Takafumi Yatabe

Flavones are a class of natural products with diverse biological activities and have frequently been synthesized by step-by-step procedures using stoichiometric amounts of reagents. Herein, a catalytic one-pot procedure for the synthesis of flavone and its derivatives is developed. In the presence of gold nanoparticles supported on a Mg-Al layered double hydroxide (Au/LDH), various kinds of flavones can be synthesized starting from 2'-hydroxyacetophenones and benzaldehydes (or benzyl alcohols).

Flavonoids, which are ubiquitous plant secondary metabolites obtained from chalcones, mostly possess 6-membered C-rings derived from 6-endo-trig cyclization of chalcones. However, aurones, which are a class of flavonoids that rarely occur naturally, possess unusual 5-membered C-rings biosynthesized from chalcones by mainly performing B-ring oxidation. Therefore, the chemical catalytic transformation from simple chalcones into aurones is attractive, because it overcomes the drawback of known limi

By utilizing hydrazine (N₂H₄) as the nitrogen source in the presence of a hydroxyapatite-supported Pd nanoparticle catalyst (Pd/HAP), various primary anilines can be selectively synthesized from cyclohexanones via acceptorless dehydrogenative aromatization. The strong nucleophilicity of N₂H₄ and the stability of the hydrazone intermediates can effectively suppress the formation of the undesired secondary aniline byproducts.

Although catalytic dehydrogenative aromatization from cyclohexanones and NH₃ is an attractive synthetic method for primary anilines, using a hydrogen acceptor was indispensable to achieve satisfactory levels of selectivity in liquid-phase organic synthetic systems without photoirradiation. In this study, we developed a highly selective synthesis of primary anilines from cyclohexanones and NH₃ via efficient acceptorless dehydrogenative aromatization heterogeneously catalyzed

Although hydroacylation is a very useful reaction for producing ketones from aldehydes with 100% atom efficiency, classical Rh-catalyzed hydroacylation presents several problems, including the need for transition metal catalysts, unwanted decarbonylation of aldehydes, and difficulty in regioselectivity control. However, formal hydroacylation utilizing the nucleophilicity of terminal alkynes can avoid these problems. In this work, we have achieved transition-metal-free formal hydroacylation of te

We focused on identifying a catalytic active site structure at the atomic level and elucidating the mechanism at the elementary reaction level of liquid-phase organic reactions with a heterogeneous catalyst. In this study, we experimentally and computationally investigated efficient C-H bond activation for the selective aerobic α,β-dehydrogenation of saturated ketones by using a Pd-Au bimetallic nanoparticle catalyst supported on CeO₂ (Pd/Au/CeO₂) as a case study. Detailed

Using Cu/ N -oxyl catalysts, a highly efficient aerobic oxidative esterification reaction of ethylene glycol to various oxalic acid diesters in the presence of other aliphatic primary alcohols was realized.

Abstract Flavones are a class of natural products with diverse biological activities and have frequently been synthesized by step‐by‐step procedures using stoichiometric amounts of reagents. Herein, a catalytic one‐pot procedure for the synthesis of flavone and its derivatives is developed. In the presence of gold nanoparticles supported on a Mg‐Al layered double hydroxide (Au/LDH), various kinds of flavones can be synthesized starting from 2′‐hydroxyacetophenones and benzaldehydes (or benzyl al

Regioselective transformations of tertiary amines, which are ubiquitously present in natural products and drugs, are important for the development of novel medicines. In particular, the oxidative α-C-H functionalisation of tertiary amines with nucleophiles via iminium cations is a promising approach because, theoretically, there is almost no limit to the type of amine and functionalisation. However, most of the reports on oxidative α-C-H functionalisations are limited to α-methyl-selective or no

This study rationally designed a heterogeneously catalyzed system (i.e., using Ni-Pd alloy nanoparticles supported on hydroxyapatite (Ni-Pd/HAP) under an H₂ atmosphere) achieving an efficient base-free formal C-S bond metathesis of various thiols via suppression of the Ni catalysis deactivation.

<i>m</i>-Disubstituted arenes are important in various fields but difficult to be directly synthesized by classical methods in the case of two electron-donating substituents due to the <i>o</i>,<i>p</i>-orientation. Dehydrogenative aromatization from nonaromatic cyclohexenone motifs and nucleophiles via 1,2- and 1,4-addition to produce <i>m</i>-disubstituted arenes is promising as the novel process overcoming the intrinsic problems derived from using aromatic compounds as the substrates; however

Here, an undirected acceptorless dehydrogenative silylation of benzylic C(sp 3 )–H bonds was developed using a CeO 2 -supported highly dispersed Ni(0) nanocatalyst.

Azobenzenes have been ubiquitously utilized and synthesized in well-established methods represented as azo coupling for a long time; however, all the available azobenzene synthesis strategies use aromatic compounds as substrates, which inherently limit the regioselectivity of substituents because of ortho/meta/para-orientation and frequently require multistep procedures. Dehydrogenative aromatization from cyclohexanones, which can be regioselectively functionalized using classical methods withou