scholarly journals Synergistic Palladium-Phosphoric Acid Catalysis in (3 + 2) Cycloaddition Reactions between Vinylcyclopropanes and Imines

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 150 ◽  
Author(s):  
Vasco Corti ◽  
Enrico Marcantonio ◽  
Martina Mamone ◽  
Alessandro Giungi ◽  
Mariafrancesca Fochi ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Palladium Catalyst ◽  
Palladium Catalysts ◽  
Acid Catalysis ◽  
Cycloaddition Reaction ◽  
Cross Coupling ◽  
Cycloaddition Reactions ◽  
Synergistic Catalysis ◽  
Palladium Catalyzed ◽  
First Time

The palladium-catalyzed (3 + 2) cycloaddition reaction between vinylcyclopropanes (VCPs) bearing geminal EWG’s and imines represents a straightforward and flexible entry to polysubstituted pyrrolidine derivatives. In this paper, we demonstrate that using a synergistic catalysis approach, based on the combination of phosphoric acid and palladium catalysts, it is possible to engage for the first time N-aryl and N-benzyl imines in this cycloaddition reaction. A range of polysubstituted pyrrolidines is obtained with moderate to good yields and diastereoselectivities, using a simple palladium species (Pd(PPh3)4) and an archetypical phosphoric acid as catalyst combination. A two-step scheme which exploits the same palladium catalyst for two consecutive and mechanistically distinct reactions (the cycloaddition and a Suzuki–Miyaura cross-coupling) is also presented. This synergistic catalysis approach is well posited for the development of the enantioselective version of this reaction. A screening of common BINOL-derived chiral phosphoric acids as catalyst component identified a species giving the product with moderate, yet promising, enantioselectivity (64% ee).

Umpolung Coupling of Pyridine-2-carboxaldehydes and Propargylic Carbonates via N-Heterocyclic Carbene/Palladium Synergetic Catalysis

2021 ◽  
Author(s):  
Weiyang Bi ◽  
Yunhui Yang ◽  
Song Ye ◽  
Congyang Wang
Keyword(s):  
Palladium Catalyst ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Cooperative Catalysis ◽  
Cross Coupling Reaction ◽  
First Time

The umpolung cross-coupling reaction of pyridine-2-carboxaldehydes and propargylic carbonates has been developed for the first time through N-heterocyclic carbene/palladium cooperative catalysis with the judicious selections of the palladium catalyst, ligand...

scholarly journals Palladium-catalyzed oxidative cross-coupling for the synthesis of α-amino ketones

RSC Advances ◽  
2019 ◽  
Vol 9 (55) ◽  
pp. 32081-32084
Author(s):  
Xiao-Hong Wei ◽  
Zhen-Hua Li ◽  
Lian-Biao Zhao ◽  
Ping Zhang ◽  
Han-Cheng Zhou ◽  
...  
Keyword(s):  
Palladium Catalysts ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed

A novel oxidative cross-coupling reaction for the synthesis of α-aryl α-amino ketones in the presence of palladium catalysts using T+BF4− as an oxidant has been developed.

scholarly journals Ab initio study of mechanism of forming a Si-heterocyclic spiro-Sn-heterocyclic ring compound by cycloaddition reaction of Me2Si=Sn: and ethene

2019 ◽  
Vol 44 (2) ◽  
pp. 114-121
Author(s):  
Xiaojun Tan ◽  
Xiuhui Lu
Keyword(s):  
Singlet State ◽  
Cycloaddition Reaction ◽  
Chemical Species ◽  
Heterocyclic Ring ◽  
Basis Set ◽  
Cycloaddition Reactions ◽  
Unoccupied Orbital ◽  
Donor Acceptor ◽  
Moller Plesset ◽  
First Time

