Nitroacetylene equivalents. Preparation and cycloadditions of 2-phenylsulphinyl-1-nitroalkenes
作者:Michael E. Jung、David D. Grove
DOI:10.1039/c39870000753
日期:——
β-Phenylsulphinyl-nitro-alkenes (7) are readily prepared from acyl imidazoles and react as nitroacetyleneequivalents in Diels–Alder reactions to give good yields of cycloadducts and their further products.
phenylation reactions of α-acylnitromethanes catalyzed by trifluoromethanesulfonic acid have been studied. α-Aroylnitromethanes afforded benzil monooximes in good yield. In the case of aliphatic α-acylnitromethane, a similar phenylation reaction proceeded, but the yield of the phenylated 1,2-dione monooxime was low. These phenylation reactions represent examples of the generation of carbocation electrophiles
gel-supported sodium hydrogen sulfate (NaHSO4/SiO2) or Amberlyst 15 as solid acid catalyst, and then the corresponding 3-acylisoxaszoles were obtained by reacting with alkynes via the 1,3-dipolar [3+2] cycloaddition. These heterogeneous catalysts are easily separable from the reaction mixture and reused. This synthetic method provides a facile, efficient, and reusable production of 3-acylisoxazoles.
Facile synthesis of 2-nitromethyl aromatic ketones by insertion of benzynes into the C-C bond of α-nitroketones
作者:Ji-Hong Hu、Hong-Jie Zheng
DOI:10.1080/00397911.2018.1563794
日期:2019.2.16
Abstract A facile method to synthesize 2-nitromethyl aromatic ketones was developed. In the method, benzyne was generated in situ for the insertion to α-Nitroketones in one pot to achieve 2-nitromethyl aromatic ketones under mild conditions. Aromatic and aliphatic α-nitroketones were applied in the reaction, and the results show that aliphatic α-nitroketones gave excellent yields (up to 96%), while
was developed for the synthesis of N -alkoxyacylimidoyl halide by the reaction of α-nitro ketone and alkyl halides in the presence of NaHSO 4 /SiO 2 . Nitrile oxides that are generated from α-nitro ketones by silica gel supported acid catalysts are the possible intermediate, which react with alkyl halides to form N -alkoxyacylimidoyl halides. Novel 17 N -alkoxyacylimidoyl halides were synthesized by