Recent Advances in N-O Bond Cleavage of Oximes and Hydroxylamines to Construct N-Heterocycle

Abstract

Oximes and hydroxylamines are a very important class of skeletons that not only widely exist in natural products and drug molecules, but also a class of synthon, which have been widely used in industrial production. Due to weak N-O σ bonds of oximes and hydroxylamines, they can be easily transformed into other functional groups by N-O bond cleavage. Therefore, the synthesis of N-heterocycle by using oximes and hydroxylamines as nitrogen sources has attracted wide attention. Recent advances for the synthesis of N-heterocycle through transition-metal-catalyzed and radical-mediated cyclization classified by the type of nitrogen sources and rings are summarized. In this paper, the recent advances in the N-O bond cleavage of oximes and hydroxylamines are reviewed. We hope that this review provides a new perspective on this field, and also provides a reference to develop environmentally friendly and sustainable methods.

The diacetyliminoxyl radical in oxidative functionalization of alkenes

“…The synthesized C–O coupling products could be catalytically converted into hydroxylamine derivatives 71–73 or further employed as substrates for iminyl radical chemistry. 74–76…”

“…The synthesized C-O coupling products could be catalytically converted into hydroxylamine derivatives [71][72][73] or further employed as substrates for iminyl radical chemistry. [74][75][76] Next, we turned our attention to aliphatic alkenes (Table 3). Allylic substitution products 5a and 5b were obtained from cyclopentene 4a and cyclohexene 4b in low yields (18-27%).…”

Recent Progress in Hard Carbon Anodes for Sodium‐Ion Batteries

“…The current precursors include resin-based (e.g., phenolic resins, epoxy resins), [33,34] polymer-based (e.g., polyacrylonitrile, polyvinylpyrrolidone), [35][36][37][38] biomass-based (e.g., cellulose, lignin), [24,39,40] carbohydrate-based (e.g., sucrose, dextrose), [41] and synthetic wastes, [42,43] and other feedstocks, Moreover biomass-based materials can be prepared by different plant precursors. [44][45][46][47][48] Yu et al [49] used sugarcane bagasse as feedstock, which could provide a reversible capacity of 315.3 mAh g À1 by pyrolysis treatment and microwave activation. Song et al [46] synthesized hard carbon by using corn cob as a feedstock at pyrolysis temperatures ranging from 1000 to 1600 °C, and as the pyrolysis temperature increases, the number of graphite microcrystalline layers increases, generating a pore structure with wider distribution and larger size, improving the specific capacity, initial coulombic efficiency (ICE), and multiplicity performance.…”

“…[44][45][46][47][48] Yu et al [49] used sugarcane bagasse as feedstock, which could provide a reversible capacity of 315.3 mAh g À1 by pyrolysis treatment and microwave activation. Song et al [46] synthesized hard carbon by using corn cob as a feedstock at pyrolysis temperatures ranging from 1000 to 1600 °C, and as the pyrolysis temperature increases, the number of graphite microcrystalline layers increases, generating a pore structure with wider distribution and larger size, improving the specific capacity, initial coulombic efficiency (ICE), and multiplicity performance. The plant biomass contains some other elements in addition to carbon elements, such as N, Si, and P, which modulate and improve the structure of the synthesized hard carbon to optimize the sodium storage properties of hard carbon.…”

Ferrocene catalyzed carbohydroxylation of alkenes using H2O and cycloketone oxime esters

“…16 Moreover, considering the importance of cyanoalkyl functional molecules, 17 there has been substantial utilization of cycloketone oxime esters as valuable precursors for the synthesis of functionalized cyanoalkyl compounds. 18 In this study, we present, for the first time, a novel application of Cp 2 Fe as a catalyst for the direct carbohydroxylation of aryl alkenes, employing cycloketone oxime esters and water (Scheme 1).…”