Article
Chemistry, Multidisciplinary
Olaya Bernardo, Silvia Gonzalez-Pelayo, Israel Fernandez, Luis A. Lopez
Summary: The gold-catalyzed reaction of propargyl esters with alkynylsilanes produces vinylallene derivatives through consecutive [1,2]-acyloxy/[1,2]-silyl rearrangements. This transformation features good yields, full atom-economy, a broad substrate scope, easy scale-up, and low catalyst loadings. The reaction mechanism involves the generation of a gold vinylcarbene intermediate and a type II-Dyotropic rearrangement involving the silyl group and the metal fragment.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Xiayan Y. Zhang, Yi Tong, Gang Li, Hao Zhao, Guanye Chen, Hongliang Yao, Rongbiao Tong
Summary: This article reports an unexpected discovery of a formal 1,5-allyl shift method and provides a mechanistic explanation. This method shows potential applications in organic synthesis and materials chemistry.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Cristina Cheibas, Nicolas Fincias, Nicolas Casaretto, Julian Garrec, Laurent El Kaim
Summary: The Passerini-Smiles reactions of alpha-ketophosphonates with nitrophenols have been studied, revealing complex cascades involving multiple Smiles transfers and phospha-Brook rearrangement. The use of 4-nitrophenols leads to a rare 1,3-Truce-Smiles rearrangement, while 2-nitro derivatives show a different reactivity pattern possibly due to a nitro to nitroso conversion followed by a sigma-pi metathesis. DFT calculations support the proposed mechanisms for both families of adducts, and the potential of this work is further demonstrated by alternative starting materials and the discovery of new aza-Nazarov access.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Biochemistry & Molecular Biology
Bagrat A. Shainyan
Summary: In this study, the concept of anchimeric assistance is examined in the case of primary cations with different heteroatomic substituents in the alpha-position. The migration of either X or Y group to the cation center can stabilize the cation. The migration can be complete, resulting in the formation of a secondary carbocation, or incomplete, leading to an anchimerically assisted iranium ion. The ability of anchimeric assistance and the conformation of the starting carbocation determine the occurrence of these transformations.
Article
Chemistry, Organic
Henning J. Loui, Christoph Schneider
Summary: This study reports the first enantioselective allenylation of Pd enolates enabled by cooperative Pd/Bronsted acid catalysis using beta-keto esters and propargyl alcohols. The enantioselectivity is solely derived from a chiral metal enolate generated in-situ in an open transition state, with no additional binding of the propargyl component to the catalyst. A broad substrate scope was established, providing previously inaccessible products with high yields and excellent enantioselectivities (up to >99:1 e.r.).
Review
Biochemistry & Molecular Biology
Timothy D. Lash
Summary: The unique environment within the core of carbaporphyrinoid systems allows exploration of unusual organometallic chemistry. Metalation with transition metal cations results in derivatives with different physical and chemical properties. The past thirty years have seen significant advances in synthetic routes to carbaporphyrinoid ligands and remarkable organometallic chemistry.
Article
Chemistry, Organic
Peter Langer
Summary: This article discusses the reactions and applications of the dianion of 1,1-diphenylacetone. A new allene synthesis was serendipitously discovered through the study of the regioselectivity of these reactions. Additionally, the reactions of allene dianions with various electrophiles have been investigated.
Article
Chemistry, Organic
Fabio Cuzzucoli, Leanne Racicot, John F. Valliant, Graham K. Murphy
Summary: A new class of fluorinated, cyclic N-methoxyimidates was synthesized through intramolecular fluorocyclization. The reaction achieved efficient cyclization at room temperature using unsaturated amides, a mono-fluoroiodane, and HFIP as the activator, resulting in products with up to 81% yield in a single step. Two product isomers were selectively obtained depending on the presence of an α-arene substituent.
Article
Chemistry, Organic
Yun-Qian Zhang, You-Qin Jiang, Yong-Hao Wang, Cong Qi, Yong Ling, Yanan Zhang, Gong-Qing Liu
Summary: This study reports the three-component selenofunctionalization processes of olefins, diselenides, and sulfonamides using FP-OTf as a reaction promoter. Under optimal conditions, a wide range of vicinally functionalized selenide derivatives can be obtained with high yields and excellent functional group compatibilities. Mechanistic studies indicate that FP-OTf plays a key role in this selenofunctionalization process.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Multidisciplinary Sciences
Xiu Lin, Shi-Nan Zhang, Dong Xu, Jun-Jun Zhang, Yun-Xiao Lin, Guang-Yao Zhai, Hui Su, Zhong-Hua Xue, Xi Liu, Markus Antonietti, Jie-Sheng Chen, Xin-Hao Li
Summary: The research utilizes electron-deficient W2C nanocrystal-based electrodes to enhance the activation of C-H bonds, achieving high turnover frequency and relatively low working potential. The electrocatalytic strategy enables efficient deprotonation processes and boosts hydrogen production, meeting the requirements of sustainable chemical synthesis.
