Rh(III)-Catalyzed [3+2]/[4+2] Annulation of Acetophenone Oxime Ethers with 3-Acetoxy-1,4-enynes involving C-H Activation

We here report a rhodium(III)-catalyzed [3+2]/[4+2] annulation of acetophenone oxime ethers with 3-acetoxy-1,4-enynes involving activation of both the C-H bond and C-N -bond for producing trans-2,9b-dihydro-1H-indeno[1,2-b]pyridines with excellent chemo-, regio-...

Synthesis of a Number of Unsymmetrical Bridged Terphthaloyl Acetophenone Oxime Esters

A number of unsymmetrical bridged terphthaloyl acetophenone oxime esters has been synthesized throughout an esterification reaction between four different acetophenone oximes and the terphthaloyl chloride in a molar ratio of (2:1) under mild basic conditions. Spectroscopic techniques, such as IR, HNMR and mass spectrometer, were used to confirm the structures of the targeted oxime esters. The yields of the obtained oxime esters ranged from 80% to 95%.

Synthesis of Some Bridged Unsymmetrical Terphthaloyl Oxime Esters

Three unsymmetrical bridged terphthaloyl acetophenone oxime esters have been synthesized throughout an esterification process between three acetophenone oximes and the terphthaloyl chloride under mild basic conditions. Spectroscopic techniques, such as IR, HNMR and mass spectrometer, were used to confirm the structures of the desired oxime esters. The yields of the resulting oxime esters ranged from 50% to 73%.

Variability of Rhodium(III)-Catalyzed Reactions of Aromatic Oximes with Alkenes

Acetophenone oxime reacts with various alkenes in the presence of the rhodium catalyst [Cp*RhCl2]2 (2.5 mol%; Cp* = pentamethylcyclopentadienyl) and 1,1,1,3,3,3-hexafluoropropan-2-ol as an important cosolvent. Styrene, aliphatic terminal alkenes, and strained cyclic alkenes gave the corresponding substituted dihydroisoquinolines in yields of 50–99%. On the other hand, alkenes containing functional groups close to the double bond gave a variety of different products. The reactions of acetophenone oxime with styrene or dec-1-ene in the presence of the chiral catalyst [(C5H2 t Bu2CH2 t Bu)RhI2]2 provided the corresponding dihydroisoquinolines with improved regioselectivity but a low enantiomeric ratio (61:39 in both cases).

Functionalization of C–H bonds in acetophenone oximes with arylacetic acids and elemental sulfur

Annulation of acetophenone oxime acetates, arylacetic acids or esters, and elemental sulfur in absence of transition metals is reported.

Formation of Benzodiazepines and Pyrazinylquinoxalines from Aromatic and Heteroaromatic Ketones via Deoximation

The report stated that the treatment of o-phenylenediamine with acetone dicarboxylic acid, acetone and acetophenone afforded 2,4,4-trimethyl-3H-5-hydro-1,5-benzodiazepine. However, direct reactions of o-phenylenediamine with oximes (acetone oxime, acetophenone oxime, and benzophenone oxime) as ketone equivalents did not occur. In the course of present investigations, it is found that dichloroamine-T can be an efficient reagent for the conversion of oximes into the corresponding carbonyl compounds. As a part of a research program related to the synthetic study of pharmacologically interesting benzodiazepine compounds, herein the synthesis of 1H-1,5-benzodiazepine derivatives from heteroaromatic ketones and acetone equivalents obtained using dichloroamine-T. On the other hand, when diamine (1,2-phenylene diamine or 1,2-naphthalene diamine) with heterocyclic ketone (acetyl pyridine or acetyl pyrazines) in the presenece of conc. HCl and SiO2 was refluxed, quinoxaline derivatives as yellow crystalline solids were isolated in high yields

Elemental tellurium mediated synthesis of 2-(trifluoromethyl)oxazoles using trifluoroacetic anhydride as reagent

An elemental tellurium mediated synthesis of 2-(trifluoromethyl)oxazoles from the reaction of acetophenone oxime acetates with trifluoroacetic anhydride is described.