14181-72-7

An unprecedented (3+1) cyclization of α-nitrosostyrenes, generated in situ from α-bromooximes, and N-tosyloxycarbamates was developed, which enables the synthesis of a range of structurally unique and hitherto unexplored 2,3-dihydrodiazete N-oxides in mod

A copper-catalyzed annulation of oxime acetates and α-amino acid ester derivatives for the easy preparation of 4-pyrrolin-2-ones bearing a 3-amino group has been developed. This process features the oxidation of amines with oxime esters as the internal oxidant to produce the active 1,3-dinucleophilic and 1,2-dielectrophilic species concurrently. The subsequent nucleophilic cyclization realizes the efficient construction of 4-pyrrolin-2-one derivatives.

2-Isoxazolines were synthesized efficiently from a formal [4+1] cycloaddition of nitrosoalkenes and sulfur ylides, which were generated in situ from α-haloketone oximes and dimethyl sulfonium salts. This approach provides a new method to synthesize a rang

The invention relates to novel laser markable compositions comprising developing agent precursors according to formula (I).

We present here the synthesis of novel (Z)-2-organylselanyl ketoximes by nucleophilic substitution reaction of E/Z mixtures of 2-bromo ketoximes with nucleophilic species of selenium, which were generated in situ by simple cleavage of diorganyl diselenides with NaBH4using ethanol/THF as solvent. The new 2-organylselanyl ketoximes were synthesized in moderate to good yields and with selectivity for the (Z)-configuration. The synthesized (Z)-2-arylselanylacetophenone oximes were submitted to the Beckmann rearrangement, furnishing the corresponding N-aryl-2-(selanyl)acetamides. (Z)-1-Phenyl-2-(phenylselanyl) ketoxime has antifungal activity against Sphaceloma ampelinum and a good level of antioxidant activity in vitro in DPPH, ABTS, FRAP and lipid peroxidation assays.

Nitrimines are employed as powerful reagents for metal-free formal C(sp2)-C(sp2) cross-coupling reactions. The new chemical process is tolerant of a wide array of nitrimine and heterocyclic coupling partners giving rise to the corresponding di- or trisubstituted alkenes, typically in high yield and with high stereoselectivity. This method is ideal for the metal-free construction of heterocycle-containing drug targets, such as phenprocoumon.

The synthesis of polyfunctionalized pyrroles by reaction of a ketoxime with dimethyl acetylenedicarboxylate using europium(III) triflate as the catalyst is described. Copyright

1,3-Dipolar cycloaddition of nitrones with arynes generated in situ from benzobisoxadisilole or 2,3-naphthoxadisilole afforded the oxadisilole fused benzo[d]isoxazoline or the naphtho[2,3-d]isoxazoline derivatives at room temperature in good yields.

Reaction of α-bromoketone oximes with diazo compounds in the presence of a metal catalyst and base led to the unprecedented formation of two types of rings: Δ2-isoxazolines and 1-nitrosopyrazolines.

A new type of stable C60-fused dihydrooxazine derivatives was successfully prepared by the hetero-Diels-Alder reaction of C60 with nitrosoalkene generated in situ by extrusion of HBr from the corresponding α-bromooxime.

The syntheses of some novel carboacyclic nucleosides, 17a-17o, containing oxiconazole-like scaffolds, are described (Schemes 1-3). In this series of carboacyclic nucleosides, pyrimidine as well as purine and other imidazole derivatives were employed as an imidazole successor in oxiconazole. These compounds could be prepared in good yields by using two different strategies (Schemes 1 and 2). Due to Scheme 1, the N-coupling of nucleobases with 2-bromoacetophenones was attained for 18a-18e, and their subsequent oximation affording 19a-19e and finally O-alkylation with diverse alkylating sources resulted in the products 17a-17g, 17n, and 17o. In Scheme 2, use of 2-bromoacetophenone oximes 20, followed by N-coupling of nucleobases, provided 19f-19j whose final O-alkylation produced 17h-17m (Scheme 2). For the rational interpretation of the dominant formation of (E)-oxime ethers rather than (Z)-oxime isomers, PM3 semiempirical quantum-mechanic calculations were discussed and the calculations indicated a lower heat of formation for (E)-isomers.

Four kinds of vanadyl-hydroxythiazolethione complexes with VO(S 2O2) coordination mode were newly synthesized, and demonstrated for the first time that the insulinomimetic activity apparently correlates to the Hammett's substituent c

Carbon radicals derived from the esters of several types of thiohydroxamic acids have been trapped in a number of different ways.Particular attention has been paid to carbon-carbon bond formation by addition to suitably activated ethylenic linkages.Carboxylic acids can be conveniently converted into homo- and bishomo-acids by free radical chemistry based on thiohydroxamic esters.In a coda the tautomerism of the thiohydroxamic acids have been examined by physical methods.It is confirmed that the esters used are derivatives of the thione tautomer.