Deoxygenation of Epoxides with Hexamethyldigermane Catalyzed by Au Nanoparticles on TiO2 DOI

Anastasia Louka,

Manolis Stratakis

Asian Journal of Organic Chemistry, Год журнала: 2021, Номер 10(12), С. 3364 - 3369

Опубликована: Окт. 29, 2021

Abstract Mono‐ and disubstituted epoxides undergo quantitative deoxygenation into the corresponding alkenes by hexamethyldigermane (Me 3 GeGeMe ) in presence of 1 mol% supported Au nanoparticles on TiO 2 , with digermane being transformed digermoxane. Tri‐ tetrasubstituted react either poorly or remain intact, allowing thus selective intermolecular a monosubstituted epoxide highly substituted one. Stereoisotopic studies Hammett‐type kinetics indicate dipolar transition state process, whose degree polarity profile depends substituents. For alkyl‐substituted is almost stereospecific (retention configuration), while for aryl‐substituted ones, which character more profound, substantial loss stereospecificity observed.

Язык: Английский

Interrupted Dance of Five Heteroatoms: Reinventing Ozonolysis to Make Geminal Alkoxyhydroperoxides from C═N Bonds DOI
Ivan A. Yaremenko, Dmitri I. Fomenkov, Roman A. Budekhin

и другие.

The Journal of Organic Chemistry, Год журнала: 2024, Номер 89(8), С. 5699 - 5714

Опубликована: Апрель 2, 2024

Four heteroatoms dance in the cascade of four pericyclic reactions initiated by ozonolysis C═N bonds. Switching from imines to semicarbazones introduces fifth heteroatom that slows this dance, delays reaching thermodynamically favorable escape path, and allows efficient interception carbonyl oxides (Criegee intermediates, CIs) an external nucleophile. The new three-component reaction alcohols, ozone, oximes/semicarbazones greatly facilitates synthetic access monoperoxyacetals (alkoxyhydroperoxides).

Язык: Английский

Процитировано

4

Hydrosilylation or Dehydrogenative Silylation Pathways via the Au-Catalyzed Activation of Hydrosilanes DOI

Maria Ioanna Karapanou,

Marios Kidonakis,

Dimitra Malliotaki

и другие.

Journal of Organometallic Chemistry, Год журнала: 2025, Номер unknown, С. 123546 - 123546

Опубликована: Янв. 1, 2025

Язык: Английский

Процитировано

0

Osmium catalysis in the reductive amination using carbon monoxide as a reducing agent DOI
Mikhail M. Vinogradov, Oleg I. Afanasyev, Yulia V. Nelyubina

и другие.

Molecular Catalysis, Год журнала: 2020, Номер 498, С. 111260 - 111260

Опубликована: Окт. 30, 2020

Язык: Английский

Процитировано

10

The Higher Propensity of Pd-SiHEt2+ over Pd-SiMe2Et+ to Transfer Silylium to Silyl Ether Intermediates Explains Divergent Products in Ketone Hydrosilylation Catalysis DOI

Eric W. Roos,

Kevin Basemann, Michel R. Gagné

и другие.

Organometallics, Год журнала: 2024, Номер 43(11), С. 1256 - 1263

Опубликована: Май 31, 2024

The catalytic use of silylpalladium cations has been developed for the hydrosilylation ketones. Product outcome was heavily influenced by hydrosilane identity with tertiary silanes providing silyl ethers and secondary silanes, alkanes. Stoichiometric studies suggest a key differentiating feature is ability to transfer silylium from XantPhosPd-SiR3+ ether intermediates in case but not tertiary. Formation bimetallic Pd species during catalysis points behaving as source both electrophilic ions nucleophilic Pd(0).

Язык: Английский

Процитировано

1

Au Nanoparticle-Catalyzed Double Hydrosilylation of Nitriles by Diethylsilane DOI Creative Commons

Maria Ioanna Karapanou,

Dimitra Malliotaki,

Manolis Stratakis

и другие.

