Article
Chemistry, Organic
Chittala Emmaniel Raju, Veerabhushanam Kadiyala, Gottam Sreenivasulu, Perla Bharath Kumar, Balasubramanian Sridhar, Galla Karunakar
Summary: Efficient gold-catalyzed formation of indenylidene-derived 1H-isochromene-4-carbaldehydes from substituted 1,5,10-triyne-O-silanes was achieved under mild reaction conditions. The reaction involved gold-catalyzed selective oxidation, 1,2-migration, nucleophilic addition, and 5-endo-dig cyclization, leading to the synthesis of the desired products in moderate to very good yields via the formation of new C-C and C-O bonds in one pot.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
Article
Chemistry, Organic
Dina Scarpi, Francesco Bagni, Cristina Faggi, Asier Carral-Menoyo, Enrique Gomez-Bengoa, Ernesto G. Occhiato
Summary: Six- and seven-membered ring-fused, functionalized cyclopentadienes can be obtained in moderate to excellent yields through a cascade process involving various reactions. Depending on the treatment of the crude reaction mixtures, different types of cyclopentadienes can be obtained.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Organic
Yong Xu, Jiangtao Sun
Summary: This study describes the use of gold-catalyzed cascade cyclization and 1,3-difunctionalization of 2-(1-alkyny)-2-alken-1-ones with N,O-acetals, leading to the discovery of novel 1,3-oxyaminomethylation and 1,3-aminomethylamination. By varying reaction conditions, particularly the gold catalysts, these two distinct reaction pathways can be selectively controlled. Tandem cyclization and 1,4-oxyaminomethylation have also been achieved.
Article
Chemistry, Applied
Da-Ping Jin, Shi-Qi Cao, Fu Cheng, Ze-Sen Xue, Run-Ze Li, Yan-Lin Pu, Dao-Yong Zhu, Wen Bao, Xue-Tao Xu, Shao-Hua Wang
Summary: An Au(I)-catalyzed cascade reaction involving cyclization and semipinacol rearrangement of 1,6-enynes has been developed for the synthesis of spiro[4.5]decanes and 7-azaspiro[4.5]decanes. The use of JohnPhosAuCl/NaBARF catalyst led to the formation of functionalizable spirocyclic products with high diastereoselectivity ranging from 6.7:1 to > 20:1 dr. A plausible reaction mechanism has been proposed based on previous literature and experimental findings.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Chunxiang Pan, Gaowei Wang, Hengyuan Zhao, Jianxiao Ni, Ruifeng Fan, Yongyun Zhou, Yuanbin Zhu, Shiyuan Wu, Baomin Fan
Summary: An efficient stereoselective cobalt-catalyzed hydrovinylative cyclization of 1,6-enynes with chalcones to obtain functionalized pyrrolidines has been developed. The products were furnished in good yields with up to 93% ee. A plausible mechanism through which the transformation was initiated by cyclization of 1,6-enynes is proposed.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Applied
Ana Milian, Lucia Sanchez-Jimenez, Jaime Tostado, Juan J. Vaquero, Manuel A. Fernandez-Rodriguez, Patricia Garcia-Garcia
Summary: The total synthesis of Laetevirenol A, a natural product with antioxidant activity, has been achieved using a gold-catalyzed cycloisomerization reaction. The construction of the phenanthrene moiety in Laetevirenol A was realized through this key step, which was influenced by the nature of substituents. Laetevirenol A was obtained in 10 steps from commercially available substrates, with a 20% global yield.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Applied
Ana Milian, Patricia Garcia-Garcia, Juan J. Vaquero, Roberto Sanz, Manuel A. Fernandez-Rodriguez
Summary: Gold(I)-catalyzed reactions provide a direct route to phenanthrene-based polycycles using external or internal nucleophiles. Alcohols can be used to obtain functionalized dihydrophenanthrenes, while benzo[b]triphenylenes can be synthesized using o-methoxyvinyl-o'-alkynylbiaryls.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Applied
Jun-Sheng Wei, Zi-Yu Xu, Yin Wei, Min Shi
Summary: In this paper, a gold(I)-catalyzed cascade cyclization of N- or O-nucleophile tethered-vinylidenecyclopropanes (VDCPs) is reported, leading to the synthesis of pyrrole, furan, pyrrolidine, and piperidine skeletons in 30%-98% yields. The reaction pathways depend on the carbon chain length connecting the nucleophile and VDCPs, resulting in different products. By using α-amino VDCPs and α-hydroxyl VDCPs with a methylene group as the connection, intramolecular nucleophilic addition and aromatization occur, followed by ring-opening of the cyclopropane unit to produce substituted pyrroles and furans. Extending the chain length to three or four carbons enables the formation of pyrrolidines and piperidines with a cyclobutene moiety through ring expansion of the cyclopropane unit and gold carbene induced vinylogous nucleophilic addition.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Xianfu Shen, Tianfeng Peng, Fan Wang, Shumin Li, Xingfu Lei, Yunxiao, Wang, Feixiang Cheng, Teng Liu
Summary: This report presents the total synthesis of two bioactive HPI alkaloids, Flustramine B and Debromoflustramine B, achieved through a Cu-catalyzed cascade arylation-alkylation sequence as a key step. The overall yields of the compounds were 37.6% and 31.1% after 9 steps of synthesis.
