[Cp*RhCl2]2 catalyzed three-component coupling cyclization of 2,3-allenoic acids with 2,3-allenols in the presence of Cu(OAc)2•H2O

Review Chemistry, Multidisciplinary

Engaging Yne-Allenes in Cycloaddition Reactions: Recent Developments

Jia-Yin Wang et al.

Summary: This article provides a comprehensive overview of the transformations of yne-allenes, discussing their general and specific reactivities, presenting and commenting on their mechanisms and applications.

CHINESE JOURNAL OF CHEMISTRY (2022)

添加到收藏夹

Article Chemistry, Organic

Synthesis of 2-hydroxytetrahydrofurans by Wacker-type oxidation of 1,1-disubstituted alkenes

Rina Tanaka et al.

Summary: The steric hindrance of 1,1-disubstituted alkenes makes their Wacker-type oxidation challenging. In this study, we successfully demonstrated the stereoselective synthesis of 2-hydroxytetrahydrofurans by utilizing a PdCl2(MeCN)(2)/NO/BQ catalyst system under 1 atm O-2 in H2O or H2O/DMF.

ORGANIC & BIOMOLECULAR CHEMISTRY (2022)

添加到收藏夹

Article Chemistry, Multidisciplinary

Palladium-Catalyzed Silylacylation of Allenes Using Acylsilanes

Tetsuya Inagaki et al.

Summary: We have developed a palladium-catalyzed addition reaction of acylsilanes to unactivated allenes, which exhibits complete regioselectivity and provides a straightforward access to functionalized alkenylsilane derivatives.

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION (2022)

添加到收藏夹

Article Chemistry, Multidisciplinary

Copper-Catalyzed Regiodivergent and Enantioselective Hydrosilylation of Allenes

Jian-Lin Xu et al.

Summary: A copper-catalyzed regiodivergent hydrosilylation of a wide range of simple allenes is reported. Linear and branched allylsilanes can be obtained by choosing suitable solvents. Moreover, high enantioselectivity branch allylsilanes (up to 97% enantiomeric excess) can be achieved in the unprecedented asymmetric allene hydrosilylation with a C2-symmetric bisphosphine ligand.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2022)

添加到收藏夹

Article Chemistry, Multidisciplinary

Asymmetric Total Syntheses of Hypoestin A, Albolic Acid, and Ceroplastol II

Yong-Qiang Wang et al.

Summary: This study achieved the first asymmetric total synthesis of bioactive diterpenoid hypoestin A and the second asymmetric total syntheses of sesterterpenoids albolic acid and ceroplastol II. The challenging and highly functionalized tricarbocyclic ring systems in these natural products were efficiently constructed through a unique intramolecular Pauson-Khand reaction. This work represents the first reported use of the Pauson-Khand reaction to access synthetically challenging eight-membered-ring systems in natural product synthesis.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2022)

添加到收藏夹

Article Chemistry, Organic

Allenes in Diels-Alder Cycloadditions

Henning Hopf et al.

Summary: Allenes have traditionally played a minor role in Diels-Alder cycloadditions, but their importance has grown with their increased availability and unique stereochemical features. This review provides a comprehensive overview of allenes in Diels-Alder processes, covering their application in dienes, dienophiles, and cycloadducts, discussing both inter- and intramolecular cycloadditions, and describing the stereochemical aspects of the addition process. Emerging areas such as the use of allenic components in dehydro-Diels-Alder processes and dendralenic allenes for rapid generation of molecular complexity are also addressed, along with preparatively useful methods for allenic precursor synthesis.

SYNTHESIS-STUTTGART (2022)

添加到收藏夹

Article Chemistry, Multidisciplinary

Catalytic Lewis Base Additive Enables Selective Copper-Catalyzed Borylative α-C-H Allylation of Alicyclic Amines

Borja Perez-Saavedra et al.

Summary: Functionalized alicyclic amines are crucial for synthesizing bioactive compounds and drugs. This study presents a novel copper-catalyzed method for transforming O-benzoyl hydroxylamines into alpha-functionalized cyclic secondary amines, using unique additives to inhibit competing reactions. The method exhibits high selectivity and efficiency.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2022)

添加到收藏夹

Review Chemistry, Organic

Recent advances in the metal-catalyzed asymmetric synthesis of chiral allenes

Wei Xiao et al.

Summary: Chiral allenes, widely present in natural products, bioactive pharmaceuticals, and advanced functional materials, have garnered significant attention from chemists. Recent advances in asymmetric metal-catalyzed synthesis of chiral allenes have provided inspiration for future studies with highlighted challenges and potential areas for improvement.

ORGANIC CHEMISTRY FRONTIERS (2022)

添加到收藏夹

Review Chemistry, Organic

Gold-catalyzed cycloadditions of allenes via metal carbenes

Guang-Qin Gao et al.

Summary: In recent years, gold-catalyzed cycloadditions of allenes, especially those involving a gold carbene intermediate, have gained significant attention for their ability to avoid the use of potentially hazardous and inaccessible starting materials. Cycloaddition reactions, which involve the addition of unsaturated functional groups, are efficient synthetic methods for the rapid construction of carbo- and heterocyclic structures from simple precursors.