Organic & Biomolecular Chemistry, Год журнала: 2024, Номер 22(26), С. 5346 - 5352

Опубликована: Янв. 1, 2024

We present the first example of Au-catalyzed reduction nitriles into primary amines. In contrast to monohydrosilanes which are completely unreactive, diethylsilane (a dihydrosilane) is capable reducing aryl or alkyl amines under catalysis by Au nanoparticles supported on TiO

Язык: Английский

Процитировано

1

Substitution-Dependent Ring-Opening Hydrosilylation or Dehydrogenative Hydrosilylation of Cyclopropyl Aldehydes and Ketones Catalyzed by Au Nanoparticles DOI

Ioannis Zachilas,

Marios Kidonakis,

Maria Ioanna Karapanou

и другие.

The Journal of Organic Chemistry, Год журнала: 2022, Номер 87(23), С. 15914 - 15924

Опубликована: Ноя. 17, 2022

The reaction between hydrosilanes and aryl-substituted cyclopropyl aldehydes or ketones catalyzed by Au nanoparticles supported on TiO2 provides two distinct ring-opening motifs depending the substituents. 2-Aryl-substituted carbonyl compounds form linear enol ethers via formal silyl hydride addition carbon atom bearing aryl group. Under conditions, hydrosilylation adducts undergo hydrolytic deprotection to acyclic ketones. For 2,2-arylalkyl- 2,2-diaryl-substituted compounds, a dehydrogenative pathway is solely observed yielding chromatographically stable silyloxy-1,3-dienes. In presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), inhibited, indicative radical pathway. proposed intermediate α-cyclopropyl silyloxy radicals radical-clock benzyl radicals, which may either be captured hydrosilane H (for 2-aryl-substituted substrates) eliminate H2 silyloxy-1,3-dienes in case bulkier 2,2-disubstituted ones.

Язык: Английский

Процитировано

3

Transition Metal Promoted Synthesis of Isoindoline Derivatives DOI
Gianluigi Albano, Laura Antonella Aronica

Опубликована: Апрель 15, 2022

Isoindoline can be considered as the "hydrogenated sister" of isoindole which is widespread in nature heterocyclic core alkaloids and antibiotics. This chapter devoted to analysis methods involving use transition metal catalysts with particular regard activity specific organometallic species. Transition-metal-catalysed cyclisations three π-systems have been deeply investigated valuable synthetic tool for generation aromatic rings. Transition metal-promoted Diels-Alder reactions represent a very convenient methodology synthesis nonaromatic nitrogen heterocycles. Several metals successfully adopted intramolecular aza-Michael addition ortho-alkenyl benzyl amine derivatives. A relevant route isoindolines based on 5-exo-dig cyclization through C—C bond formation achieved by a-arylation.

Язык: Английский

Процитировано

1

Reduction of Carbonyl Compounds by Diethylsilane Catalyzed by Titania-Supported Gold Nanoparticles DOI
Yasuhiro Uozumi,

Ryoko Niimi

Synfacts, Год журнала: 2020, Номер 16(10), С. 1205 - 1205

Опубликована: Сен. 17, 2020

Key words gold catalysis - nanoparticles reduction diethylsilane carbonyl compounds catalyst support

Язык: Английский

Процитировано

0

Deoxygenation of Epoxides with Hexamethyldigermane Catalyzed by Au Nanoparticles on TiO2 DOI

Anastasia Louka,

Manolis Stratakis

Asian Journal of Organic Chemistry, Год журнала: 2021, Номер 10(12), С. 3364 - 3369

Опубликована: Окт. 29, 2021

Abstract Mono‐ and disubstituted epoxides undergo quantitative deoxygenation into the corresponding alkenes by hexamethyldigermane (Me 3 GeGeMe ) in presence of 1 mol% supported Au nanoparticles on TiO 2 , with digermane being transformed digermoxane. Tri‐ tetrasubstituted react either poorly or remain intact, allowing thus selective intermolecular a monosubstituted epoxide highly substituted one. Stereoisotopic studies Hammett‐type kinetics indicate dipolar transition state process, whose degree polarity profile depends substituents. For alkyl‐substituted is almost stereospecific (retention configuration), while for aryl‐substituted ones, which character more profound, substantial loss stereospecificity observed.

Язык: Английский

Процитировано

0