Synthesis of benzo-1,3-ditellurole and its precursors

Poly(o-phenyleneditelluride) 6 has been prepared by the reduction of 1,2-bis(trichlorotelluro)benzene obtained by treatment of 1,2-bis(trimethylsilyl)benzene with TeCl₂. The reduction of 6 with NaBH₄ in ethanol solution affords sodium benzene-1,2-ditellurolate, which, upon treatment with methylene bromide, forms benzo-1,3-ditellurole in 40–47% yield. Benzo-1, 3-ditellurole has also been synthesized in 18–20% yeild by the reaction of 1,2-bis(trimethylslyl)benzene with bis(trichlorotelluro)methane, with subsequent reduction of the product, 1,1,3,3-tetrachlorobenzo-1,3-ditellurole.     

Benzo-1,3-ditellurolium tetrafluoroborate

Interaction of disodiumo-benzeneditellurolate with butyl dichloromethyl ether gave 2-butoxybenzo-l,3-ditellurole. Treatment of the latter with HBF₄ in acetic anhydride afforded benzo-1,3-ditellurolium tetrafluoroborate.Translated fromIzyestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 387–388, February, 1993.     

Thermal Decomposition of New Mononuclear NiII Complexes with ONNO Type Reduced Schiff Bases and Pseudo Halogens

Mononuclear nickel(II) complexes were prepared by reaction of the three ONNO type reduced Schiff bases bis‐N,N′‐(2‐hydroxybenzyl)‐1,3‐propanediamine (L^HH₂), bis‐N,N′‐(2‐hydroxybenzyl)‐2,2′‐dimethyl‐1,3‐propanediamine (LDM^HH₂), and bis‐N,N′‐[1‐(2‐hydroxyphenyl)ethyl]‐1,3‐propanediamine (LAC^HH₂) with Ni^II ions in the presence of pseudo halides (OCN^–, SCN^– and N₃^–). The complexes were characterized with the use of elemental analyses, IR spectroscopy, and thermal analyses. The molecular structure of one of the complexes was obtained by single‐crystal X‐ray diffraction. The obtained complexes are mononuclear, and a pseudo halide molecule is attached. One of the oxygen atoms of the ligand is in phenolate and the other was in phenol form. According to the thermogravimetry results, it was thought that the pseudo halide thermally detaches from the structure as hydropseudo halide. In azide‐containing complexes an endothermic reaction was observed although the azide group usually decomposes with an exothermic reaction.     

Synthesis of the first 1,3-ditellurole-containing radialene-type TTF derivatives

[reaction: see text] The first synthesis of dendralene-type TTF derivatives bearing a 1,3-ditellurole ring has been achieved. Preliminary electrochemical results are presented.     

Rh2(oac)4-catalyzed reactions of methyl diazoacetate with 1,3-oxazolidines and 1,3-oxathiolanes

Methoxycarbonylcarbene generated by catalytic decomposition of methyl diazoacetate in the presence of Rh₂(OAc)₄, is regioselectively inserted into the C(2)-O bond of 3-alkyl-2-phenyl-1,3-oxazolidines and into the C(2)-S bond of 2-phenyl-1,3-oxathiolane. Study by the competitive reaction method demonstrated that the relative reactivity toward the insertion of the methoxycarbonylcarbene fragment into the C-heteroatom bond increases in the series of 1,3-dioxolane, 1,3-oxazolidine, and 1,3-oxathiolane. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1411–1415, August, 2006.     

Asymmetric Diels-Alder Reactions of Cyclopentadiene with N-Crotonoyl- and N-Acryloyl-4,4-Dimethyl-1,3-Oxazolidin-2-one,Mediated by Chiral Lewis Acids

One-pot Diels-Alder reactions of cyclopentadiene with 3-crotonoyl- ( 2 ) and 3-acryloyl-4,4-dimethyl-1,3-oxazolidin-2-one ( 3 ), Mediated by chiral Lewis acids, are described. AlCl₃, EtAlCl₂, Et₂AlCl, TiCl₄, ZrCl₄, SnCl₄, SiCl₄, and BBr₃, modified with derivatives of D -mannitol, L -tartaric acid, and (R)-binaphthol, were applied as chiral promotors. The reaction with dienophile 2 , carried out in CH₂Cl₂ at ?78° with high yield, was characterized by excellent π-face selectivity. In case of the reaction with dienophile 3 , the efficiency of the chirality transfer was much lower.     

