Die Schwingungsspektren der isomeren Komplexe N,N′-Bis(dimethylgallium)-cis- und trans-N,N′-dimethyloxamideine kritische Analyse

Reaction of Ga(CH₃)₃ with N,N′-dimethyloxamide affords two isomeric N,N′-bis(dimethylgallium)-N,N′-dimethyloxamide complexes, characterized by crystal structure analysis as having cis-and trans-configuration with respect to the central oxamide CC bond and belonging to the point groups C_2v (cis) and C_2h (trans), respectively. Both isomers which are formed in varying ratio, depending upon the reaction conditions, have been isolated in pure form; their vibration spectra (IR/RE) are analyzed in detail in points of alternative behaviour, and are assigned in all bands, especially in the G-C and Ga-X frequency region. The assignment receives further confirmation from a comparison with the vibrational data of the homologous N,N′-bis(dimethylgallium)oxamide (cis/trans isomer mixture).     

Preparation of N-carbomethoxyaminopyrroles

Azoalkenes $\text{1}$ react with enamines and β-dicarbonyl compounds to give $\text{N}$-carbomethoxyaminopyrroles rather than $\text{N}$-carbomethoxy-1,2-dihydropyridazines.     

Reaction between N-acyl-2,3-dihydrobenzo-1,4-thiazine and N-acylphenothiazine with organometallic reagents

the title $\text{N}$-acyl-derivatives react with $\text{n}$-BuLi and Grignard reagents leading to products, which, formally, can be considered as derived from a Claisen-type condensation reaction.     

N-methyl-N-anilinomethyl diphenylphosphine oxide: a versatile reagent for the synthesis of enamines

Cyclic as well as acyclic ketones, both saturated and α,β-unsaturated, can be converted into their homologous enamines by Horner-Wittig reaction with $\text{N}$-methyl-$\text{N}$-anilinomethyl diphenylphosphine oxide ($\text{3}$).     

Palladium catalysed synthesis of N and S heterocyclic esters

Palladium catalysed alkoxycarbonylation of heterocyclic halides affords a simple and versatile synthesis of both $\text{N}$ and $\text{S}$ heterocyclic esters where a range of catalysts have been studied and a method to employ inexpensive inorganic bases has been found.     

Photocycloaddition of N-methylthiophthalimide with alkynes

$\text{N}$-Methylthiophthalimide undergoes photochemical cycloaddition reactions with diphenylacetylene, hex-3-yne and bis(methylthio)acetylene to form spiro-thietes; in solution the spiro-thiete from the bis(methylthio)alkyne is in equilibrium with its ring-opened isomer.     

Rotational isomerism between the E and Z forms of o-substituted benzo-N-methyl hydroxamic acids in strong acid

The $\text{E}$∠$\text{Z}$ equilibrium of the cations of benzo hydroxamic acids, in mineral acid, was studied utilizing ¹H NMR spectroscopy, NOEDS and MNDO claculations     

O- versus N-methanesulphonylation and N-(methanesulphonyl)-methanesulphonylation with methanesulphonyl chloride

Depending upon the experimental conditions, t-butyl (1$\text{SR}$,5$\text{SR}$,7$\text{RS}$,8$\text{RS}$)-1-ethoxycarbonyl-8-hydroxy-2-oxa-6-azabicyclo[3.2.0]octane-7-carboxylate (2a) reacts with methanesulphonyl chloride to give predominantly the $\text{O}$-methanesulphonyl derivative (2b), the $\text{N}$-methanesulphonyl derivative (3a), or the $\text{N}$-(methanesulphonyl)methane-sulphonyl derivative (6a).     

Stereocontrolled (E,Z and erythro, threo) synthesis of ⊙-hydroxyallylic sulphides

All four isomers of substituted 3-alkylthio-4-hydroxybutenes have been synthesised: both the geometry of the double bond and the relative stereochemistry of the two chiral centres are controlled.     

The ipso-nitration of p-cresol

The nitration of $\text{p}$-cresol by nitric acid in aqueous sulphuric acid involves ~40% $\text{ipso}$-substitution at C^Me. The 4-methyl-4-nitrocyclohexa-2,5-dien-1-one (I) formed undergoes an acid-catalysed rearrangement to 4-methyl-2-nitrophenol.     

New highly oxidized fusicoccane diterpenoids from the liverwort plagiochilaacanthophylla subsp. japonica

Four novel fusicoccane diterpenoids, fusicoplagins A, B, C, and D, have been isolated from the liverwort $\text{Plagiochila}$$\text{acanthophylla}$ subsp. $\text{japonica}$ and the structures determined by spectroscopic methods, chemical transformations, and X-ray crystallographic analysis.     

N-halogeno-compounds. Part II [1]. N.M.R. data for polyfluorocyclohexadienylideneamines obtained via N- chlorination of polyfluoroarylamines

N.m.r. parameters for nine (I-IX) $\text{N}$-chloropolyfluorocyclohexa-2,5-dienylideneamines are reported and discussed; the magnitudes of the FF-coupling constants fall into the following ranges:

$\text{J}$₁₂ 0-2.8; $\text{J}$₁₃, $\text{J}$₃₅ 6.0-6.8; $\text{J}$₁₄ <1; $\text{J}$₁₅ 0-2.6; $\text{J}$₂₃, $\text{J}$₃₄ 25.5-27.2; $\text{J}$₂₄ 0-6.0; $\text{J}$₂₅ 0-1.2; $\text{J}$₄₅ 5.4-9.8 Hz (I) X = Y = Z = F; (II) X = OMe, Y = Z = F; (III) X - CF₃, Y = Z = F; (IV) X = Ph, Y = Z = F; (V) X = Cl, Y = Z = F; (VI) X = Br, Y = Z = F; (VII) X = Y = F, Z = Cl; (VIII) X = Y = F, Z = Br; (IX) X = Z = F, Y = H. The spectra of $\text{N}$-methyl-4-chloropentafluorocyclohexa-2,5-dienyldeneamine have also been analysed. All the imines examined are configurationally stable at the nitrogen atom.     

Base-induced intramolecular cyclisation of N-(o-azidobenzoyl)-arylamines. A new synthesis of 2-aryl-1,2-dihydro-3H-indazolin-3-ones

In strong base, e.g., sodium hydride in dimethylformamide, $\text{N}$-($\text{o}$-azidobenzoyl)arylamines cyclise in high yield to 2-aryl-1,2-dihydro-3$\text{H}$-indazolin-3-ones.     

Advanced sedex (sensitive detector of exothermic processes)

The instrument described is suitable for the investigation of the thermal behaviour of substances and reaction mixtures under production conformable conditions; this is made possible by the sophisticated design of the sample chamber: easy stirring of the samples, measuring under any gas atmosphere and while bubbling gas through the sample, choice of the sample container and visual observation during the measurement. The control device allows the choice of one of three operational modes: constant temperature, linear increase in temperature, and adiabatic control; this permits the application of the SEDEX apparatus for a variety of methods including dynamic scanning, isoperibolic measurements, and (quasi) adiabatic studies.     

Penicillin N-cyanosulphilmines; cyanamide/iodobenzene diacetate,a convenient cyanonitrene reagent for N-cyano sulphilmines,sulphoximines, phosphinimines and aziridines

Cyanamide with iodobenzene diacetate give cyanonitrene adducts of sulphides, sulphoxides, phosphines, and olefins. Penicillins give $\text{N}$-cyanosulphilimines, shown by intramolecular N-H...N hydrogen bonding or NMR ASIS to have β(S) stereochemistry.