Carbon–carbon/carbon–heteroatom bond formation via oxidative transformations is a heavily explored topic at the frontier of chemistry. Potassium persulfate (K2S2O8) has emerged as a cost-effective, suitable inorganic oxidant for a wide array of oxidative transformations, ranging from laboratory experiments to industrial processes. The current review provides a comprehensive coverage of oxidative transformations aided with K2S2O8 in the presence or absence of a transition-metal catalyst, critical assessment of the results, and underlying mechanisms. Organic chemists may find this review to be a useful guide for the expedient synthesis of new chemical entities, to formulate mechanistic manifolds involving the sulfate radical anion, or to design novel oxidative transformations. A detailed understanding of the unsolved mechanisms could further enrich the field.

A new [3 + 3]-and [3 + 4]-annulation strategy involving azaoxyallyl cation and [1,m]-amphoteric compounds (m = 3,4) is presented. This concise method enables easy assembly of functionalized saturated N-heterocycles, comprised of six-and seven-membered rings and is of high significance in the context of drug discovery approaches. This reaction also represents a new trapping modality of the azaoxyallyl cation with amphoteric agents of different chain lengths that consist of a heteroatom nucleophilic site and a πelectrophilic site.

The Lewis acid catalyzed ring opening reaction of Donor−Acceptor (D−A) cyclopropanes with alkyl hydroperoxides is reported to furnish various peroxycarbonyls and 1,3-haloperoxygenated compounds in good to excellent yields. This method adds another instance to scarcely reported noncyclilizing 1,3-bisfunctionalization of D−A cyclopropanes with two different functional groups and relies on the dual role of peroxide as nucleophile and oxidant through an orchestrated reaction sequence. The products obtained, including α-heterosubstituted peroxy compounds, are amenable to useful synthetic elaboration.

Herein, a transition metal-free approach for the access to 3,3’-disubstituted peroxyoxindole is disclosed which harnesses transient azaoxyallyl cation. The strategy is also applicable to the synthesis of structurally diverse α-peroxycarboxylic...

Herein, development and detailed investigation of a S N '-type intramolecular aromatic substitution reaction involving α-arylazaoxyallyl cation intermediate, is disclosed. The study showcased that while α-aryl-α-chlorohydroxamate could be activated by a combination of base and 1,1,1,3,3,3hexafluoro-2-propanol (HFIP) into the corresponding azaoxyallyl cations, it could further emerge into a π-extended species involving the adjacent α-aryl moiety, and this transition is contingent on electronic effects of the aromatic ring as well as on α-substituents. An effective activation of the α-aromatic ring could pave the path for intramolecular Ar(Csp 2 )-N bond formation towards oxindoles. Control experiments and DFT calculations suggested that a non-pericyclic nucleophilic amination pathway is most likely operative and precluded the possibility of concerted or electrophilic amination mechanism. HFIP as the reaction solvent plays pivotal roles in the transformation.

thiourea derivativesthiourea derivatives (benzene compounds) Q 0650 -151Synthesis, Antineoplastic and Anthelmintic Activities of N-Alkyloxycarbonyl-N'-(4-benzyloxy-2-nitrophenyl)thioureas as Prodrugs of (6-Benzyloxy-1H-benzimidazol-2-yl)carbamic Acid Ester.-Biological activities of the compounds (VI) and (VII) are evaluated against Ehrlich ascites carcinoma, ascaris and hymenolepsis infected animals. The methyl carbamates (VIa) and (VIIa) cause 90 to 100% elimination of ascaris and hymenolepsis species while the ethyl carbamates (VIb) and (VIIb) show poor activity. Fermentation of (VIa) with E. coli results in the formation of the cyclic product (VIIa). Compound (VIa) cannot be considered as a prodrug of (VIIa) as expected, because the former is not inert and is rather more active than the latter. -(BERA, T.; BELSARE, D. P.; Indian J.

Herein, [3+2] dearomative indole cycloaddition reaction with oxindole embedded azaoxyallyl cation at C3 is developed. Use of this new class of azaoxyallyl cation species in the reaction enables the access to more elaborate hexahydropyrrolo[2,3-b]indole moieties that contain a spiro-oxindole ring. The transformation highlights good substrate scope and good regio- and stereoselectivity for cycloaddition step. Several observations suggested that this class of azaoxyallyl cation can display different reactivity pattern from the commonly employed azaoxyallyl cation systems in the relevant literature.

No abstract