or combustion. Desulfurization activity was not enhanced by hydrogen gas.

Various azulene derivatives as a new type of coloured liquid crystals have been synthesized. Their mesomorphic behaviour is described.

The structure of several esters of 8-epi-desoxymaytol has been elucidated.

Wittig reactions of imidazole-2- and 4(5)-carboxaldehyde yield the compounds 3 and 4. These vinyl ketones react with N,N-dimethylformamide-dimethylacetal to produce the eneamino-ketones 5 and 6, which are converted into the imidazo-azepine-7-ones (7) and 8.

The electrochemical oxidation and reduction properties of different dihydropyridines and pyridines have been investigated in non aqueous solvent as benzonitrile and aceto-nitrile with tetra-n-butylammonium perchlorate as supporting electrolyte at platinium electrodes using DC-voltametry, cycl. voltametry and coulometry. Possible redox-mechanisms are discussed.

The results of a kinetic study on the hydrogen transfer between different dihydropyridines and mono-, bis-and trishydrazyls of the tricyanobenzene series are described. The reactions have been found to obey in all cases a second-order law. The influences of solvent medium, redox-potentials of the reactants and temperature on the rates of reactions have been investigated.

RuO 4 can be obtained from Ru metal and ozone at room temperature. This procedure yields pure RuO 4 directly, and there are no problems of separation from water as in standard methods of preparation.

Metal dithiolenes and other sulfur containing metal complexes catalyse the photoproduction of hydrogen from water in the presence of tetrahydro-or dihydrofurans.

One-bond, geminal and vicinal 13 C, 1 H coupling constants have been determined for 2-methyl-and 3,5-dimethyladamantane using the derivatives deuterated in position 2 and 1, respectively, and the relation n J( 13 C, 1 H) = 6,5144 n J( 13 C, 2 H) for the conversion of the measured n J( 13 C, 2 H) values. The effect of methyl-substitution on these parameters is discussed.

An ability of azolyl-anions to behave as one-electrons reductans in reactions with f-nitro-sobutane and iron carbonyls are found in solu-tions. The azolyl radicals formed in reaction of azolyl-anions and azoles with t-BuNO have been trapped as corresponding nitroxide radicals. The formation of radicals from azoles can be described as consequence of proton and electron transfer acts.

Methoxymercuration-demercuration, Pheromones Methoxymercuration-demercuration of alkenyl acetates and alkenols yields methoxyderivatives which were analysed by mass spectrometry to determine the original double bond position.