Chiral NHC Ligands for Enantioselective Gold(I) Catalysis Under Aerobic Conditions: the Importance of Conformational Flexibility and Steric Hindrance of NHC Ligand on Reactivity DOI
Michał Michalak, Paweł J. Czerwiński, Katarzyna Śniady‐Maciążek

и другие.

Chemistry - A European Journal, Год журнала: 2023, Номер 30(13)

Опубликована: Дек. 21, 2023

Gold(I) catalysis has been recognized as a valuable tool for the unique transformation of multiple carbon-carbon bonds. Enantioselective π-catalysis based on gold(I) complexes is, however, still underdeveloped due to lack privileged ligands. Herein, we present an accessible method new family stable yet catalytically active chiral NHC-Au(I)-Cl complexes. The key preserving simultaneous fine balance between reactivity and stability in this newly developed appears be sterically hindered, but conformationally flexible NHC These could easily accessed multigram scale by merging hindered anilines with commercially available amino alcohols amines via four-steps synthetic sequence without need chromatographic purification. Further investigations catalytic activity NHC-Au-Cl identified OH functionality incorporated into core crucial level enantioselectivity well TsO- anion responsible activation NHC-Au(I)-Cl. Finally, NMR studies X-ray revealed first time that widely accepted ion metathesis (NHC-Au-Cl NHC-Au-OSO

Язык: Английский

DABCO-Catalyzed Synthesis of Thiazolidine-2-thiones: System Development and Mechanistic Insights DOI Creative Commons
Savvas G. Chalkidis, Sungil Hong,

Anthi-Markella Tsiadi

и другие.

The Journal of Organic Chemistry, Год журнала: 2025, Номер unknown

Опубликована: Март 19, 2025

A base-catalyzed protocol is reported for the construction of 1,3-thiazolidine-2-thione scaffolds bearing quaternary carbon centers from disulfide and α-tertiary propargylamines. The reaction proceeds using low catalyst loading, under ambient temperatures, in absence solvent. Various propargylamines have been employed, affording a series previously unreported thiazolidine-2-thione compounds avoiding purification via column chromatography certain cases. We also describe one-pot strategy synthesis same products through KA2 coupling–CS2 incorporation approach. mechanism substituent-dependent catalytic behavior were studied combination detailed experimental computational studies.

Язык: Английский

Процитировано

0
Hexafluoroisopropanol Solvent Effects on Enantioselectivity of Dirhodium Tetracarboxylate-Catalyzed Cyclopropanation DOI Creative Commons
Turki M. Alturaifi,

Kristin Shimabukuro,

Jack C. Sharland

и другие.

Journal of the American Chemical Society, Год журнала: 2025, Номер unknown

Опубликована: Апрель 16, 2025

In recent years, additives that modulate both reactivity and selectivity in rhodium-catalyzed reactions of aryldiazoacetates have become increasingly prominent. 1,1,1,3,3,3-Hexafluoroisopropanol (HFIP) has been shown to a profound effect on rhodium carbene selectivity, especially enabling cyclopropanation the presence various nucleophilic poisons. HFIP also variable influence enantioselectivity catalyzed by chiral dirhodium tetracarboxylates, this study examines fundamental properties carbene/HFIP system through experimentation, density functional theory (DFT), molecular dynamics (MD) simulations. These studies revealed C4-symmetric bowl-shaped catalysts, which previously considered be relatively rigid, experience far greater flexibility hydrogen bonding media, resulting distortion catalysts. explain why even though majority catalysts drop HFIP, some such as Rh2(TCPTAD)4, lead switch enantioselectivity, whereas others, Rh2(NTTL)4, considerably enhanced enantioselectivity.

Язык: Английский

Процитировано

0
Chiral Auxiliary Approach for Gold(I)‐Catalyzed Cyclizations DOI Creative Commons
Andrea Cataffo,

Miguel Peña‐López,

Riccardo Pedrazzani

и другие.

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(49)

Опубликована: Окт. 24, 2023

Two different classes of stereoselective cyclizations have been developed using a chiral auxiliary approach with commercially available [JohnPhosAu(MeCN)SbF6 ] as catalyst. First, cascade cyclization 1,5-enynes was achieved the Oppolzer camphorsultam auxiliary. In this case, one-pot cyclization-hydrolysis sequence to directly afford enantioenriched spirocyclic ketones. Then, alkoxycyclization 1,6-enynes mediated by an Evans-type oxazolidinone. A reduction-hydrolysis selected remove give β-tetralones. DFT studies confirmed that steric clash between and alkene accounts for experimentally observed diastereoselective through Si face.

Язык: Английский

Процитировано

10
An In‐Situ‐Formed Copper‐Based Perfluorinated Catalytic System for the Aerobic Oxidation of Alcohols DOI Creative Commons

Maria Drymona,

Entzy Kaplanai, Georgios C. Vougioukalakis

и другие.

European Journal of Organic Chemistry, Год журнала: 2024, Номер 27(7)

Опубликована: Янв. 8, 2024

Abstract Herein, we report a new catalytic protocol for the aerobic oxidation of alcohols. The system is formed in situ , straightforward and user‐friendly manner, combining widely available copper source (Cu 2 O) with one imidazolium salt precursor bearing perfluorinated moieties. Our uses TEMPO, as additive, reaction takes place at interface biphasic solvent system, consisting anisole 1‐bromoperfluorooctane. as‐prepared carbonyl compounds remain organic solvent, while remains fluorous phase. In this isolation purification desired products are quite facile. low loadings more efficient primary alcohols, affording good to excellent yields. phase containing can be efficiently recovered reused least six times, without significant decrease its efficiency.

