Palladium-Catalyzed Intermolecular Oxyvinylcyclization of Alkenes with Alkynes: An Approach to 3-Methylene γ-Lactones and Tetrahydrofurans

Palladium-Catalyzed Oxidative Annulation Leading to Substituted Pyrrolo[3,2,1-jk]carbazoles by Sequential C-N and C-C Bond Formation

A novel regioselective annulation of propargylic alcohols with simple carbazoles for the construction of [3,2,1-jk]carbazole scaffolds is described to be the first example of intermolecular synthesis of [3,2,1-jk]carbazoles from simple carbazoles. In situ synthesis of propargyl alcohols from simple, cheap, and easily accessible ketones has also been developed during the one-pot synthesis of [3,2,1-jk]carbazoles.

Palladium-catalyzed Lewis acid-regulated cascade annulation of alkynes with unactivated alkenes to access diverse α-methylene-γ-lactones

A palladium-catalyzed Lewis acid-regulated cascade annulation of alkynes with unactivated alkenes for the preparation of alkyl substituted α-methylene-γ-lactones with excellent Z/E selectivities was accomplished.

A Construction of α-Alkenyl Lactones via Reduction Radical Cascade Reaction of Allyl Alcohols and Acetylenic Acids

An iron-catalyzed cascade reaction of radical reduction of allyl alcohols and acetylenic acids to construct polysubstituted α-alkenyl lactones has been developed. In this paper, various allyl alcohols can form allyl ester intermediates and are further transformed into alkyl radicals, which form products through intramolecular reflex-Michael addition. In addition, this method can be used to prepare spirocycloalkenyl lactones. Interestingly, this protocol can be used to synthesize the skeleton structure of natural products. Moreover, the product can be further transformed into a β-methylene tetrahydrofuran and tetrahydrofuran diene.

Palladium-Catalyzed Regioselective Syn-Chloropalladation-Olefin Insertion-Oxidative Chlorination Cascade: Synthesis of Dichlorinated Tetrahydroquinolines

A palladium catalyzed cascade process involving syn-chloropalladation, intramolecular olefin insertion, and oxidative C-Cl bond formation reactions was demonstrated for the synthesis of dichlorinated tetrahydroquinolines in high yields (up to 93%). The N-propargyl arylamines having a tethered α,β-unsaturated carbonyl moiety underwent a regioselective syn-chloropalladation followed by a Heck-type reaction to deliver the tetrahydroquinoline scaffold. The rare insertion of the second chlorine atom was rationalized comprising a Pd^II/IV catalytic cycle and oxidative cleavage of the C-Pd^II bond.

Palladium-catalyzed cascade carboesterification of norbornene with alkynes

An efficient and convenient palladium-catalyzed cascade carboesterification of norbornenes (NBE) with alkynes has been accomplished to afford functionalized α-methylene γ-lactone and tetrahydrofuran derivatives in good to excellent yields. This new strategy exhibits excellent atom- and step-economy, good functional group tolerance and broad substrate scope. In particular, NBE-palladium species was proposed to be the key intermediate in the catalytic cycle to suppress the β-H elimination process. Notably, the developed protocol provides a straightforward and practical tool for the construction of diverse oxygen-containing heterocycle frameworks, illustrating a promising application in synthetic and pharmaceutical chemistry.

Palladium-catalyzed highly diastereoselective cascade dihalogenation of alkyne-tethered cyclohexadienones via Umpolung of palladium enolate

A highly regio- and diastereoselective Pd(ii)-catalyzed cascade dihalogenation of alkyne-tethered cyclohexadienones proceeding via an electrophilic oxa-π-allyl palladium-species was demonstrated.

Recent Developments in Pd(0)-Catalyzed Alkene Carboheterofunctionalization Reactions

This review summarizes recent developments in palladium-catalyzed alkene carboalkoxylation and carboamination reactions. New synthetic methods that have been reported in the past four years are described, along with mechanistic issues and the influence of mechanism on product stereochemistry. The applications of these transformations to the synthesis of natural products and other biologically relevant compounds are also discussed.

