Article
Chemistry, Multidisciplinary
Teng Yuan, Kelton Radefeld, Chuan Shan, Carter Wegner, Erin Nichols, Xiaohan Ye, Qi Tang, Lukasz Wojtas, Xiaodong Shi
Summary: Here, we have reported an intermolecular asymmetric hydrative aldol reaction by using a vinyl-gold intermediate under ambient conditions. This reaction provides a base-free approach to β-hydroxy amides with high efficiency, yielding up to 95% and with over 50 examples. The use of vinyl gold intermediate as a reactive nucleophile and Fe(acac)(3) as a critical co-catalyst prevents undesired protodeauration, allowing the transformation to proceed under mild conditions with excellent functional group tolerance and stereoselectivity (>20:1 d.r. and up to 99% ee).
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Wen-Cheng Li, Lei Yang, Zhong-Lin Wei, Wei-Wei Liao
Summary: A straightforward diastereo- and enantioselective Claisen rearrangement/oxa-Michael addition tandem sequence with a cinchona squaramide catalyst was developed for the synthesis of valuable dihydropyrans. The organo-bifunctional catalyst played a crucial role in enhancing the stereoselectivity in this asymmetric tandem sequence. Additionally, good yields and moderate stereoselectivities were achieved in the asymmetric catalytic sequential processes of hydroalkoxylation/Claisen rearrangement/cyclization and Claisen rearrangement/aza-Michael addition tandem sequences.
Article
Chemistry, Multidisciplinary
Marta Solas, Samuel Suarez-Pantiga, Roberto Sanz
Summary: This study describes the asymmetric synthesis of cyclopentachromenones from gold-catalyzed reaction of readily available skipped alkenynones. The cascade reaction involves an initial anti-Michael hydroarylation and a subsequent Nazarov cyclization. Excellent enantiomeric ratios and chemical yields are achieved under mild reaction conditions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Li-Ping Tan, Dong Liang, Ying Cheng, Wen-Jing Xiao, Jia-Rong Chen
Summary: A visible-light-induced photoredox-catalyzed tandem radical addition/cyclization of 2-alkenylphenols and CBr4 has been developed, providing efficient access to various 4-arylcoumarins in a one-pot fashion. Preliminary mechanistic investigations suggest a radical process and the significant role of water as an additive.
ORGANIC CHEMISTRY FRONTIERS
(2021)
Article
Chemistry, Organic
Yunliang Yu, Nazarii Sabat, Meriem Daghmoum, Zhenhao Zhang, Pascal Retailleau, Gilles Frison, Angela Marinetti, Xavier Guinchard
Summary: Enantioselective tandem cycloisomerization/addition reactions of 2-alkynyl enones with 1- and 2-naphthols were investigated using gold(I) catalysts featuring hybrid phosphine-phosphoric acid chiral ligands, based on the tethered counterion-directed catalysis strategy. The reactions proceeded at low catalyst loading (0.2-1 mol%) without the need for silver additives, and the naphthols acted as both O- and C-nucleophiles, resulting in the formation of addition products with high enantioselectivity. The mechanism of these reactions was elucidated by DFT calculations.
ORGANIC CHEMISTRY FRONTIERS
(2023)
Article
Chemistry, Applied
Brigita Mudrakova, Peter Kisszekelyi, Denisa Vargova, Dorota Zakiewicz, Radovan Sebesta
Summary: This paper presents a highly enantio- and diastereoselective tandem transformation method, using Cu-catalyzed conjugate addition of Grignard reagents to heterocyclic Michael acceptors, followed by one-pot trapping of in situ formed enolates with stabilized carbocations or their equivalents. This method allows the installation of structurally attractive substituents on heterocyclic compounds.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
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.
