Potassium tert‐Butoxide‐Promoted Acceptorless Dehydrogenation of N‐Heterocycles

Abstract

Potassium tert-butoxide-promoted acceptorless dehydrogenation of N-heterocycles was efficiently realized for the generation of N-heteroarenes and hydrogen gas under transition-metal-free conditions. In the presence of KOtBu base, a variety of six-and five-membered N-heterocyclic compounds efficiently underwent acceptorless dehydrogenation to afford the corresponding N-heteroarenes and H 2 gas in o-xylene at 140°C. The present protocol provides a convenient route to aromatic nitrogen-containing compounds and H 2 gas.

Synthesis, Molecular Docking Analysis and in Vitro Biological Evaluation of Some New Heterocyclic Scaffolds-Based Indole Moiety as Possible Antimicrobial Agents

“…Based on the experimental results, K. tert .butoxide promoted acceptor dehydrogenation plus actions as a basic catalyst reported in literature ( Liu et al, 2019 ), the reaction mechanism is understood. Initially, 2,4-pentadiene derivative (11) is prepared via condensation of cinnamaldehyde and ethyl cyanoacetate under the effect of basic catalyst.…”

Direct synthesis of p-methyl benzaldehyde from acetaldehyde via an organic amine-catalyzed dehydrogenation mechanism

“…This reaction follows an organic amine-catalyzed dehydrogenation mechanism via diene iminium intermediates. This process is different to the dehydrogenation-aromatization of N-heterocycles, in which potassium salt catalyzes the cleavage of N-H and C-H, thus resulting into H 2 formation ( Liu et al., 2019 ). In addition, the overall reaction rate remains constant when 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO), a commonly used radical-trapping reagent ( Tang, et al., 2021 ), was added in the reaction system, indicating that the conversion of acetaldehyde to p -MBA does not undergo a free radical route (see Figure S10 ).…”

Building C(sp3) Molecular Complexity on 2,2′‐Bipyridine and 1,10‐Phenanthroline in Rhenium Tricarbonyl Complexes

“…Metal complexes of group 4 containing the 2,3,4‐trihydro‐1,10‐phenanthroline ligand are efficient precatalysts for olefin polymerization [37] . The main synthetic route to access these complexes involves two steps—first the synthesis of the free ligand can be achieved by metal‐catalyzed partial reduction of phen [6b–f] to yield 1,2,3,4‐tetrahydro‐1,10‐phenanthroline and is followed by treatment with a metal alkyl precursor. In contrast, the strategy reported here for Re complexes avoids the need to use transition‐metal catalysts to access the partially reduced ligand.…”