NATURE COMMUNICATIONS
(2021)
Article
Chemistry, Organic
Subhadip Jana, Benedict J. Elvers, Sebastian Patsch, Pallavi Sarkar, Ivo Krummenacher, Mithilesh Kumar Nayak, Avijit Maiti, Nicolas Chrysochos, Swapan K. Pati, Carola Schulzke, Holger Braunschweig, Cem B. Yildiz, Anukul Jana
Summary: We developed a new method for synthesizing different quinodimethane derivatives by oxidizing bis-N-heterocyclic olefins linked by pi-conjugated aromatic spacers. Stable diimidazolium para- and ortho-quinodimethane derivatives were obtained with para- and ortho-phenylene bridges, as well as with tetrafluoro-p-phenylene and p-anthracene spacers. The influence of imidazolium substituents on the air and moisture stability of the quinodimethane derivatives was emphasized. Different electron transfer processes were observed depending on the pi-conjugated aromatic spacer used, with two one-electron or one two-electron redox transitions between bis-N-heterocyclic olefins and diimidazolium-quinodimethanes. The formation of pi-conjugated radical-cations, which are transient redox intermediates, was confirmed by EPR investigation.
Article
Chemistry, Organic
Hongjun Jeon, Sang Won Choi, Soojun Park, Seokwoo Lee, Sanghee Kim
Summary: In this study, a facile method for generating O-acyloxocarbenium ions (AOIs) from ester and acetal groups was presented, resulting in a unique bridged bicyclic system. The proposed mechanism for the reaction was based on experimental and computational studies, revealing the formation pathway through an epoxonium-like transition state.
Article
Chemistry, Multidisciplinary
Lachlan Sharp-Bucknall, Tania, Jason L. Dutton
Summary: This article describes the synthesis and structural characterization of NO2-PhI(OTf)(2), a compound that is resistant to decomposition and has higher reactivity than previously misidentified PhI(OTf)(OAc), confirming the non-existence of PhI(OTf)(2) as an intermediate in oxidation reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Changcheng Jing, Benjamin T. Jones, Ross J. Adams, John F. Bower
Summary: Unique examples of aza-Heck-based C(sp3)-H functionalization cascades are described, where alkyl-Pd(II) intermediates generated from the aza-Heck-type cyclization of N-(pentafluorobenzoyloxy)carbamates undergo C(sp(3))-H palladation to form cyclopropanes. The key factors controlling the site selectivity of the cyclopropanation process have been elucidated, enabling selective access to a wide range of ring- or spiro-fused systems.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Wenqiang Zhou, Song Xi, Haohua Chen, Dan Jiang, Jiao Yang, Shuangwei Liu, Ling He, Hanyue Qiu, Yu Lan, Min Zhang
Summary: Bridged frameworks are important in chemistry and biology, found commonly in pharmaceuticals and natural products. Traditional methods of building these rigid segments at the middle or late stage of synthesis decrease efficiency and specificity. In this study, a novel strategy was used to construct a morphan core equipped with an allene/ketone group through an enantioselective a-allenylation of ketones. The resulting bridged backbone guided the assembly of up to five fusing rings, and the allene and ketone groups allowed precise installation of various functionalities, leading to a concise total synthesis of nine strychnan alkaloids.
Article
Chemistry, Multidisciplinary
Zhitong Zheng, Youliang Wang, Xu Ma, Yuxue Li, Liming Zhang
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Chemistry, Organic
Ting Li, Yuhan Yang, Baomin Luo, Bo Li, Luyi Zong, Weiguang Kong, Hao Yang, Xinpeng Cheng, Liming Zhang
Article
Chemistry, Organic
Ke Zhao, Yu-Chen Hsu, Ziguang Yang, Rai-Shung Liu, Liming Zhang
Review
Chemistry, Multidisciplinary
Zhitong Zheng, Xu Ma, Xinpeng Cheng, Ke Zhao, Kaylaa Gutman, Tianyou Li, Liming Zhang
Summary: Homogeneous gold catalysis has seen significant development since the turn of the millennium, with oxidative gold catalysis being a vibrant subfield delivering valuable synthetic methods. This comprehensive review covers the mechanistic aspects, oxidants, and synthetic applications of oxidative gold catalysis.
Article
Chemistry, Physical
Ting Li, Xinpeng Cheng, Pengcheng Qian, Liming Zhang
Summary: Through cooperative gold catalysis enabled by a special ligand, intramolecular asymmetric functionalization of unactivated propargylic C-H bonds has been achieved, yielding chiral cyclopentane/cyclohexane-fused homopropargylic alcohols with excellent enantiomeric excesses. The reaction shows a broad scope, high stereoselectivity and is realized under mild reaction conditions. Density functional theory studies support the reaction mechanism and confirm metal-ligand cooperation.
