Palladium-Catalyzed Domino Reaction Research Articles

Stereoselective Synthesis of Fused Bicyclic Systems via a Palladium-Catalyzed Domino Reaction

Stereoselective Synthesis of Fused Bicyclic Systems via a Palladium-Catalyzed Domino Reaction

Rapid Assembly of Unsymmetrically Linked Bis-heterocycles via Palladium Domino Catalysis.

A palladium-catalyzed domino reaction of alkene-tethered oxime esters is reported. This transformation uses an air-stable palladium precatalyst that initiates a Narasaka-Heck reaction, that is interrupted with a Pd(II)-promoted cyclization. Through this methodology, a novel class of unsymmetrical alkyl-linked bis-heterocycles were synthesized in yields up to 99%. The reaction is scalable up to 1.0 mmol, with simplified purification steps. This transformation expands the scope of accessible bis-heterocycles available through Narasaka-Heck reactions beyond C-H activation and direct anionic capture termination steps.

Computational Determination of the Mechanism of the Palladium-Catalyzed Domino Reaction of ortho-Iodostyrene, Oxanorbornadiene, and Phenylboronic Acid.

The palladium-catalyzed three-component domino reaction of ortho-iodostyrene, 2,3-dicarbomethoxy-7-oxanorbornadiene (ONBD), and phenylboronic acid discovered by the Lautens group provides a convenient method to synthesize indenes derivatives. Herein, density functional theory (DFT) calculations were employed to explore the detailed mechanism of this domino reaction. The computational results suggest that the alkene-insertion-first and the transmetalation-first mechanisms are competitive, and the former mechanism is slightly more favorable because of the difficult intramolecular alkene insertion of the alkyl-PdII-aryl than alkyl-PdII-I complex. Further analysis on substituents of ONBD unveils the impacts of noncovalent interactions and electronic effect on the rate-determining retro-Diels-Alder process. The understanding of this domino reaction has important implications for developing a novel palladium-catalyzed domino reaction with a retro-Diels-Alder strategy.

One-Pot Three-Component Synthesis of Phenanthrenes via Palladium-Catalyzed Catellani and Retro-Diels-Alder Reactions.

An efficient one-pot three-component palladium-catalyzed domino reaction of aryl iodide, 2-bromophenylboronic acid, and norbornadiene to produce phenanthrenes has been developed. Norbornadiene serves both as the activator of ortho-C-H bond and the source of ethylene via a retro-Diels-Alder reaction. The method features inexpensive and readily available substrates, a broad range of functional groups, and good yields.

Recent Advances in the Synthesis of 3,n-Fused Tricyclic Indole Skeletons via Palladium-Catalyzed Domino Reactions.

3,n-fused (n = 4-7) tricyclic indoles are pervasive motifs, embedded in a variety of biologically active molecules and natural products. Thus, numerous catalytic methods have been developed for the synthesis of these skeletons over the past few decades. In particular, palladium-catalyzed transformations have received much attention in recent years. This review summarizes recent developments in the synthesis of these tricyclic indoles with palladium-catalyzed domino reactions and their applications in the total synthesis of representative natural products.

Palladium-Catalyzed Domino Reaction for the Assembly of Norbornane-Containing Chromones with Dimethyl Squarate as the Solid C1 Source.

Reported herein is a novel palladium-catalyzed [2 + 2 + 1] domino annulation of 3-iodochromones, bridged olefins, and dimethyl squarate allowing the construction of chromone-containing polycyclic compounds in good to high yields. Importantly, dimethyl squarate is first employed as the solid C1 source in organic synthesis. Gram-scale experiments, late-stage modification of natural products, as well as transformations of products show potential for further synthetic elaborations.

Reaction of imidazo[1,2-a]pyridines with coumarin-3-carboxylic acids: a domino Michael addition/decarboxylation/oxidation/annulation

A palladium-catalyzed decarboxylative domino reaction of imidazo[1,2-a]pyridines and coumarin-3-carboxylic acids has been developed, which provides access to dibenzoisochromenoimidazo[1,2-a]pyridin-6-ones possessing six fused rings.

Continuous-Flow Synthesis of Isocyanides for Use in a Palladium-Catalyzed Domino Reaction

Continuous-Flow Synthesis of Isocyanides for Use in a Palladium-Catalyzed Domino Reaction

Highly regioselective palladium-catalyzed domino reaction for post-functionalization of BODIPY.

A series of benzo[a]-fused BODIPYs and the corresponding isomeric naphthyl-BODIPYs have been synthesized through a facile one-pot palladium-catalyzed domino reaction of BODIPY precursors (2-bromo-BODIPYs) with diarylethynes, via "cis, cis" and "trans, cis" addition transition states with alkynes, respectively. This reaction exhibits unprecedentedly complete cyclization regioselectivity to the a-position of the BODIPY over the b-one, and the resulting products can be effectively regulated by the substituent choice on the diarylethynes.

A Catellani and retro-Diels–Alder strategy to access 1-amino phenanthrenes via ortho- and interannular C–H activation of 2-iodobiphenyls

A palladium-catalyzed three-component domino reaction for the construction of 1-amino phenanthrene derivatives by ortho- and interannular C–H activation of 2-iodobiphenyls has been developed.

A Palladium-Catalyzed Domino Reaction To Access 3-Amino-2H-indazoles from Hydrazines and 2-Halobenzonitriles.

The development of a novel selective synthesis of 3-amino-2H-indazoles from readily available 2-halobenzonitriles is presented. The reaction proceeds through a domino reaction sequence, consisting of a regioselective palladium-catalyzed coupling of monosubstituted hydrazines with 2-halobenzonitriles, followed by an intramolecular hydroamination through a 5-exo-dig cyclization and subsequent isomerization to directly afford a wide variety of substituted 2H-indazole analogues in good to excellent yields.

