Showing papers in "Mendeleev Communications in 1993"

TL;DR: In this paper, the reaction of ethylmagnesium bromide with ethyl acetate in the presence of styrene and titanium(IV) isopropoxide as a catalyst leads to (Z)-1-methyl-2-phenylcyclopropanol in 42% yield.

TL;DR: The d-election transition metal-substituted heteropolytungstate sandwich complex [(Fe II ) 4 (B-PW 9 O 34 ) 2 ] 10−, unlike PW 12 O 40 3− and most polytungstophosphates, is quite stable with respect to solvolysis by H 2 O 2 and catalyses the selective homogeneous epoxidation of alkenes in aqueous acetonitrile at 20°C by this oxidant as mentioned in this paper.

TL;DR: Pseudorotation of the singlet cyclopentadienyl cation (a C2v, "ethylene" type structure 2) proceeds through the "allylic" type C 2v singlet 3 as the transition state with an extremely low barrier [0.09] kcal mol 1 at MP4SDTQ/6-31G(2d,p)//MP2(full)/6-13G* as discussed by the authors.

TL;DR: A pernitrofuroxan was synthesized for the first time in this paper, and nucleophilic substitution studies show that this compound can be used as a starting material for the synthesis of 4-functionally substituted 3-nitro furoxans not hitherto readily accessible.

TL;DR: In this article, a trans-1,2,3-tricyanocyclopropane was obtained in the presence of NaBr in acetone or acetonitrile in the undivided cell.

TL;DR: In this article, a CO 2 /H 2 (1:1) mixture was placed in contact with a suspension of copper/zirconium polyhydride, Cu 3 Zr 2 H n, in an alcohol-benzene solution; the absence of CO and CH 3 OH among the reaction products in the ethanol homologation suggests that carbon monoxide and methanol are not involved in the reaction observed.

TL;DR: In this article, a general approach to Namination of pyrazoles, allowing the synthesis of previously inaccessible N -aminopyrazoles with electron-acceptor substituents in the ring, has been proposed, consisting of treatment of the pyrazole with hydroxylamine-O -sulfonic acid in aqueous media at controlled pH depending on p K a of the p

TL;DR: The influence of the pretreatment temperature of zeolites on their activity in oxidation of benzene to phenol using N2O has been investigated in this article, where it was found that hydrogen sulfoxide (HZSM-5) dehydroxylation led to a significant increase in phenol yield over these zeolite.

TL;DR: The aggregation pheromone component of rusty grain beetle Cryptolestes ferrugineus, ferrulactone II, has been synthesized based on Wittig reaction of the title phosphonium salt with (S )-8-tetrahydropyranyl)oxynonanal readily available, in turn from ( S )-methyloxirane.

TL;DR: For the first time, fullerene C 60 has been used in capillary gas chromatography and its ability towards dispersive interactions has been measured; a C 60 column has potential in the analysis of organic compounds as discussed by the authors.

TL;DR: In this article, the systems MeCOBr·nAlBr3 as well as CHBr3·n alBr3 and CCl4·n AlBr3 (n = 1-4.5) have been shown to initiate carbonylation of cyclopentane under mild conditions to give, after alcoholic work-up, the corresponding ester ofcyclopentylcarboxylic acid with good yields and high selectivity.

TL;DR: In this paper, the nitration of activated carbonyl compounds in a two-phase system gives novel possibilities for the synthesis of functional nitro derivatives, such as functional carbonyls.

TL;DR: In this article, it was shown that in reductive condensation of trichloromethylarenes with hydroxylamine and hydrazines in pyridine, the reduction stage, involving the exchange of one chlorine atom for a hydrogen atom, can proceed without participation of either hydrizine or hydrazine.

TL;DR: In this paper, a new method was developed for the synthesis of 5,6-dihydropyridin-2(1 H )-ones by cyclization of N -3-oxoalkylamides in the presence of bases.