Review
Chemistry, Organic
Peter Kisszekelyi, Radovan Sebesta
Summary: Metal enolates are indispensable intermediates and building blocks in many organic synthetic transformations. This review focuses on chiral metal enolates obtained by asymmetric conjugate additions of organometallic reagents, which are complex intermediates that can be employed in various transformations. The review also highlights the efforts to expand the reactivity of metal enolates with new electrophiles and provides information on their applications in total synthesis.
BEILSTEIN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jun-Jie Tian, Rui-Rui Li, Gui-Xiu Tian, Xiao-Chen Wang
Summary: Here, we describe a new method for enantioselective C-H allylation of pyridines at C3 using a tandem borane and palladium catalysis. This method involves borane-catalyzed pyridine hydroboration, palladium-catalyzed enantioselective allylation of the resulting dihydropyridines with allylic esters, and air oxidation to afford the products. This method allows for the introduction of an allylic group at C3 with excellent regio- and enantioselectivities.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Zhenqiang Chen, Yingying Sun, Shoufeng Wang, Qing-Wei Zhang
Summary: A base-promoted tandem Michael addition of malonates to 2,3-bis(diarylphosphinyl)-1,3-butadienes was developed for the synthesis of cyclopentyl 1,2-bisphosphine compounds. This method enables rapid construction of various 1,2-bis(diarylphosphinyl)cyclopentanes, and features readily accessible reactants, mild conditions and good functional group tolerance. The product could be easily transformed to the corresponding transition metal complexes, which may find broad applications in asymmetric catalysis.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jia-Hao Xie, Yi-Ming Hou, Zuolijun Feng, Shu-Li You
Summary: Here, we describe a synthesis method for cyclohexanones with multiple continuous stereocenters by combining copper-catalyzed asymmetric conjugate addition of dialkylzinc reagents to cyclic enones with iridium-catalyzed asymmetric allylic substitution reaction. The reaction yields good to excellent results in terms of yield, diastereoselectivity, and enantioselectivity. Unlike previous studies focusing on adjacent stereocenter construction (1,2-position), this reaction achieves stereodivergent construction of nonadjacent stereocenters (1,3-position) by utilizing two chiral catalysts with different enantiomers.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Daniel Rozsar, Alistair J. M. Farley, Iain McLauchlan, Benjamin D. A. Shennan, Ken Yamazaki, Darren J. Dixon
Summary: This article describes the enantioselective intermolecular conjugate addition of nitroalkanes to unactivated alpha,beta-unsaturated esters catalyzed by a bifunctional iminophosphorane (BIMP) superbase. It provides a straightforward approach to the synthesis of pharmaceutically relevant enantioenriched gamma-nitroesters with unprecedented selectivity. The methodology demonstrates broad substrate scope and has been successfully applied on a gram scale with reduced catalyst loading, allowing for catalyst recovery.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Review
Chemistry, Organic
Cui Xiaoyuan, Zhou Feng, Wu Haihong, Zhou Jian
Summary: Cooperative catalysis is an effective strategy to improve the efficiency and selectivity of organic reactions. Combining chiral amines and gold(I) catalysts can achieve asymmetric tandem reactions, allowing the construction of complex chiral compounds.
CHINESE JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Hui Yang, Ru Zhang, Su-Zhen Zhang, Qing Gu, Shu-Li You
Summary: Researchers have developed a series of chiral spiro ligands (BCSCp) from commercially available and cheap Bisphenol C, and prepared their corresponding rhodium complexes. These complexes have been successfully applied in enantioselective aryl C-H addition to nitroalkenes, producing C-H adducts with yields up to 88% and ee up to 98%.
Article
Chemistry, Applied
Jyoti M. Honnanayakanavar, Purna Chandra Behera, Surisetti Suresh
Summary: This study discloses a copper-catalyzed tandem process that integrates N-arylation and 1,4-conjugate addition using cyclic enaminones and ortho-halochalcones as substrates, resulting in the formation of diverse tricyclic tetrahydroacridinone derivatives in moderate to excellent yields.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
