Palladium-catalyzed Three-component Reaction Research Articles

Palladium-Catalyzed Three-Component Cascade Carbonylation Reaction to Construct Benzofuran Derivatives.

A novel three-component cyclization carbonylation reaction of iodoarene-tethered propargyl ethers with amine and CO is reported. This palladium-catalyzed cascade reaction undergoes a sequence of oxidative addition, unsaturated bond migration, carbonyl insertion, and nucleophilic attack to deliver the benzofuran skeleton. Both aromatic amines and aliphatic amines could proceed smoothly in this transformation under one atm of CO.

Stereoselective Fluoroalkylacylation of Alkynes via Cooperative N-Heterocyclic Carbene/Palladium Catalysis.

Herein, a cooperative N-heterocyclic carbene- and palladium-catalyzed three-component reaction of alkynes with aldehydes and fluoroalkyl iodides is developed. A series of biologically valuable CF2R-incorporated α-substituted enones was obtained in moderate to good yields. This mild catalytic method exhibits exclusive regio- and stereoselectivity, excellent functional group tolerance, and a broad substrate scope including terminal and internal alkynes. Mechanistic investigations disclose that this alkyne fluoroalkylacylation proceeds via a radical relay process in which vinyl iodides serve as putative reaction intermediates.

Palladium-Catalyzed Tandem Cyclization of Bromoalkynes, Anilines and CO: Access to 1,3-Substituted Maleimides.

A novel palladium-catalyzed three-component carbonylation reaction for the assembly of various 1,3-substituted maleimide derivatives from haloalkynes and simple anilines. The nucleophilic addition reaction of haloalkynes, anilines and CO, and insertion of carbonyl have been achieved sequentially in this reaction. The high chemo- and regioselectivities, as well as no need of expensive ligands or additives further illustrate the synthetic value of this approach.

Stereoselective Synthesis of Substituted (Z)-N-Allyl Sulfonamides via a Palladium-Catalyzed Three-Component Tandem Reaction.

This paper reports the efficient synthesis of substituted (Z)-N-allyl sulfonamides via a palladium-catalyzed three-component tandem reaction of N-buta-2,3-dienyl sulfonamides with iodides and sulfonyl hydrazide or sulfinic acid sodium salt as nucleophiles. Pd(PPh3)4 (2.5 mol %), K2CO3, and THF were used as the optimal catalyst, base, and solvent, respectively. The substituted (Z)-N-allyl sulfonamides were obtained in a 30-83% overall yield. Mechanistic investigations revealed that the formation of the single (Z)-isomer was controlled by the formation of a six-membered palladacycle intermediate.

Palladium-Catalyzed Three-Component Coupling of Benzynes, Benzylic/Allylic Bromides and 1,1-Bis[(pinacolato)boryl]methane

We report herein a palladium-catalyzed three-component cross-coupling reaction of 2-(trimethylsilyl)phenyl trifluoromethanesulfonate, benzylic/allylic bromides and 1,1-bis[(pinacolato)boryl]methane. The reaction, which affords benzyl boronates as the products, represents the first example of using 1,1-bis[(pinacolato)boryl]methane in a cross-coupling reaction involving benzyne species.

Synthesis of Indenes and Benzofulvenes via a Palladium-Catalyzed Three-Component Reaction

Synthesis of Indenes and Benzofulvenes via a Palladium-Catalyzed Three-Component Reaction

Palladium-Catalyzed Three-Component 1,4-Alkoxyarylation Reaction of [60]Fullerene.

The palladium-catalyzed three-component alkoxyarylation reaction of [60]fullerene with primary/secondary alcohols and aryl iodides generates a series of 1,4-(alkoxy)(aryl)[60]fullerene derivatives. Plausible reaction pathways for the formation of 1,4-(alkoxy)(aryl)[60]fullerenes are proposed. In addition, the electrochemical properties of the synthesized 1,4-alkoxyarylation adducts are investigated.

4 + 1 + 1] Tandem Cyclization Reaction Involving Isocyanides: Access to 2-(Trifluoromethyl)quinazolin-4(3H)-imines

A palladium-catalyzed three-component reaction of isocyanides, 2,2,2-trifluoro-N-(2-iodophenyl)acetimidoyl chlorides, and amines for the one-pot synthesis of 2-(trifluoromethyl)quinazolin-4(3H)-imines was described. The protocol features a wide substrate scope, high efficiency, and readily available raw materials.

Palladium-Catalyzed Carbene Migratory Insertion/Carbonylation Cascade Reaction: Synthesis of 2-Indolones with a C3 All-Carbon Quaternary Center.

An attractive palladium-catalyzed three-component reaction of ortho-amino aryl diazo esters, allyl carboxylates, and carbon monoxide (CO) has been developed. This catalytic system rendered domino carbene migratory insertion and carbonylation. Remarkably, 2-indolones 3 with a C3 all-carbon quaternary center can be selectively obtained in good to excellent yields via one-pot synthesis, in which two different C-C bonds and one C-N bond were formed in a straightforward manner.