TL;DR: In this paper, the reaction between tetraphenylphthalonitrile and phthalonitriles in the presence of copper(I) chloride gives a non-statistical mixture of phthalocyanines from which the tetrahenyl-substituted compound 3 can be isolated.

TL;DR: A general scheme for the synthesis of azolium and azinium dinitromethylides, by nitrating N- acetonyl derivatives of aromatic N -heterocycles with sulfuric acid/nitric acid mixtures, has been developed as mentioned in this paper.

TL;DR: In the presence of metal fluorides CF 3 OOC(O)F oxidizes internal perfluoroazaalkenes forming the coresponding oxaziridines in high yields as discussed by the authors.

TL;DR: An attempt to determine the absolute values of partial quadrupole splittings by investigating trigonal-prismatic low-spin iron(II) complexes has been made; all PQS values obtained are positive as mentioned in this paper.

TL;DR: Bis( N -alkylsalicylaldiminato)zinc and the beryllium(II) complexes as discussed by the authors display photochromic behavior in solution, while undergoing thermally-irreversible photocoloration reactions in bulky amorphous films.

TL;DR: Rhodium hydride HRh(CO)(PPh3)3 reacts with fullerenes C60 and C70 yielding (η2-Cn)RhH(CO)2 (n = 60,70) complexes whose composition and configuration have been established by means of IR and NMR spectroscopy as mentioned in this paper.

TL;DR: Crown thioethers, 1,4,8,11-tetrathiacyclotetradecanes and 1, 4, 8, 11,15,18hexathiaheneicosanes, have been synthesized as 2:2 and 3:3 cycloadducts in a "one-pot" homolytic macrocyclization of alkynes with propane-1,3-dithiol as mentioned in this paper.

TL;DR: In this article, the authors show that selectivity shifts from formaldehyde to ethane with oxygen pressure and temperature variation in methane oxidation over phosphate catalysts are evidence for the existence of mutual intermediate and different product selectivities over different catalysts under the same reaction conditions, indicating the participation of the surface in formaldehyde formation.

TL;DR: Two methods for the generation of nitro formonitrile oxide (NFNO) have been proposed: dehydration of dinitromethane and nitration of 1-nitro-2-methylprop-1-ene; NFNO has been identified in the form of its cyclodimerization product, dinitrofuroxan (DNFO).

TL;DR: The first derivatives of pyrazolo[3,4-c]furazan N-oxide have been synthesized from the corresponding 3-amino-4-(hydroxyiminomethyl) furazan by treatment with bromine followed by DBI as discussed by the authors.

TL;DR: In this article, photoelectron injection from mercury into aqueous electrolyte solution (PIMES) was used to determine the decay rates of polyfluorobenzoates and the redox potentials of radical anion decay products.

TL;DR: In this paper, a new synthesis of 3-amino-4,5,6,7-tetrahydro-indole and -benzo[b ]thiophene derivatives, based on Thorpe-Ziegler cyclization, is described.

TL;DR: Ion exchange interaction of a single-layer dispersion, prepared by hydration of LiMoS2, with transition metal salts leads to new intercalation compounds of molybdenum disulfide with these metal cations as mentioned in this paper.

TL;DR: O-FIuorosulfonyl-N,N-difluorohydroxylamine interacts with NH-azoles in an alkaline medium, affording the corresponding N-fluorosoundonylazoles and in certain cases also the products of their further reactions, N,N' -sulfonylbisazoles.

TL;DR: Rhodium(II) compounds are effective catalysts for the hydroboration of alkenes by catecholborane under mild conditions;regioselectivity is dependent on the catalyst, and a facile rhodium hydride catalysed olefin isomerization has been identified as mentioned in this paper.

TL;DR: In this paper, a series of 1,2-anionotropic rearrangements in the corresponding "ate"-complexes are presented for the transformation of THF-1-boraadamantane 1 into 1-(1-hydroxyethyl)adamantsane 5 and the hydrochioride salt of 1-( 1-aminoethyl)addamantanes (rimantadine) 9, respectively.