ORGANIC & BIOMOLECULAR CHEMISTRY (2022)

添加到收藏夹

Article Chemistry, Multidisciplinary

Allene C(sp2)-H Activation and Alkenylation Catalyzed by Palladium

Benedikt S. Schreib et al.

Summary: In this study, a Pd-catalyzed C-H alkenylation reaction of electronically unbiased allenes was reported, providing penta-1,2,4-triene products in up to 94% yield. The use of picolinamide directing group enabled the formation of allenyl-palladacycles, which subsequently participated in a turnover-limiting Heck-type reaction with electron-deficient alkene coupling partners. Additionally, picolinamide N,O-acetals were introduced as readily removable auxiliaries for C-H activation reactions, facilitating the efficient alkenylation of allenyl carbinol derivatives while maintaining the reactivity of the products.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2021)

添加到收藏夹

Review Chemistry, Multidisciplinary

Deciphering the Chameleonic Chemistry of Allenols: Breaking the Taboo of a Onetime Esoteric Functionality

Jose M. Alonso et al.

Summary: The allene functionality, specifically the allenol, has evolved from a chemical curiosity to a common building block in modern organic chemistry, with unique reactivity and frequent occurrence in naturally systems. This Review highlights the significant contributions to the chemistry of allenols in the past decade, focusing on their synthesis, reactivity, and presence in natural products.

CHEMICAL REVIEWS (2021)

添加到收藏夹

Article Chemistry, Multidisciplinary

Kinetic Resolution of Allyltriflamides through a Pd-Catalyzed C-H Functionalization with Allenes: Asymmetric Assembly of Tetrahydropyridines

Jose Manuel Gonzalez et al.

Summary: This report presents a simple and practical method for enantioselective assembly of tetrahydropyridines, paired with a kinetic resolution of alpha-branched allyltriflamides. Both the chiral allylamide precursors and the tetrahydropyridine adducts were obtained in high yields with excellent enantioselectivity and selectivity values.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2021)

添加到收藏夹

Article Chemistry, Multidisciplinary

Origins of Endo Selectivity in Diels-Alder Reactions of Cyclic Allene Dienophiles

Melissa Ramirez et al.

Summary: The Diels-Alder reactions of furans and pyrroles with 1,2-cyclohexadiene and oxa- and azaheterocyclic analogs exhibit endo selectivity, which is determined by the interaction of molecular orbitals and electrostatic effects. This selectivity, based on stabilizing interactions, is expected to lead to the increased use of strained cyclic allenes in chemical synthesis.

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION (2021)

添加到收藏夹

Article Chemistry, Multidisciplinary

Asymmetric Total Synthesis of Sarpagine and Koumine Alkaloids

Zhao Yang et al.

Summary: In this study, a concise, collective, and asymmetric total synthesis of sarpagine alkaloids and biogenetically related koumine alkaloids has been achieved, starting from L-tryptophan and featuring a rigid cage scaffold. Two key bridged skeleton-forming reactions, the tandem sequential oxidative cyclopropanol ring-opening cyclization and ketone alpha-allenylation, were utilized to assemble the caged sarpagine scaffold and install requisite derivative handles. This approach allowed for the total synthesis of five sarpagine alkaloids and three koumine alkaloids with various substituents and more complex cage scaffolds.

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION (2021)

添加到收藏夹

Article Chemistry, Multidisciplinary

Direct Activation of a Remote C(sp3)-H Bond Enabled by a Visible-Light Photosensitized Allene Moiety

Jiaxin Liu et al.

Summary: It was discovered that the triplet-excited state of allene moiety can be used as a partner for hydrogen-atom-transfer, activating remote sp(3) C-H bonds under mild reaction conditions via visible-light irradiation. This reactivity of allene derivatives under excited state in radical chemistry, previously unexplored, was supported by experiments and calculations.

ANGEWANDTE CHEMIE-INTERNATIONAL EDITION (2021)

添加到收藏夹

Article Chemistry, Multidisciplinary

CuH-Catalyzed Regio- and Enantioselective Hydrocarboxylation of Allenes: Toward Carboxylic Acids with Acyclic Quaternary Centers

Sheng Feng et al.

Summary: A method for preparing alpha-chiral carboxylic acid derivatives, including those with all-carbon quaternary centers, was reported through an enantioselective CuH-catalyzed hydrocarboxylation of allenes with a commercially available fluoroformate. Various heterocycles and functional groups on the allenes were tolerated, resulting in enantioenriched alpha-quaternary and tertiary carboxylic acid derivatives with good yields and exclusive branched regioselectivity. The synthetic utility of this approach was further demonstrated by derivatization of the products to obtain biologically important compounds, such as the antiplatelet drug indobufen.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2021)

添加到收藏夹

Article Chemistry, Organic

Allenes: Versatile Building Blocks in Cobalt-Catalyzed C-H Activation

Rahul K. Shukla et al.