Palladium-Catalyzed Three-Component Cascade Reaction of Nitriles: Synthesis of 2-Arylquinoline-4-carboxylates.

A new method for converting easy availability starting materials 2-(2-oxoindolin-3-yl)acetonitrile, arylboronic acids, and alcohols into 2-arylquinoline-4-carboxylates is reported. The procedure involves a three-component addition/ring expansion/esterification reaction in the presence of Pd(II) catalyst with high functional group tolerance under mild conditions. In addition, the photophysical properties of the resulting product were investigated and exhibited excellent polarity-sensitive fluorescence properties and AIE property.

Palladium-Catalyzed Cascade Carbonylative Synthesis of 1,2,4-Triazol-3-ones from Hydrazonoyl Chlorides and NaN3.

A palladium-catalyzed three-component carbonylative reaction for the synthesis of 3H-1,2,4-triazol-3-ones from hydrazonoyl chlorides and NaN3 has been achieved. The reaction presumably proceeds through a cascade carbonylation, acyl azide formation, Curtius rearrangement, and intramolecular nucleophilic addition sequence. A wide variety of structurally diverse 3H-1,2,4-triazol-3-ones were constructed in moderate to excellent yields. Benzene-1,3,5-triyl triformate (TFBen) was applied as a solid and convenient CO surrogate.

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.

Synthesis of (Z)-Alkene-Containing Linear Conjugated Dienyl Homoallylic Alcohols by a Palladium-Catalyzed Three-Component Reaction

A synthesis of (Z)-alkene-containing linear conjugated dienyl homoallylic alcohols by using a palladium-catalyzed three-component reaction has been developed. This method shows good functional-group compatibility and generality, with high diastereoselectivity. Additionally, in many cases, the present method controls the alkene stereochemistry of the newly formed C–C bond and overcomes the inherent preference for (E)-alkene formation, giving (Z,E)- and (Z,Z)-products.

Understanding the Chemoselectivity in Palladium-Catalyzed Three-Component Reaction of o-Bromobenzaldehyde, N-Tosylhydrazone, and Methanol.

To understand the ligand-controlled palladium-catalyzed coupling of o-bromobenzaldehyde, N-tosylhydrazone, and methanol to give methyl 2-benzylbenzoic ester or methyl ether, we herein investigated the mechanisms which account for how C-C and C-O bonds are formed and why bidentate dppf/dppb ligands afford ester, whereas P(o-tolyl)3 ligand gives ether. The ester chemoselectivity of the bidentate ligands is attributed to the strong electron-donating effect that disfavors the C,Br-reductive elimination of the coupling intermediate of o-bromobenzaldehyde and N-tosylhydrazone.

Palladium-Catalyzed Three-Component Coupling Reaction of o-Bromobenzaldehyde, N-Tosylhydrazone, and Methanol.

A ligand-controlled palladium-catalyzed three-component reaction of o-bromobenzaldehyde, N-tosylhydrazone, and methanol is described. This reaction uses readily available compounds as starting materials while displaying a broad substrate scope and good functional group compatibility.

Palladium-catalyzed three-component carbonylative synthesis of 2-(trifluoromethyl)quinazolin-4(3H)-ones from trifluoroacetimidoyl chlorides and amines

An efficient and practical approach for the synthesis of 2-(trifluoromethyl)quinazolin-4(3H)-ones through palladium-catalyzed three-component carbonylative reaction has been developed.

Pd-Catalyzed one-pot synthesis of vinylsilanesviaa three-component tandem reaction

A palladium-catalyzed three-component tandem reaction for stereoselective assembly of various tri- or tetrasubstituted vinylsilanes is established.

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.

Isocyanide Reactions Toward the Synthesis of 3-(Oxazol-5-yl)Quinoline-2-Carboxamides and 5-(2-Tosylquinolin-3-yl)Oxazole.

A palladium-catalyzed three-component reaction between 5-(2-chloroquinolin-3-yl) oxazoles, isocyanides, and water to yield 3-(oxazol-5-yl)quinoline-2-carboxamides is described. Interestingly, sulfonylation occurred when the same reaction was performed with toluenesulfonylmethyl isocyanide (TosMIC) as an isocyanide source. The reaction with 5-(2-chloroquinolin-3-yl)oxazoles and TosMIC in the presence of Cs2CO3 in DMSO afforded 5-(2-Tosylquinolin-3-yl)oxazoles. In basic media, TosMIC probably decomposed to generate Ts− species, which were replaced with Cl−. Tandem oxazole formation with subsequent sulfonylation of 2-chloroquinoline-3-carbaldehydes to form directly 5-(2-tosylquinolin-3-yl)oxazoles was also investigated.

A palladium-catalyzed three-component cascade S-transfer reaction in ionic liquids

A palladium-catalyzed three component cascade S-transfer reaction for the assembly of functionalized 4-sulfenylisoxazoles in ionic liquids was described.