Reversing the Native Aerobic Oxidation Reactivity of Graphitic Carbon: Heterogeneous Metal-Free Alkene Hydrogenation

Abstract

Commercially available carbon blacks serve as effective metal-free catalysts for the selective hydrogenation of carbon–carbon multiple bonds under aerobic conditions using hydrazine as the terminal reductant. The reaction, which proceeds through a putative diimide intermediate, displays high tolerance to a variety of functional groups, including those sensitive to nucleophilic displacement by hydrazine, aerobic oxidation, or hydrazine-mediated reduction. Hydrazine chemisorbs strongly to the carbon surface, attenuating its native oxidative reactivity and allowing for selective hydrogenation. The catalytic sequence established here effectively umpolungs the reactivity of carbon, thereby enabling the use of this low-cost material in selective reduction catalysis.

Catalytic properties of nanocarbon materials in reaction of selective hydrogenation of acetylene

“…Каталітичну активність ВОГ у реакціях гідрування було показано на прикладі відновлення нітросполук до амінів за допомогою NaBH 4 , гідразингідрату та NaAlH 4 [6][7][8]. Також було виявлено, що ВОГ є каталітично активним у гідруванні органічних сполук молекулярним воднем у рідкій фазі за високого тиску [9,10].…”

A Metal-Free Carbon-Based Catalyst: An Overview and Directions for Future Research

“…For obtaining narrow pore size distribution (PSD) with a low proportion of micropores, mesoporous carbon as a catalyst was developed [176]. Murray et al [177] reported that the selective hydrogenation of olefins to alkanes was obtained using carbon blacks and hydrazine under aerobic conditions (Scheme 19). This reaction continued with a variety of sensitive functional groups tolerance via a diimide intermediate.…”

“…The reaction mechanism of ADD-mediated catalytic processes is shown in Scheme 20. [177]. Reprinted with permission from [177].…”

“…Monarch 1300 carbon-catalyzed hydrogenation reaction. From Murry et al[177]. Reprinted with permission from[177].…”

Visible-Light-Induced Hydrogenation of C═C Bonds by Hydrazine over Ultrathin Layered Double Hydroxide Nanosheets

“…Compared with the traditional thermal catalysis, photocatalysis attracts broad attention due to its potential to capture solar energy and drive thermodynamically unfavorable reactions under mild conditions. − During the photocatalytic process, the photoinduced charge carriers (electron–hole pairs) have shown potential application in driving abundant reduction reactions, such as water splitting into hydrogen, CO 2 reduction, and some organic synthesis, and has gained significant interest in recent years. , In recent years, ultrathin two-dimensional layered photocatalytic materials have been used as efficient photocatalysts in photocatalytic water splitting and CO 2 \N 2 reduction. − Among the layered materials, layered double hydroxides (LDHs) with the general formula of [M 1 – x 2+ M x 3+ ] q + (A n – ) q / n · γH 2 O (where M 2+ = Mg 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ ; M 3+ = Al 3+ , Cr 3+ ; and A n – are charge balancing anions located between layers) gain great attention from the photocatalysis area because of their easily controllable metal cation composition and thicknesses, adjustability of defects, and tunable band gap, providing a robust platform for the efficient photocatalytic performance. , According to the pieces of literature, a large population of superoxide radicals can be produced on LDH surfaces under the visible light, given the potential application in the oxidation of hydrazine, yielding the formation of diimine species that can act as a potential hydrogenation agent to give the reduction of olefins under mild conditions. ,− From the above considerations, we believe that the photoactive LDHs can give hydrogenation of olefins by using N 2 H 4 as a reducing agent under mild conditions.…”