Palladium-catalyzed cascade reaction of haloalkynes with unactivated alkenes for assembly of functionalized oxetanes

A novel and efficient Pd-catalyzed intermolecular oxidative carboetherification of haloalkynes with unactivated alkenes for constructing functionalized oxetanes has been demonstrated.

MnO2-promoted carboesterification of alkenes with anhydrides: a facile approach to γ-lactones

A new radical cyclization method for the formation of C(sp³)–C(sp³) and C–O bonds via MnO₂-promoted alkene carboesterification with anhydrides is developed.

Iridium-Catalyzed Asymmetric Ring-Opening of Oxabenzonorbornadienes with N-Substituted Piperazine Nucleophiles

Iridium-catalyzed asymmetric ring-opening of oxabenzonorbornadienes with N-substituted piperazines was described. The reaction afforded the corresponding ring-opening products in high yields and moderate enantioselectivities in the presence of 2.5 mol % [Ir(COD)Cl]₂ and 5.0 mol % (S)-p-Tol-BINAP. The effects of various chiral bidentate ligands, catalyst loading, solvent, and temperature on the yield and enantioselectivity were also investigated. A plausible mechanism was proposed to account for the formation of the corresponding trans-ring opened products based on the X-ray structure of product 2i.

Palladium-Catalyzed Desulfitative Oxidative Coupling between Arenesulfinic Acid Salts and Allylic Alcohols: A Strategy for the Selective Construction of β-Aryl Ketones and Aldehydes

An efficient palladium-catalyzed desulfitative oxidative coupling of sodium arylsulfinites for highly region-selective Heck-type reaction of allylic alcohols has been developed. The compatibility of the functionalities of -I, -Br, and -F would explore further postfunctionalization of the C-X bonds. This method provides a new and straightforward protocol for the synthesis of β-aryl ketones and aldehydes. The deuterium labeling experiments indicated that this transformation may proceed via a [1, 2-H] shift process.

Palladium-catalyzed highly regioselective 6-exo-dig cyclization and alkenylation of ortho-ethynylanilides: the synthesis of polyene-substituted benzo[d][1,3]oxazines

A Pd-catalyzed highly regioselective 6-exo-dig cyclization/alkenylation reaction of ortho-ethynylanilides has been developed.

Crystal structure, magnetic and catalytic oxidation properties of manganese(iii) tetrakis(ethoxycarbonyl)porphyrin

5,10,15,20-tetrakis(ethoxycarbonyl)porphyrin manganese(iii) chloride (Mn^IIITECPCl) existed as a Mn–O coordinated dimer. Mn^IIITECPCl gave high yield in oxidation of styrene by using TBHP or PhIO oxidant and was found recyclable.

Oxidative acylation of sulfoximines with methylarenes as an acyl donor

An efficient direct oxidative acylation of sulfoximines with methylarenes as an acyl donor was finally achieved.

Palladium-catalysed oxidative cross-esterification between two alcohols

Oxidative cross-esterification between two alcohols was achieved by using PdCl₂(PPh₃)₂ as the sole catalyst and benzyl chloride as the oxidant.

CuX2-mediated oxybromination/aminochlorination of unsaturated amides: synthesis of iminolactones and lactams

A CuX₂-mediated halocyclization of γ,δ-unsaturated amides for the synthesis of functionalized iminolactones and lactams respectively is described.

Palladium-catalyzed aerobic oxidative double allylic C–H oxygenation of alkenes: a novel and straightforward route to α,β-unsaturated esters

We reported a strategically distinct approach to synthesize α,β-unsaturated esters through palladium-catalyzed aerobic oxidative double allylic C–H oxygenation of alkenes.

A facile approach to synthesize 3,5-disubstituted-1,2,4-oxadiazoles via copper-catalyzed-cascade annulation of amidines and methylarenes

A tandem Cu-catalyzed oxidation–amination–cyclization reaction for synthesizing various 3,5-disubstituted-1,2,4-oxadiazoles from easily available amidines and methylarenes or methylhetarenes is reported.