A 1D coordination polymer {Pb[C6H4(COO)2][phen]} n with strong blue fluorescent emission

The hydrothermal reaction of 1,3-dicyanobenzene, 1,10-phenanthroline (phen) and Pb(CH₃COO)₂ yields a new 1D coordination polymer, {Pb[C₆H₄(COO)₂][phen]} _n . The 1,3-benzenecarboxylate anion found in the final product was generated in situ during the synthesis by hydrolysis of 1,3-dicyanobenzene. X-ray diffraction shows that complex 1 crystallizes in the triclinic system, space group P 1, a?=?7.5442(2)?Å, b?=?9.7962(3)?Å, c?=?13.1505(4)?Å, α?=?69.739(2)?Å, β?=?80.597(2)?Å, γ?=?71.377(2)?Å, v?=?862.48(4)?ų, Z?=?2, D _c?=?2.124 Mg?m^?3. Complex 1 emits strong blue fluorescent light (λem(max)?=?482.4?nm) when excited by UV light in the solid state at room temperature.     

Catalytic Cycloaminomethylation of Aminobenzamides with 1,3-Bis[dimethylamino(methoxy)methyl]thiourea

Efficient methods of the synthesis of cyclophanes containing the thiourea moiety via the reaction of o-, m-, and p-aminobenzamides with 1,3-bis(dimethylaminomethyl)thiourea or 1,3-bis(methoxymethyl)thiourea using NiCl₂·6H₂O and SmCl₃·6H₂O as catalysts have been developed.

     

Zum Mechanismus der Reduktion von 1,3-Benzodithiol-2-thionen

Carbophilic reaction of 1,3-benzodithiole-2-thione (1) with trideuteroborane · dimethylsulfide, synthesized from NaBD₄ and BF₃ ·Me ₂S inTHF, gave 2,2-dideutero-1,3-benzodithiole (5 b) as well as the minor side-products7 b,8 and9 b.

     

Toward molecular wire: Synthesis,crystal, molecular,and π-electronic structure of 1,7-bis(aryl)-1,3,5,7-tetraaza-2,4,6-trithia-1,2,5,6-heptatetraenes

The title compounds were obtained by the reaction of 1-aryl-3-trimethylsilyl-1,3-diaza-2-thiaallenes with dichloromonosulfane or 1-aryl-4-(1-phtalimidyl)-1,3-diaza-2,4-dithia-1,2-butadienes in the presence of CsF. The latter route also afforded nonsymmetric derivatives. In contrast, the reaction of N,N,N′,N′-tetrakis(trimethylsilyl)diaminosulfane with S,S-dichloro-N-aryliminosulfuranes (1:2) led to 1,3-bis(aryl)-1,3-diaza-2-thiaallenes and cyclotetra(azathiene). As shown by the X-ray structure analysis, the molecule of the title compound with Ar = Ph is planar, with configuration of the azathiene chain being similar to that of poly(azathiene) (SN)_x. The MNDO calculations indicate that most of the π-MOs of this compound, including the frontier ones, are delocalized throughout the whole molecule. The data obtained confirm the possibility of creating molecular wire for molecular electronic devices on the basis of extended acyclic azathienes. An attempt to synthesize more extended compounds than the title ones resulted in spontaneous shortening of their azathiene chains.     

Synthesis of 3‐(ω‐Hydroxyalkoxy)isobenzofuran‐1(3H)‐ones by Trifluoroacetic Acid‐Mediated Lactonization of tert‐Butyl 2‐(1,3‐Dioxol‐2‐yl)‐ or 2‐(1,3‐Dioxan‐2‐yl)benzoates

An efficient two‐step method for the preparation of 3‐(2‐hydroxyethoxy)‐ or 3‐(3‐hydroxypropoxy)isobenzofuran‐1(3H)‐ones 3 has been developed. Thus, the reaction of 1‐(1,3‐dioxol‐2‐yl)‐ or 1‐(1,3‐dioxan‐2‐yl)‐2‐lithiobenzenes, generated in situ by the treatment of 1‐bromo‐2‐(1,3‐dioxol‐2‐yl)‐ or 1‐bromo‐2‐(1,3‐dioxan‐2‐yl)benzenes 1 with BuLi in THF at ?78°, with (Boc)₂O afforded tert‐butyl 2‐(1,3‐dioxol‐2‐yl)‐ or 2‐(1,3‐dioxan‐2‐yl)benzoates 2 , which can subsequently undergo facile lactonization on treatment with CF₃COOH (TFA) in CH₂Cl₂ at 0° to give the desired products in reasonable yields.     