Summary: This article summarizes the role of allenes in cobalt-catalyzed C-H activation reactions and describes their application in the C-8 dienylation reaction.

SYNLETT (2021)

添加到收藏夹

Review Chemistry, Organic

Reactions of Allenes with strong Borane-Based Lewis Acids

Urs Gellrich

Summary: This review focuses on the reactions of allenes with boron-based Lewis acids, particularly those with perfluorophenyl rings. Depending on the substitution patterns, a wide variety of chemical transformations can be observed, including unexpected skeletal rearrangements. Some transformations only require catalytic amounts of borane-based Lewis acid, and mechanistic aspects and similarities in the initial reaction steps are emphasized.

EUROPEAN JOURNAL OF ORGANIC CHEMISTRY (2021)

添加到收藏夹

Article Chemistry, Multidisciplinary

Palladium-Catalyzed Annulations of Strained Cyclic Allenes

Andrew Kelleghan et al.

Summary: The study reports Pd-catalyzed annulations of in situ generated strained cyclic allenes, validating both diastereo- and enantioselective variants. This method is expected to fuel the development of reactions for the synthesis of complex scaffolds by strategically merging transition metal catalysis and transient strained intermediate chemistry.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2021)

添加到收藏夹

Article Chemistry, Multidisciplinary

Regio- and Stereoselective Synthesis of Multi-Alkylated Allylic Boronates through Three-Component Coupling Reactions between Allenes, Alkyl Halides, and a Diboron Reagent

Yu Ozawa et al.

Summary: Multisubstituted allylic boronates are valuable precursors for constructing densely substituted carbon skeletons. The regio- and stereoselective coupling reactions between gem-dialkylallenes, alkyl halides, and a diboron reagent can lead to sterically congested allylic boronates. Computational study revealed that the selectivity-determining mechanism is correlated to the coordination of a boryl copper(I) species to the allene substrate as well as the borylcupration step.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2021)

添加到收藏夹

Article Chemistry, Multidisciplinary

Enantioselective Ruthenium-BINAP-Catalyzed Carbonyl Reductive Coupling of Alkoxyallenes: Convergent Construction of syn-sec,tert-Diols via (Z)-σ-Allylmetal Intermediates

Ming Xiang et al.

Summary: The first catalytic enantioselective ruthenium-catalyzed carbonyl reductive couplings of allene pronucleophiles have been described, leading to the formation of enantiomerically enriched diols. Internal chelation directs the intervention of (Z)-sigma-alkoxyallyl-ruthenium isomers, enabling stereospecific carbonyl addition.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY (2021)

添加到收藏夹

Article Chemistry, Physical

Stereodefined rhodium-catalysed 1,4-H/D delivery for modular syntheses and deuterium integration

Weiyi Wang et al.

Summary: Researchers have proposed a method to prepare 3-methyl-2(E)-enals or -enones from 2,3-allenols and organoboronic acids using a 1,4-H transfer, which is highly stereoselective and straightforward, accommodating various functional groups. This method can efficiently generate deuterated 2(E)-enals or -enones, providing a convenient pathway for the preparation of other deuterated compounds.

NATURE CATALYSIS (2021)

添加到收藏夹

Article Chemistry, Multidisciplinary

Rh-Catalyzed cyclization of 2,3-allenoic acids in the presence of 2,3-allenols

Junjie Fan et al.

Summary: A novel synthetic method was reported for the coupling cyclization of different classes of allenes with 2,3-allenoic acids catalyzed by rhodium, leading to the formation of compounds with important bioactive components. The reaction involved nucleometalation, insertion, and stereodefined 1,4-H delivery processes carried out by the rhodium catalyst.

CHEMICAL COMMUNICATIONS (2021)

添加到收藏夹

Review Chemistry, Multidisciplinary

Recent advances in [3+2] cycloaddition of allenes with 1,3-carbonyl ylides; Rh(ii)-catalyzed access to bridged polyoxocarbocyles

Santosh Kumar Sahu et al.

Summary: This study summarizes the stereochemical outcomes of [3+2] cycloaddition using rhodium carbene-mediated diazo decomposition for highly diastereoselective poly oxacarbocycles formation. Further exploration with other transition metals and ylides is needed for synthesis of bridged polyheterocycles with potential drug candidate structures similar to known compounds like anthecularin, artemisinin, englerin and intracarene. This review presents a future outlook for organic chemists to explore the synthesis of bridged polyheterocarbocycles.

NEW JOURNAL OF CHEMISTRY (2021)

添加到收藏夹

Article Chemistry, Organic

Rh-Catalyzed oxidative homo-coupling cyclization of 2,3-allenols to conjugated furylenones

Xiaoyan Wu et al.

Summary: An unexpected rhodium-catalyzed reaction has been reported for the synthesis of specific compounds with high efficiency, showing great potential for further research and applications.

ORGANIC CHEMISTRY FRONTIERS (2021)

添加到收藏夹

Review Chemistry, Multidisciplinary