Novel synthesis of 3-phenyloxaziridines

Facile and efficient method for preparation of schiff bases catalyzed by P2O5/SiO2 under free solvent conditions

“…The crude product was purified by recrystallization in petroleum ether, and the pure Schiff base was obtained in 80% yield. The Schiff base products were identified and confirmed by the spectroscopic data and physical methods and were consistent with the previously reported data [21][22][23][24][25][26][27]. …”

“…As shown in Table 1, a series of Schiff bases were synthesized using P 2 O 5 /SiO 2 as a catalyst in solvent-free media. We were pleased to find that the reaction of different amines with benzaldehyde was obtained as the corresponding Schiff bases in good to excellent yields in a shorter time, using P 2 O 5 /SiO 2 than some of the previously reported methods [21][22][23][24][25][26][27]. In comparison, the reaction of benzaldehyde with 4-nitroaniline in the absence of a catalyst is given at entry 12 in Table 1.…”

Reaction of oxaziridine with heterocumulene. A ketene, isocyanates, and carbodiimide

“…The formation of a small amount of the isoquinolinedione 5b in the reaction of lb is perhaps caused by the recombination of the intermediate 23 In this case, a nucleophilic attack by an oxygen atom results exclusively in an acetal-type intermediate 30, which is expected to be formed from its isomeric nitrone and the ketene. This mechanism, however, is excluded by the reaction of -phenyl-N-tert-butylnitrone with the ketene under the same conditions, giving no rearranged amide but the /3-lactam 31.…”

An Environmentally Friendly Oxidation System for the Selective Oxygenation of Aldimines to Oxaziridines with Anhydrous TBHP and Alumina‐Supported MoO3 as a Recyclable Heterogeneous Catalyst

“…[2] Oxygenation of imines is an important synthetic transformation as oxaziridines are synthetically important building blocks that find wide application in asymmetric synthesis, [3][4][5] in the preparation of biologically active compounds [6,7] and extensively used as nitrogen [8,9] and oxygen [10,11] transfer reagents in various synthetically important reactions. A variety of oxidizing agents such as m-CPBA, [12][13][14][15][16] Ac 2 O/H 2 O 2 , [17] urea/H 2 O 2 , [18] H 2 O 2 /nitrile, [19,20] tert-amyl hydroperoxide [21] and molecular oxygen [22,23] in the presence of transition metals were used to accomplish this transformation. However, most of these methods are associated with drawbacks such as harsh reaction conditions, the use of aldehydes as a sacrificial agent, the formation of side products, poor yields and difficult work up procedures, which leaves room to develop an efficient and simple process for the oxygenation of imines to oxaziridines.…”