홍석창 교수

A novel enantioselective synthetic method for the construction of a quaternary carbon center from malonates via phase-transfer catalytic (PTC) alkylation has been developed. The asymmetric α-alkylation of diphenylmethyl tert-butyl α-alkylmalonates with alkylating agents under phase-transfer catalysis conditions (aq 50% KOH, toluene, 0 °C) in the presence of (S,S)-3,4,5-trifluorophenyl-NAS bromide (8) as PTC catalyst afforded the corresponding α,α-dialkylmalonates in high chemical (up to 99%) and

The iron-catalyzed hydrogen transfer strategy has been applied to the redox condensation of <i>o</i>-hydroxynitrobenzene with alcohol, leading to the formation of benzoxazole derivatives. A wide range of 2-substituted benzoxazoles were synthesized in good to excellent yields without the addition of an external redox agent. A series of control experiments provided a plausible mechanism. Furthermore, the reaction system was successfully extended to the synthesis of benzothiazoles and benzimidazole

Herein, we describe the direct synthesis of quinazolinones via cross-dehydrogenative coupling between methyl arenes and anthranilamides. The C-H functionalization of the benzylic sp3 carbon is achieved by di-t-butyl peroxide under air, and the subsequent amination-aerobic oxidation process completes the annulation process. Iron catalyzed the whole reaction process and various kinds of functional groups were tolerated under the reaction conditions, providing 31 examples of 2-aryl quinazolinones u

Herein, we describe novel iron-catalyzed transfer hydrogenation between alcohols and 1-(2-nitrophenyl)pyrroles for the synthesis of pyrrolo[1,2-α]quinoxalines. The tricarbonyl (η⁴-cyclopentadienone) iron complex catalyzed the oxidation of alcohols and the reduction of nitroarenes, and the corresponding aldehydes and aniline were generated <i>in situ</i>. The resulting Pictet-Spengler-type annulation/oxidation completed the quinoxaline structure formation. The protocol tolerated variou

Benzimidazoles are important <i>N</i>-heteroaromatic compounds with various biological activities and pharmacological applications. Herein, we present the first iron-catalyzed selective synthesis of 1,2-disubstituted benzimidazoles <i>via</i> acceptorless dehydrogenative coupling of primary alcohols with aromatic diamines. The tricarbonyl (η⁴-cyclopentadienone) iron complex catalyzed dehydrogenative cyclization, releasing water and hydrogen gas as by-products. The earth abundance and

Metastatic triple-negative breast cancer (mTNBC) is a fatal type of breast cancer (BC), and signal transducer and activator of transcription 3 (STAT3) has emerged as an effective target for mTNBC. In the present study, compound <b>MC0704</b> was found to be a novel synthetic STAT3 pathway inhibitor, and its potential antitumor activity was demonstrated using <i>in vitro</i> and <i>in vivo</i> models in docetaxel-resistant TNBC cells. Based on marinacarboline (MC), a series β-carboline derivative

Herein, we describe the direct synthesis of pyrrolo[1,2-α]quinoxaline <i>via</i> oxidative coupling between methyl arene and 1-(2-aminophenyl) pyrroles. Oxidation of the benzylic carbon of the methyl arene was achieved by di-<i>t</i>-butyl peroxide in the presence of an iron catalyst, followed by conversion to an activated aldehyde <i>in situ</i>. Oxygen played a crucial role in the oxidation process to accelerate benzaldehyde formation. Subsequent Pictet-Spengler-type annulation completed the q

α-Alkyl and α-olefin nitriles are very important for organic synthesis and medicinal chemistry. However, different types of catalysts are employed to achieve either α-alkylation of nitriles by borrowing hydrogen or α-olefination by dehydrogenative coupling methods. Designing and developing high-performance earth-abundant catalysts that can procure different products from the same starting materials remain a great challenge. Herein, we report an iron(0) catalyst system that achieves chemoselectiv

Herein, we present the iron-catalyzed oxidative cyclization of alcohol/methyl arene with 2-amino styrene to synthesize polysubstituted quinoline. Low-oxidation level substrates such as alcohols and methyl arenes are converted to aldehydes in the presence of an iron catalyst and di-<i>t</i>-butyl peroxide. Then, the quinoline scaffold is synthesized through imine condensation/radical cyclization/oxidative aromatization. Our protocol showed a broad substrate scope, and various functionalization an

Herein, we describe the iron(III)-catalyzed oxidative coupling of alcohol/methyl arene with 2-amino phenyl ketone to synthesize 4-quinolone. Alcohols and methyl arenes are oxidized to the aldehyde in the presence of an iron catalyst and di-<i>tert</i>-butyl peroxide, followed by a tandem process, condensation with amine/Mannich-type cyclization/oxidation, to complete the 4-quinolone ring. This method tolerates various kinds of functional groups and provides a direct approach to the synthesis of

Here, we report iron-catalyzed one-pot synthesis of quinoxalines <i>via</i> transfer hydrogenative condensation of 2-nitroanilines with vicinal diols. The tricarbonyl (η4-cyclopentadienone) iron complex, which is well known as the Knölker complex, catalyzed the oxidation of alcohols and the reduction of nitroarenes, and the corresponding carbonyl and 1,2-diaminobenzene intermediates were generated <i>in situ</i>. Trimethylamine N-oxide was used to activate the iron complex. Various unsymmetrical

Abstract Herein, we report the divergent synthesis of quinolines and quinolones via a transfer hydrogenative condensation of ortho ‐nitrobenzyl alcohols in one step. The reaction proceeded using the cyclopentadienone iron complex without any additional redox reagents. After transfer hydrogenation between ortho ‐nitrobenzyl alcohols and secondary alcohols, the subsequent Friedländer annulation affords polysubstituted quinoline products in 22–90% (39 examples). The developed method was also applie

The site‐selective modifications of quinazolinones constitute a pivotal topic in drug discovery and material science. Herein, we describe the rhodium(III)‐catalyzed C–H amidation of 2‐aryl quinazolin‐4(3 H )‐ones with a range of nitrene surrogates including dioxazolones, organic azides, and N ‐methoxyamides. Complete site‐selectivity and functional group tolerance are observed. Notably, the large‐scale reaction and late‐stage functionalization highlight the synthetic potential of the developed p

Gaylussacin (<b>1</b>), a stilbene glucoside, has been isolated from <i>Pentarhizidium orientale</i> and is used in Korean folk medicine. Although it was first isolated in 1972, the synthesis of gaylussacin has never been reported. Herein, we report the first total synthesis of gaylussacin in six steps with an overall yield of 23.8%, as well as the synthesis of its derivatives. Structurally, gaylussacin contains a carboxylic acid and a glycoside along with a free phenol on the same benzene ring,

A new enantioselective synthetic method for α-halo-α-alkylmalonates is reported. α-Alkylation of diphenylmethyl tert-butyl α-halomalonates under phase-transfer catalytic conditions (solid KOH, toluene, -40 °C) in the presence of (S,S)-3,4,5-trifluorophenyl-NAS bromide (5 mol%) afforded diphenylmethyl tert-butyl α-halo-α-alkylmalonates in very high chemical yields (up to 99%) and optical yields (up to 93% ee).