Article
Chemistry, Multidisciplinary
Xu Ma, Zhitong Zheng, Yue Fu, Xijun Zhu, Peng Liu, Liming Zhang
Summary: This study introduces a strategy for the formation of 1,2-cis-glycosidic linkage using gold catalysis, achieving excellent yields and outstanding selectivities under mild conditions. This strategy is also successfully applied to the synthesis of oligosaccharides.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Multidisciplinary
Xinpeng Cheng, Tianyou Li, Kaylaa Gutman, Liming Zhang
Summary: This study successfully synthesized alpha,beta-Butenolides with high enantiomeric excess using a novel Cu(I)-ligand cooperative catalysis, highlighting the importance of cooperation between the metal center and the ligand basic amino group. Moreover, it was found that other coinage metals such as Ag and Au can also play a similar role in this asymmetric isomerization chemistry.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Article
Chemistry, Organic
Xinpeng Cheng, Liming Zhang
Summary: This work describes an asymmetric gold-ligand cooperative catalysis for the transformation of readily accessible chiral/achiral propargylic sulfonamides into chiral 3-pyrrolines. A bifunctional biphenyl-2-ylphosphine ligand containing a chiral tetrahy-droisoquinoline fragment is crucial for the observed metal-ligand cooperation and asymmetric induction. The reaction can provide 2,5-cis-3-pyrrolines with excellent diastereoselectivities in a matched scenario, and 2,5-trans-3-pyrrolines with >5/1 diastereoselectivity in a mismatched scenario using the ligand enantiomer. The synthetic utilities of this chemistry have been demonstrated.
Article
Chemistry, Multidisciplinary
Ke Zhao, Philip Kohnke, Ziguang Yang, Xinpeng Cheng, Shu-Li You, Liming Zhang
Summary: A gold(I)-catalyzed enantioselective dearomatization is achieved through metal-chiral ligand cooperation. A new and divergent synthesis of chiral bifunctional binaphthyl-2-ylphosphines is developed for rapid access to these ligands, enabling broad substrate scope. The selective acceleration of one enantiomer formation is achieved through hydrogen bonding between substrate and ligand remote basic group, leading to enantiomeric excesses up to 98%.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Xu Ma, Yongliang Zhang, Xijun Zhu, Yongliang Wei, Liming Zhang
Summary: This work introduces a novel catalytic S(N)2 glycosylation method using an amide-functionalized 1-naphthoate platform as a latent glycosyl leaving group. The amide group facilitates the S(N)2 process by directing the attack of the glycosyl acceptor via H-bonding interaction, resulting in stereoinversion at the anomeric center. Additionally, the amide group enables a safeguarding mechanism by trapping oxocarbenium intermediates, minimizing stereorandom S(N)1 processes. This strategy allows for high-yielding synthesis of a wide range of glycosides with stereoinversion, including challenging 1,2-cis-linkage-rich oligosaccharides.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2023)
Article
Chemistry, Organic
Philip Kohnke, Liming Zhang
Summary: Expedient access to bridged enol benzoates is achieved through a tandem gold-catalyzed cycloisomerization of enynyl esters and the Diels-Alder reaction. The gold catalysis enables the use of enynyl substrates without additional propargylic substitution and results in highly regioselective formation of less stable cyclopentadienyl esters. The regioselectivity is facilitated by a bifunctional phosphine ligand with a remote aniline group that promotes alpha-deprotonation of a gold carbene intermediate. The reaction is applicable to different alkene substitution patterns and various dienophiles.
Article
Chemistry, Multidisciplinary
Yongliang Zhang, Ke Zhao, Xinyi Li, Carlos D. Quintanilla, Liming Zhang
Summary: By using a chiral bifunctional phosphine ligand, a highly efficient and enantioselective dearomatization of phenols is achieved through metal-ligand cooperation. The reaction shows great generality by allowing substitutions at various positions of benzene, including electron-withdrawing groups and carbon-based groups. Spirocyclohexadienone-pyrrol-2-ones, spirocyclohexadienone-butenolides, and spirocyclohexadenone-cyclopentenones are formed in high yields and with high enantioselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Carlos D. D. Quintanilla, Ke Zhao, Liming Zhang
Summary: By combining tandem asymmetric gold catalysis and subsequent stereoconvergent hydrolysis, hydroxylated propargylic esters are transformed into chiral β-oxygenated ketones with good enantiomeric ratios and high yields. The chiral center of the product is formed through stereoselective cyclization of a hydroxylated allenyl ester intermediate facilitated by asymmetric gold-ligand cooperation.
Review
Chemistry, Multidisciplinary
Zhao Ke, Hong Zhi, Zhang Liming
Summary: Homogeneous asymmetric gold catalysis has experienced significant development since 2005 and has been extensively applied in organic synthesis. In recent years, the development of chiral functionalized biaryl-2-ylphosphine ligands has opened up new approaches for achieving asymmetric gold catalysis, focusing on the enabling interactions between ligand functional groups and substrates.
CHEMICAL JOURNAL OF CHINESE UNIVERSITIES-CHINESE
(2021)
Article
Chemistry, Multidisciplinary
Xiaojun Hu, Bingwei Zhou, Hongwei Jin, Yunkui Liu, Liming Zhang
CHEMICAL COMMUNICATIONS
(2020)