Unkatalysierte sigmatrope 1,5-Wanderung von Acylgruppen bei der Thermolyse von 5-Acyl-5-methyl-1,3-cyclohexadienen

Uncatalyzed Sigmatropic 1,5-Shift of Acyl Groups in the Thermolysis of 5-Acyl-5-methyl-1,3-cyclohexadienes Four different 5-acyl-5-methyl-1,3-cyclohexadienes 1a–d (R = COOCH₃, COCH₃, COC₆H₅, CHO) have been shown to yield mixtures of 1,3-disubstituted cyclohexadienes 2–7 and 1,3-disubstituted aromatic product 8 upon thermolysis at 150–300° in solution and at 350–500° in the gas phase in a flow system. Two reaction pathways (A and B in Scheme 2) are considered for the rearrangement of the C-Skeleton. For the ester 1a ¹³C-isotopic substitution shows that products arise to 75–86% through a 1,5-sigmatropic shift of the methoxycarbonyl group ( A in Scheme 2) and to 14–25% through a sequence of reaction steps involving a 1,7-H-shift reaction in an acyclic intermediate ( B in Scheme 2). For the more reactive compounds 1b–d isomerization is assumed to follow the 1,5-sigmatropic pathway exclusively ( A in Scheme 2). A kinetic study yields the following sequence for the migration tendency of acyl groups toward sigmatropic 1,5-shift: COOCH₃ < COCH₃ < COC₆H₅ < CHO.     

Carbenoid Reactions of Dimethyl Diazomalonate with Aromatic Thioketones and 1,3-Thiazole-5(4H)-thiones

Dimethyl diazomalonate ( 4 ) and thiobenzophenone ( 2a ) do not react in toluene even after warming to 50°. After addition of catalytic amounts of Rh₂(OAc)₄, a smooth reaction under N₂ evolution afforded a mixture of thiiranedicarboxylate 5 and (diphenylmethylidene)malonate 6 (Scheme 2). A reaction mechanism via an intermediate ‘thiocarbonyl ylide’ 7 , formed by the addition of the carbenoid species 8 to the S-atom of 2a , is plausible. Similar reactions were carried out with 9H-xanthene-9-thione ( 2b ), 9H-thioxanthene-9-thione ( 2c , Scheme 4), and 1,3-thiazole-5(4H)-thione 18 (Scheme 6). In the cases of 2b and 2c , spirocyclic 1,3-dithiolanetetracarboxylates 14a and 14b , respectively, were obtained as the third product. Reaction mechanisms for their formation are proposed in Scheme 5: S-transfer from intermediate thiirane 12 to the carbenoid species yielded thioxomalonate 15 which underwent a 1,3-dipolar cycloaddition with ‘thiocarbonyl ylide’ 16 . An alternative is the formation of ‘thiocarbonyl ylide’ 17 via carbene addition to 15 , followed by 1,3-dipolar cycloaddition with 2b and 2c , respectively.     

Synthesis and Tautomeric Equilibrium of Polyfluoroacyl-Containing 1,5-Benzodiazepines

The reaction of bis(polyfluoroalkyl)-containing 1,3,5-triketones with o-phenylenediamine yielded 2-polyfluoroacylmethylene-4-polyfluoroalkyl-1,3- or 1,5-dihydro-1,5-benzodiazepines. The tautomeric equilibrium of the obtained benzodiazepines in CDCl₃, CD₃CN, DMSO, and DMF solution was studied.     

Aqueous-Mediated green synthesis of novel spiro[indole-quinazoline] derivatives using kit-6 mesoporous silica coated Fe3O4 nanoparticles as catalyst

In this work, a series of eight new spiro[3,4′]1,3-dihydro-2H-indol-2-one-2′-amino-4′,6′,7′,8′-tetrahydro-2′,5’(1’H,3’H)-quinazoline-diones were successfully synthesized through a three-component reaction of 1H-indole-2,3-diones (isatins), guanidine nitrate, and 1,3-cyclohexanediones, by use of Kit-6 mesoporous silica coated Fe₃O₄ nanoparticles (Fe₃O₄@SiO₂@KIT-6) as a highly efficient magnetically separable nanocatalyst in aqueous media at 60°C. Several notable features of thiseco-friendly protocol are high yields of products, short reaction times, operational simplicity, and the use of easily available and recyclable catalyst.     

Synthesis and Tautomeric Equilibrium of Polyfluoroacyl-Containing 1,5-Benzodiazepines

Summary. The reaction of bis(polyfluoroalkyl)-containing 1,3,5-triketones with o-phenylenediamine yielded 2-polyfluoroacylmethylene-4-polyfluoroalkyl-1,3- or 1,5-dihydro-1,5-benzodiazepines. The tautomeric equilibrium of the obtained benzodiazepines in CDCl₃, CD₃CN, DMSO, and DMF solution was studied.     