X2Si=Sn: (X = H, Me, F, Cl, Br, Ph, Ar, etc.) are a new chemical species. The cycloaddition reactions of X2Si=Sn: are a new field of stannylene chemistry. The mechanism of the cycloaddition reaction between singlet state Me2Si=Sn: and ethene has been investigated for the first time here using second-order Møller-Plesset perturbation theory together with the 6-311++G** basis set for C, H and Si atoms and the LanL2dz basis set for Sn atoms. From the potential energy profile, it could be predicted that the reaction has one dominant reaction channel. The reaction process presented is that the 5p unoccupied orbital of Sn in Me2Si=Sn: and the π orbital of ethene form a π → p donor–acceptor bond resulting in the formation of an intermediate. The instability of this intermediate makes it isomerize to a four-membered Si-heterocyclic ring stannylene. Because the 5p unoccupied orbital of the Sn atom in the four-membered Si-heterocyclic ring stannylene and the π orbital of ethene form a π → p donor–acceptor bond, the four-membered Si-heterocyclic ring stannylene further combines with ethene to form another intermediate. Because the Sn atom in this intermediate assumes sp3 hybridization after the transition state, the intermediate isomerizes to a Si-heterocyclic spiro-Sn-heterocyclic ring compound. This result indicates the modes of cycloaddition reactions between X2Si=Sn: and symmetric π-bonded compounds, i.e. this study opens up a new field for stannylene chemistry.

Palladium-catalyzed aerobic regio- and stereo-selective olefination reactions of phenols and acrylatesviadirect dehydrogenative C(sp2)–O cross-coupling

2018 ◽  
Vol 54 (35) ◽  
pp. 4437-4440 ◽  
Author(s):  
Yun-Bin Wu ◽  
Dan Xie ◽  
Zhong-Lin Zang ◽  
Cheng-He Zhou ◽  
Gui-Xin Cai
Keyword(s):  
Oxidative Dehydrogenation ◽  
Palladium Catalyst ◽  
Cross Coupling ◽  
Palladium Catalyzed ◽  
Olefination Reactions

An efficient olefination protocol for the oxidative dehydrogenation of phenols and acrylates has been achieved using a palladium catalyst and O2as the sole oxidant.

scholarly journals Palladium Catalyzed Alternating Cooligomerization of Ethylene and Carbon Monoxide to Unsaturated Ketones

1995 ◽  
Vol 50 (3) ◽  
pp. 430-438 ◽  
Author(s):  
Wilhelm Keim ◽  
Heiko Maas ◽  
Stefan Mecking
Keyword(s):  
Carbon Monoxide ◽  
Palladium Catalysts ◽  
Methylene Chloride ◽  
General Structure ◽  
Phosphine Ligands ◽  
Unsaturated Ketones ◽  
Palladium Catalyzed ◽  
First Time ◽  
Cationic Palladium

Cationic palladium catalysts have been used to cooligomerize ethylene and carbon monoxide. At high ethylene/CO ratios (m /m = 10:1) in methylene chloride as a solvent, unsaturated alternating cooligomers of the general structure R[C(O)CH2CH2]mH ( m ≥ 1 ; R ≡CH2=CH-, CH2=CHCH2CH2- and CH3CH = CHCH2-) were obtained for the first time. Single component catalyst precursors [(allyl)Pd(P^X )]+Y- (P^X = Ph2P(CH2)nC(= O )OR, Ph2P(CH2)2P(=O)Ph2, Ph2P(CH2)nPh2P(CH2)2S (=O )Ph, n = 1 - 3 , R = Me, Et; Y- = BF4-, SbF6- ) with bidentate P,O- and P,S-ligands as well as in situ catalysts with unfunctionalized phosphine ligands were used. With P"Bu3 as a ligand, selectivities for ethylvinylketone of 40% based on the CO converted were obtained. The hemilabile phosphino-ester and phosphinothiophene ligands behave like monodentate phosphines under catalytic conditions.

Fully π-conjugated, diyne-linked covalent organic frameworks formed via alkyne-alkyne cross-coupling reaction

2022 ◽  
Author(s):  
Xiaoming Liu ◽  
Zhengjie Yao ◽  
Zhenwei Zhang ◽  
Jiali Li ◽  
Ji Jia ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Covalent Organic Frameworks ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
New Material ◽  
First Time ◽  
Alkyne Coupling

A novel diyne-linked porphyrin-based COF was constructed through palladium catalyzed alkyne-alkyne coupling for the first time. The new material features inherent porosity, moderate crystallinity, excellent durability, full π-conjugation, and can...