Article
Chemistry, Applied
Ying-Chun He, Yan-Mei Yan, Zhen-Xing Ren, Yong-Zhao Wang, Qiang Yu, Jun Xiong, Meng-Liang Wang
Summary: An approach to 2,3-dihydrobenzo[f]isoindolones by a Ag-catalyzed Ugi 4CR/cascade radical cyclization sequence under mild conditions was developed. The method successfully achieved regioselective synthesis of 2,3-dihydrobenzo[f]isoindolones in high yields by forming two C-C bonds under air atmosphere in one-pot fashion.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Organic
Manuel Freis, Moritz Balkenhohl, David M. Fischer, Tony Georgiev, Roman C. Sarott, Erick M. Carreira
Summary: The cobalt-catalyzed aminocyclization of unsaturated N-acyl sulfonamides in the presence of oxygen was reported, leading to the formation of α- and d-lactam aldehydes. Enantiomerically enriched α- and d-lactam alcohols were obtained by using an optically active cobalt catalyst. The obtained α-lactam aldehydes and alcohols were further elaborated into useful building blocks.
Article
Chemistry, Organic
Manuel Freis, Moritz Balkenhohl, David M. Fischer, Tony Georgiev, Roman C. Sarott, Erick M. Carreira
Summary: This paper reports a cobalt-catalyzed aminocyclization of unsaturated N-acyl sulfonamides in the presence of oxygen, leading to α- and d-lactam aldehydes. Chiral cobalt catalysts were utilized to obtain enantiomerically enriched α- and d-lactam alcohols. The α-lactam aldehydes and alcohols obtained can be elaborated into useful building blocks.
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
Shuai Jiang, Wen-Bin Cao, Xiao-Ping Xu, Shun-Jun Ji
Summary: A Co-catalyzed cyclization reaction of isocyanides, azides, and amines was developed to access quinazoline derivatives, featuring high atom economy, mild reaction conditions, excellent yields, and a broad substrate scope. The cascade reaction involved the formation of three to four C-N bonds and one or two rings, producing versatile intermediates for further transformations. The cobalt catalyst used in the reaction was found to be isolatable and reusable.
Article
Chemistry, Multidisciplinary
Julian Baars, Isabelle Grimm, Dirk Blunk, Joerg-Martin Neudoerfl, Hans-Guenther Schmalz
Summary: A 12-step total synthesis of the natural product dysiherbol A was achieved, revealing the need for revision of the originally proposed structure and absolute configuration. The synthesis involved key steps including Cu-catalyzed addition/enolate-trapping, Au-catalyzed double cyclization, and late installation of the C5-bridgehead methyl group. Spectroscopic measurements confirmed the identity of the synthetic compound with the natural product but with an opposite molecular rotation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Review
Chemistry, Physical
Mauro Mato, Cristina Garcia-Morales, Antonio M. Echavarren
Article
Chemistry, Multidisciplinary
Mauro Mato, Antonio M. Echavarren
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2019)
Article
Chemistry, Multidisciplinary
Dagmar Scharnagel, Imma Escofet, Helena Armengol-Relats, M. Elena de Orbe, J. Nepomuk Korber, Antonio M. Echavarren
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2020)
Article
Chemistry, Multidisciplinary
Franco Della-Felice, Margherita Zanini, Xiaoming Jie, Eric Tan, Antonio M. Echavarren
Summary: The Rh-III-catalyzed allylic C-H alkynylation of non-activated terminal alkenes selectively leads to linear 1,4-enynes at room temperature. Additionally, the vinylic C-H alkynylation of alpha, beta- and beta, gamma- unsaturated amides gives conjugated Z-1,3-enynes and E-enediynes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Imma Escofet, Helena Armengol-Relats, Hanna Bruss, Maria Besora, Antonio M. Echavarren
CHEMISTRY-A EUROPEAN JOURNAL
(2020)
Article
Chemistry, Multidisciplinary
Inmaculada Martin-Torres, Gala Ogalla, Jin-Ming Yang, Antonia Rinaldi, Antonio M. Echavarren
Summary: Chiral gold(I)-cavitand complexes exhibit high enantioselectivity in the enantioselective alkoxycyclization of 1,6-enynes, which is significant for the synthesis of carbazole alkaloids. Furthermore, the cavity effect of the gold(I) complexes induces constrained conformations of enynes in the cycloisomerization of dienynes, leading to high stereoselectivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Multidisciplinary
Allegra Franchino, Alex Marti, Stefano Nejrotti, Antonio M. Echavarren
Summary: A library of gold(I) chloride complexes with phosphine ligands incorporating (thio)urea and squaramide H-bond donors was prepared to promote chloride abstraction from Au(I) via H-bonding. In the absence of silver additives, complexes bearing squaramides and trifluoromethylated aromatic ureas displayed good catalytic activity in various reactions, including cyclization and tandem reactions. Kinetic studies and DFT calculations suggest that the reaction's energy span is influenced by both the chloride abstraction step and subsequent cyclization step facilitated by the bidentate H-bond donor.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Review
Chemistry, Organic
Helena Armengol-Relats, Mauro Mato, Imma Escofet, Antonio M. Echavarren
Summary: The use of electrophilic gold(I) complexes to selectively activate certain types of substrates for generating versatile metal carbenes is a powerful tool for building complex molecular structures through formal cycloadditions or complex cascade reactions. The development of non-acceptor metal carbenes is challenging but can lead to diverse reactivity with different types of molecules.