Synthesis of Some Selectively N-Protected (1S,2S)-p-Nitrophenylserinol–Based Diamino-1,3-dioxanes and Tripodands

The unconventional methodology for the non-epimerizable cycloacetalization of optically active (1S,2S)-2-amino-1-(4-nitrophenyl)propane-1,3-diol (p-nitrophenylserinol) (condensed H₂SO₄ 96% as solvent and catalyst, i.e., sulfuric transacetalization) producing (2R,4S,5S) diamino-1,3-dioxanes was enlarged by the use of N-protected forms of 2,2-dimethoxyethylamine (DMEA, aminoacetaldehyde dimethylacetal). Conversely, N-protected derivatives of p-nitrophenylserinol were successfully cyclocondensed with DMEA in the same sulfuric conditions. N-Functionalization of DMEA upon treatment with trimesic acid trichloride and cyanuric chloride yielded the corresponding triple amide and melamine, respectively. Their adapted sulfuric transacetalization in triplicate in reaction with arylserinols (aryl: phenyl, p-nitrophenyl) afforded a new series of optically active tripodands.     

Co<Superscript>II</Superscript> and Rh<Superscript>I</Superscript> complexes with <Emphasis Type="Italic">C</Emphasis><Subscript>2</Subscript>-symmetric chiral diamines of the dioxolane series

The reaction of di-μ-chlorobis(1,5-cyclooctadiene)dirhodium with (4S, 5S)-2,2-dimethyl-4,5-bis(methylaminomethyl)-1,3-dioxolane (1) gave the complex [Rh(cod)(1)]Cl (cod is 1,5-cyclooctadiene). The composition of the complexes CoCl₂ · L₂ and [Rh(cod)(L₂)]X (L₂ = 1, (4S,5S)-2,2-dimethyl-4,5-bis(aminomethyl)-1,3-dioxolane, and (4S, 5S)-2,2-dimethyl-4,5-bis(dimethylaminomethyl)-1,3-dioxolane; X = Cl, TfO) was studied using IR and ¹H NMR spectroscopy. In the Rh^I cyclooctadienediamine complexes, the diene molecule forms a stronger bond with the metal atom than that in the cyclooctadienediphosphine analogs. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2270–2274, October, 2005.     

Synthesis of 1,3‐Selenazol‐2(3H)‐imines

The reaction of N,N′‐diarylselenoureas 16 with phenacyl bromide in EtOH under reflux, followed by treatment with NH₃, gave N,3‐diaryl‐4‐phenyl‐1,3‐selenazol‐2(3H)‐imines 13 in high yields (Scheme 2). A reaction mechanism via formation of the corresponding Se‐(benzoylmethyl)isoselenoureas 18 and subsequent cyclocondensation is proposed (Scheme 3). The N,N′‐diarylselenoureas 16 were conveniently prepared by the reaction of aryl isoselenocyanates 15 with 4‐substituted anilines. The structures of 13a and 13c were established by X‐ray crystallography.     

Synthesis,Characterization, and Crystal Structure of 1,3‐Dipentafluorophenyl‐2,2,2,4,4,4‐hexazido‐1,3‐diaza‐2,4‐diphosphetidine

1,3‐Dipentafluorophenyl‐2,2,2,4,4,4‐hexazido‐1,3‐diaza‐2,4‐diphosphetidine ( 1 ) was synthesized by the reaction of [(C₆F₅)NPCl₃]₂ with trimethylsilyl azide in CH₂Cl₂ and characterized by multinuclear NMR and vibrational spectroscopy. The molecular structure of the compound was determined by single‐crystal X‐ray structure analysis. [(C₆F₅)NP(N₃)₃]₂ crystallizes in the monoclinic space group P2₁/n with a = 9.6414(2), b = 7.4170(1) and c = 15.9447(4) Å, β = 94.4374(9)°, with 2 formula units per unit cell. The bond situation in [(C₆F₅)NP(N₃)₃]₂ has been studied on the basis of NBO analysis. The antisymmetric stretching vibration of the azide groups is discussed. The structural diversity of 1 and 1,3‐diphenyl‐2,2,2,4,4,4‐hexazido‐1,3‐diaza‐2,4‐diphosphetidine in solution and in the solid state depending on the aryl substituent at the nitrogen atom is discussed.