Anchored Pd(0) Nanoparticles on Synthetic Talc for the Synthesis of Biaryls and a Precursor of Angiotensin II Inhibitors

Synthesis ◽  
2020 ◽  
Author(s):  
Nelson Luís C. Domingues ◽  
Beatriz F. dos Santos ◽  
Beatriz A. L. da Silva ◽  
Aline R. de Oliveira ◽  
Maria H. Sarragiotto
Keyword(s):  
Angiotensin Ii ◽  
Palladium Catalysts ◽  
Rational Design ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Cost Effective ◽  
Significant Loss ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
Short Time

AbstractThe palladium-catalyzed Suzuki–Miyaura cross-coupling reaction is one of the most important and efficient reactions to prepare a variety of organic compounds, including biaryls. Despite the overwhelming number of reports related to this topic, some methodological difficulties persist in terms of catalyst handling, recovery, and reuse, as well as the reaction media. This work reports the rational design of new, efficient, cost-effective, and reusable palladium catalysts supported on synthetic talc for the Suzuki–Miyaura reaction. From the results, key points were identified: both designed catalysts accelerated the reaction in EtOH and an open-flask setup, affording moderate to excellent yields within a short time (e.g., 30 min) even for deactivated aryl halides; the protocol can be applied to a great number of both cross-coupling partners, showing an excellent functional group tolerance; the catalysts can be recovered and reused without significant loss of activity. This protocol was used for the synthesis of a precursor of angiotensin II inhibitors such as valsartan, losartan, irbesartan, and telmisartan.

Palladium-catalyzed direct reductive cross-coupling of aryltrimethylammonium salts with aryl bromides

2021 ◽  
Author(s):  
Chen Zhang ◽  
Na-Na Ma ◽  
Zi-Lun Yu ◽  
Chuanji Shen ◽  
Xiaocong Zhou ◽  
...  
Keyword(s):  
Palladium Catalyst ◽  
Cross Coupling ◽  
Aryl Bromides ◽  
Palladium Catalyzed

An efficient palladium-catalyzed direct reductive cross-coupling of aryltrimethylammonium salts with aryl bromides was developed. The reactions proceeded smoothly in the presence of palladium catalyst, magnesium turnings, LiCl, and TMEDA in...

scholarly journals Recent Developments in the Suzuki–Miyaura Reaction Using Nitroarenes as Electrophilic Coupling Reagents

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 213 ◽  
Author(s):  
Lou Rocard ◽  
Piétrick Hudhomme
Keyword(s):  
Organic Synthesis ◽  
Palladium Catalyst ◽  
Recent Progress ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Coupling Reagents ◽  
Cross Coupling Reactions ◽  
Recent Developments ◽  
Palladium Catalyzed ◽  
Intense Research

Palladium-catalyzed cross-coupling reactions are nowadays essential in organic synthesis for the construction of C–C, C–N, C–O, and other C-heteroatom bonds. The 2010 Nobel Prize in Chemistry to Richard F. Heck, Ei-ichi Negishi, and Akira Suzuki was awarded for the discovery of these reactions. These great advances for organic chemists stimulated intense research efforts worldwide dedicated to studying these reactions. Among them, the Suzuki–Miyaura coupling (SMC) reaction, which usually involves an organoboron reagent and an organic halide or triflate in the presence of a base and a palladium catalyst, has become, in the last few decades, one of the most popular tools for the creation of C–C bonds. In this review, we present recent progress concerning the SMC reaction with the original use of nitroarenes as electrophilic coupling partners reacting with the organoboron reagent.

Palladium-catalyzed heck and suzuki coupling in glycerol

2007 ◽  
Vol 61 (3) ◽  
Author(s):  
A. Wolfson ◽  
C. Dlugy
Keyword(s):  
Diethyl Ether ◽  
Palladium Catalysts ◽  
Phenylboronic Acid ◽  
Cross Coupling ◽  
Palladium Complexes ◽  
Organic Substrates ◽  
Heck Coupling ◽  
Green Solvent ◽  
Palladium Catalyzed ◽  
Simple Extraction

AbstractThe Heck coupling of halobenzenes with various alkenes and the Suzuki cross coupling of halobenzenes with phenylboronic acid were successfully performed in glycerol as the reaction solvent using homogeneous and heterogeneous palladium catalysts. Glycerol is a renewable and recyclable green solvent that is able to dissolve organic substrates, inorganic bases, and palladium complexes, and that allows easy isolation of the reaction product by simple extraction with glycerol-immiscible solvents such as diethyl ether, hexane, and dichloromethane.

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