Pd-Catalyzed Domino Reactions Involving Alkenes To Access Substituted Indole Derivatives

Palladium-catalyzed domino reactions are advanced tools in achieving various nitrogen-containing heterocycles in an efficient and economical manner due to the reduced number of steps in the process. This review highlights recent advances in domino processes aimed at the synthesis of indole derivatives and polycyclic systems containing the indole nucleus in intra/intra- or intra/intermolecular reactions. In particular, we consider domino processes that involve a double bond in a step of the sequence, which allow the issue of regioselectivity in the cyclization to be faced and overcome. The different sections in this review focus on the synthesis of the indole nucleus and functionalization of the scaffold starting from different substrates that have been identified as activated starting materials, which involve a halogenated moiety or unactivated unsaturated systems. In the former case, the reaction is under Pd(0) catalysis, and in the second case a Pd(II) catalytic species is required and then an oxidant is necessary to reconvert the Pd(0) into the active Pd(II) species. On the other hand, the second method has the advantage that it uses easy available and inexpensive substrates.1 Introduction2 Indole Scaffold Synthesis2.1 Activated Substrates2.2 Unactivated Substrates3 Functionalization of Indole Scaffold3.1 Activated Substrates3.2 Unactivated Substrates4 Conclusions

Synthesis of Phenanthrenes via Palladium-Catalyzed Three-Component Domino Reaction of Aryl Iodides, Internal Alkynes, and o-Bromobenzoic Acids

A new palladium-catalyzed domino alkyne insertion/C–H activation/decarboxylation sequence has been developed, which provides an efficient approach for synthesizing a variety of functionalized phenanthrenes in moderate to good yields. The method shows broad substrate scope and good functional group tolerance by employing readily available materials, including aryl iodides, internal alkynes, and o-bromobenzoic acids, as three-component coupling partners.

2,2-Bifunctionalization of Norbornene in Palladium-Catalyzed Domino Annulation.

A palladium-catalyzed three-component [2 + 3 + 1] domino annulation among 3-iodochromones, α-bromoacetophenones, and norbornene is presented, affording various chromone-containing polycyclic compounds bearing fused/spiro/bridged-ring systems. For the first time, the 2,2-bifunctionalization of norbornene was realized in palladium-catalyzed domino reaction. This cyclization characterizes three new bonds (two C-C and one C-O) in a single operation and produces nontrivial spiro-norbornane fragments in comparison with a traditional palladium-catalyzed process involving norbornene.

One-Pot Synthesis of N-Imidoyl-(1 H)-indoles via Palladium-Catalyzed Oxidative Insertion Domino Reaction with Isocyanide and Arylboronic Acid.

Efficient one-pot synthesis of N-imidoyl-(1 H)-indoles has been described, which is achieved by the palladium-catalyzed oxidative insertion of 2-(phenylethynyl)aniline, arylboronic acid, and isonitrile. This method provides a new way to synthesize N-imidoyl-(1 H)-indoles, which has a wide substrate scope, good functional group tolerance, and mild reaction condition.

Recent Development in Palladium-Catalyzed Domino Reactions: Access to Materials and Biologically Important Carbo- and Heterocycles

The chemistry of palladium complexes has no limits. Many domino processes (even multicomponent) are continuously appearing in the literature. Carbocyclic and heterocyclic molecules are efficiently ...

Synthesis of a Poly-Heterocyclic Tetra-Substituted Alkene via a Palladium-Catalyzed Four-Fold Domino Reaction for the Design of Polymeric Molecular Switches

Synthesis of a Poly-Heterocyclic Tetra-Substituted Alkene via a Palladium-Catalyzed Four-Fold Domino Reaction for the Design of Polymeric Molecular Switches

Palladium-Catalyzed Domino Reaction for Stereoselective Synthesis of Multisubstituted Olefins: Construction of Blue Luminogens.

The first Pd-catalyzed multicomponent reaction of aryl iodides, alkenyl bromides, and strained alkenes has been developed, which allowed us to synthesize a variety of multisubsituted olefins in yields of 45-96% with excellent stereoselectivity. The configuration of the product was controlled by the configuration of the alkenyl bromides. Moreover, this practical methodology employing readily available substrates was found to be tolerant to a wide range of functional groups. Fifty six examples of highly stereoselective tri- or tetrasubstituted olefins have been successfully synthesized via this methodology. Most of the synthesized tetrasubstituted olefins are good aggregation-induced emission (AIE) luminogens.

Palladium-Catalyzed 4-Fold Domino Reaction for the Synthesis of a Polymeric Double Switch.

A palladium-catalyzed 4-fold domino reaction consisting of two carbopalladation reactions and two C-H activation reactions, followed by the introduction of an acrylate moiety, led to the tetra-substituted helical alkene A2, using the dialkyne A3 as a substrate. The alkene was copolymerized with butyl acrylate by using the reversible addition-fragmentation chain transfer polymerization (RAFT) to give the desired polymeric switch A1.

Vinylogous Elimination/Heck Coupling/Allylation Domino Reactions: Access to 2-Substituted 2,3-Dihydrobenzofurans and Indolines.

A highly regio- and stereoselctive palladium-catalyzed domino reaction of functionalized aryl allyl ethers has been developed. Various aryl allyl ethers derived from the phosphine-catalyzed addition of electron-deficient allenes with phenol are found to be efficient substrates for the synthesis of 2-substituted 2,3-dihydrobenzofurans and indolines. It is the first example of aryl allyl ether used as an ideal and practical precursor of hard to get functionalized 1,3-butadiene for the heterocyclic compound synthesis.