Xiaoming Jie

Visible-light-driven Ru-catalyzed terminal alkene isomerization to 2-alkenes proceeds under N-ligand- and solvent-free conditions with low catalyst loading and excellent scalability.

Phosphine redox catalysis enables trans -selective semireduction of activated alkynes with (deuterated)water as the hydrogen source.

Telescoping synthesis represents a powerful strategy for the rapid assembly of complex molecular scaffolds, while obviating the need for isolation and purification of intermediates, making this strategy particularly appealing in modern synthetic efforts targeting pharmaceuticals and natural products. In this study, we present a rhodium-catalyzed ortho-C(sp²)-H olefination of tert-alkyl aryl ketones with methyl acrylate, followed by cascade double cyclizations that efficiently produce rare γ-lactone-fused indanones. The sequential rearrangement-cyclizations proceed through acid-promoted, carbonyl 1,3-transposition and 1,2-alkyl migration of tert-alkyl substituents to the enone β-carbon.

A metal-free and simple method for the straightforward synthesis of catechols via acid-regulated multiple reactivity modes of TEMPO (oxygenation and desaturation).

Polyfunctionalized arenes are privileged structural motifs in both academic and industrial chemistry. Conventional methods for accessing this class of chemicals usually involve stepwise modification of phenyl rings, often necessitating expensive noble metal catalysts and suffering from low reactivity and selectivity when introducing multiple functionalities. We herein report dehydrogenative synthesis of N -functionalized 2-aminophenols from cyclohexanones and amines. The developed reaction system enables incorporating amino and hydroxyl groups into aromatic rings in a one-shot fashion, which simplifies polyfunctionalized 2-aminophenol synthesis by circumventing issues associated with traditional arene modifications. The wide substrate scope and excellent functional group tolerance are exemplified by late-stage modification of complex natural products and pharmaceuticals that are unattainable by existing methods. This dehydrogenative protocol benefits from using 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) as oxidant that offers interesting chemo- and regio-selective oxidation processes. More notably, the essential role of in situ generated water is disclosed, which protects aliphatic amine moieties from overoxidation via hydrogen bond–enabled interaction.

Hydroboration of styrene or vinylcyclohexane with the IMes(C₆F₅)BH⁺ cation followed by deprotonation provided a convenient synthetic entry to the [B]=CHCH₂R boraalkenes 9 a and 9 b. The in situ generated IMes(SCN)BH⁺ system reacted similarly with 1,1‐diphenylethene followed by deprotonation to give the isothiocyanato substituted boraalkene 9 c. The boraalkenes underwent [2+2] cycloaddition reactions with a small series of heterocumulenes to give the respective four‐membered heterocycles. The [B]=CHCH₂R+CO₂ cycloadducts 13 a and 13 b added the borane HB(C₆F₅)₂ with cleavage of the central B−C σ‐bond. CS₂ underwent an unusual reaction with the boraalkenes, namely insertion into the B=C bond with formation of the borylated dithioketene acetal under complete rupture of the strong B=C double bond. The intermediate dithiobora‐β‐lactone type intermediate was isolated in the case of the isothiocyanato‐boraalkene reaction and characterized by X‐ray diffraction.

Hydroboration of styrene or vinylcyclohexane with the IMes(C₆F₅)BH⁺ cation followed by deprotonation provided a convenient synthetic entry to the [B]=CHCH₂R boraalkenes 9 a and 9 b. The in situ generated IMes(SCN)BH⁺ system reacted similarly with 1,1‐diphenylethene followed by deprotonation to give the isothiocyanato substituted boraalkene 9 c. The boraalkenes underwent [2+2] cycloaddition reactions with a small series of heterocumulenes to give the respective four‐membered heterocycles. The [B]=CHCH₂R+CO₂ cycloadducts 13 a and 13 b added the borane HB(C₆F₅)₂ with cleavage of the central B−C σ‐bond. CS₂ underwent an unusual reaction with the boraalkenes, namely insertion into the B=C bond with formation of the borylated dithioketene acetal under complete rupture of the strong B=C double bond. The intermediate dithiobora‐β‐lactone type intermediate was isolated in the case of the isothiocyanato‐boraalkene reaction and characterized by X‐ray diffraction.

This review describes methods for the synthesis of alkenes by elimination, with a specific focus on α,β-dehydrogenation reactions. It covers the literature published in the period 2011 to early 2020, providing an overview of recently developed transition-metal-catalyzed methods for α,β-desaturation of carbonyl compounds (e.g., ketones, aldehydes, esters, amides, etc.) as well as other functional groups. Key methods covered include palladium-catalyzed dehydrogenation via β-hydride elimination and copper-catalyzed desaturation via a radical pathway, as well as other miscellaneous methods. These approaches provide efficient access to α,β-unsaturated carbonyl compounds, which are important intermediates in the synthesis of diverse valuable organic molecules.

1,2,4,5‐Tetrakis(trimethylsilylethynyl)benzene reacted with two molar equivalents of the boranes R−B(C₆F₅)₂ (R=C₆F₅, Me, Ph) in a series of sequential 1,1‐carboboration reactions to give ca. 1 : 1 mixtures of the two‐fold benzannulated products, namely the respective C_2h and C_2v symmetric tetra‐silyl, bis‐boryl substituted anthracenes. Their active B(C₆F₅)₂ substituents were used for consecutive Suzuki‐Miyaura C−C coupling reactions to give boron‐free phenyl or 2‐pyridyl substituted anthracene products.