SYNTHESIS-STUTTGART
(2021)
Article
Chemistry, Medicinal
Sofia Ferrer, Michael E. Muratore, Peter Buijnsters
Summary: USP30 inhibitors have emerged as potential alternative treatments for neurodegenerative disorders and other diseases associated with defective mitophagy. Research efforts have led to the discovery of potent and selective small-molecule inhibitors, some of which covalently bind to the target. However, complete pharmacological characterization and in vivo evaluation are still lacking. Target validation could pave the way for the development of USP30 inhibitors as marketed drugs.
EXPERT OPINION ON THERAPEUTIC PATENTS
(2022)
Article
Chemistry, Multidisciplinary
Allegra Franchino, Alex Marti, Antonio M. Echavarren
Summary: A new strategy for enantioselective transition-metal catalysis is presented, where precise positioning of chiral counteranions responsible for asymmetric induction is achieved by placing a H-bond donor on the ligand of a cationic complex. This paradigm was successfully implemented in 5-exo-dig and 6-endo-dig cyclizations of 1,6-enynes, allowing the use of chiral anions in Au(I)-catalyzed reactions of challenging alkyne substrates. Experimental evidence confirmed the crucial H-bonding interaction at the heart of the catalytic system.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Physical
Ulysse Caniparoli, Imma Escofet, Antonio M. Echavarren
Summary: Planar chiral monodentate 1,3-disubstituted ferrocene phosphines inspired by JohnPhos-type ligands have been synthesized and applied for the enantioselective gold(I) catalyzed [4 + 2] cycloaddition of 1,6-arylenynes. Computational studies elucidated the working mode of the catalyst, involving attractive noncovalent interactions that induce the folding of the substrate in the chiral environment of the ligand.
Article
Chemistry, Multidisciplinary
Andrea Cataffo, Miguel Pena-Lopez, Riccardo Pedrazzani, Antonio M. Echavarren
Summary: This study presents two classes of stereoselective cyclizations using a chiral auxiliary approach. The first class involves the stereoselective cascade cyclization of 1,5-enynes using Oppolzer camphorsultam as chiral auxiliary, leading to the synthesis of enantioenriched spirocyclic ketones. The second class focuses on the stereoselective alkoxycyclization of 1,6-enynes mediated by Evans-type oxazolidinone, resulting in the formation of enantioenriched beta-tetralones after removal of the auxiliary.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Physical
Alex Marti, Gala Ogalla, Antonio M. Echavarren
Summary: The enantioselective reaction of 1,6-enynes with O-, N-, and C-nucleophiles has been achieved through matched ion pair gold(I) catalysis. The chiral gold(I) cation and anion are H-bonded through a urea group, leading to very high levels of enantiocontrol (>99:1 er) for a wide range of substrates. DFT studies highlight the importance of the H-bond donor group in anchoring the matched chiral cation- and anion-favoring additional noncovalent interactions.
Article
Chemistry, Multidisciplinary
Eduardo Garcia-Padilla, Imma Escofet, Feliu Maseras, Antonio M. Echavarren
Summary: Through computational analysis, we have identified the dominant structures of the intermediates of gold(I)-catalyzed cyclizations of 1,5-enynes and 1,5-allenenes, including gold(I) cyclopropylcarbenes, endocyclic vinylgold complexes and previously unreported non-classical carbocationic minima. Cyclopropylcarbene structures are consistently favored as the most stable intermediates for all studied substitution patterns.
Article
Chemistry, Organic
Mauro Mato, Inmaculada Martin-Torres, Bart Herle, Antonio M. Echavarren
ORGANIC & BIOMOLECULAR CHEMISTRY
(2019)