Язык: Английский

Процитировано

2
Synthesis of N-heterocyclic carbene (NHC)-Au/Ag/Cu benzotriazolyl complexes and their catalytic activity in propargylamide cycloisomerization and carbonyl hydrosilylation reactions DOI Creative Commons
Entzy Kaplanai, Nikolaos V. Tzouras, Nikolaos Tsoureas

и другие.

Dalton Transactions, Год журнала: 2024, Номер 53(26), С. 11001 - 11008

Опубликована: Янв. 1, 2024

Carbene-metal-amide (CMA) complexes of gold, silver, and copper have been studied extensively for their photochemical/photocatalytic properties as potential (pre-)catalysts in organic synthesis. Herein, the design, synthesis, characterization five bench-stable Au-, Ag-, Cu-NHC bearing benzotriazolyl anion an amide donor, are reported. All synthesized a facile straightforward manner, using mild conditions. The catalytic activity Ag Cu was propargylamide cycloisomerization carbonyl hydrosilylation reactions. Both CMA-catalyzed transformations proceed under conditions highly efficient range propargylamides compounds, respectively, affording desired corresponding products good to excellent yields.

Язык: Английский

Процитировано

2
Continuous Flow Synthesis of Group 11 Metal‐NHC Complexes [M(IPr)(OC(H)(CF3)2)] (with M=Cu, Ag and Au) DOI
Andreas Simoens, Gianluca Carì, Sylwia Ostrowska

и другие.

Asian Journal of Organic Chemistry, Год журнала: 2024, Номер 13(4)

Опубликована: Янв. 22, 2024

Abstract The weak base method in continuous flow is currently one of the most sustainable and attractive approaches towards synthesis transition metal N‐heterocyclic carbene (NHC) complexes. Herein we broaden scope this by using it to produce [M(IPr)(OC(H)(CF 3 ) 2 )] complexes, including copper, silver, gold. These compounds bear alkoxide ligand within coordination sphere catalysts, which can open up new ways benefit from unique properties offered HFIP (1,1,1,3,3,3‐hexafluoroisopropanol) catalysis, while minimizing needed amount.

Язык: Английский

Процитировано

1
Dioxygen Activation by Gold(I)‐Distorted Porphyrin Dinuclear Complexes DOI
Wataru Suzuki, Yoshiyuki Mizuhata, Norihiro Tokitoh

и другие.

Chemistry - A European Journal, Год журнала: 2024, Номер 30(48)

Опубликована: Июнь 18, 2024

Interactions between gold-based materials and dioxygen (O

Язык: Английский

Процитировано

1
Gold(III) Catalysis in Ionic Liquids: The Case Study of Coumarin Synthesis DOI Creative Commons

Francesco Ravera,

Marte Sofie Martinsen Holmsen, Paolo Sgarbossa

и другие.

Advanced Synthesis & Catalysis, Год журнала: 2024, Номер 367(1)

Опубликована: Сен. 11, 2024

Abstract Well‐defined (P,C)‐cyclometalated Au(III) complexes proved to be able catalyze the synthesis of coumarins by intramolecular hydroarylation a broad range aryl propiolates under mild and practical conditions (0.1–2 mol% catalyst, 25–40 °C, 1–24 hours). The use an ionic liquid as reaction solvent allowed drastically decrease amount Brönsted acid used unlock catalyst regeneration step. effect nature additive anion have been assessed. Preliminary results on extension this methodology cyclization propargyl ethers are also presented.

Язык: Английский

Процитировано

1
Pnictogen Bonding at the Core of a Carbene-Stiborane-Gold Complex: Impact on Structure and Reactivity DOI Creative Commons

Paula Castro Castro,

François P. Gabbaı̈

Organometallics, Год журнала: 2024, Номер 43(19), С. 2334 - 2341

Опубликована: Сен. 26, 2024

Our interest in the design of ambiphilic ligands and their coordination to gold has led us synthesize an indazol-3-ylidene chloride complex functionalized at 4-position indazole backbone by a stibine functionality. The antimony center this new cleanly reacts with

Язык: Английский

Процитировано

1
Enantioselective Synthesis of Chiral β2-Amino Phosphorus Derivatives via Nickel-Catalyzed Asymmetric Hydrogenation DOI

Hanlin Wei,

Yicong Luo, Jinhui Li

и другие.

Journal of the American Chemical Society, Год журнала: 2024, Номер unknown

Опубликована: Дек. 27, 2024

Compared with chiral β3-amino phosphorus compounds, which can be easily derived from natural optically pure α-amino acids, obtaining β2-amino derivatives remains a challenge. These derivatives, cannot amino possess unique biological activities or potential catalytic activities. Herein, highly enantioselective hydrogenation for the preparation of E-β-enamido compounds is reported by using green and low-cost earth-abundant metal nickel catalyst (13 examples 99% ee). In particular, this system provides same enantiomer product E- Z-alkene substrates, E/Z-substrate mixtures provide good results (up to 96% The products diversely derivatized, exhibit as novel β2-aminophosphine ligands. Density functional theory calculations reveal that weak attractive interactions between substrate are crucial achieving perfect enantioselectivities. addition, different coordination modes Z-substrates may result in formation product.

Язык: Английский

Процитировано

1