Article
Chemistry, Multidisciplinary
Shuang Yang, Jun-Yunzi Wu, Shuang Lin, Meicen Pu, Zhi-Shu Huang, Honggen Wang, Qingjiang Li
Summary: Divergent fluorination reactions of vinylcyclopropanes with different electrophiles are reported, allowing the facile synthesis of homoallylic monofluorides and vicinal-difluorides through ring-opening 1,5-hydrofluorination and ring-retaining 1,2-difluorination, respectively. Both protocols have mild conditions, simple operations, good functional group tolerance, and generally good yields. The practicality of these reactions is demonstrated by their scalability and the successful conversion of the formed homoallylic monofluorides into other complex fluorinated molecules.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Organic
Yiding Wang, Lei Shen, Helin Wang, Yixin Luo, Qingle Zeng
Summary: The ring-opening addition reaction of activated vinyl cyclopropanes with N-tosylhydrazones in the presence of palladium(0) and triphenylphosphine yields N-tosylhydrazone butenylmalonate compounds. Aromatic aldehyde-derived N-tosylhydrazones produce both terminal and internal N-allylated products, with the terminal products being the major ones. On the other hand, ketone-derived tosylhydrazones only yield terminal addition products. The transformation relationship between the terminal and internal N-allylated products is also observed. A reasonable mechanism based on preliminary experimental results is proposed.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Physical
Amit Singh Adhikari, Soumen Pandit, Ruchir Kant, Nilanjana Majumdar
Summary: An efficient method for highly selective allylic substitution of vinylcyclopropanes using carboxylic acids via iridium catalysis has been developed, providing a high yield of synthetically useful chiral building blocks. The practical application of the products in useful transformations demonstrates its utility.
Article
Chemistry, Multidisciplinary
Felipe Verdugo, Ricardo Rodino, Martin Calvelo, Jose Luis Mascarenas, Fernando Lopez
Summary: The reactivity of carbonyl-tethered alkylidenecyclopropanes (ACPs) can be directed towards tandem cycloisomerization/cross-coupling processes by using Pd-0 catalysts with phosphorus-based monodentate ligands. This allows for the synthesis of a wide variety of highly functionalized cyclic alcohols and amines through the formation of key pi-allyl oxapalladacyclic intermediates which are trapped with external nucleophilic partners.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Organic
Jiaan Shao, Ke Shu, Shuangrong Liu, Huajian Zhu, Jiankang Zhang, Chong Zhang, Ling-Hui Zeng, Wenteng Chen
Summary: A palladium-catalyzed ring-opening reaction of 2H-azirines with hydrazones has been developed, providing an alternative route for the construction of various polysubstituted pyrazoles with a wide substrate scope. A plausible mechanism is proposed for this reaction, enriching the chemical conversion of 2H-azirines.
Article
Chemistry, Physical
Abdoul G. Diallo, Deborah Paris, Djiby Faye, Sylvain Gaillard, Mark Lautens, Jean-Luc Renaud
Summary: This study reports a general approach for the allylation of oxa- and azabenzonorbornadienes by merging organophotoredox and nickel catalysis. The method allows for selective allylation of various heterocyclic alkene derivatives with a broader range of allylic acetate compounds. Notably, the reaction does not require air-sensitive organometallic species or metal reductants.
Article
Chemistry, Multidisciplinary
Dong Wu, Hailiang Pang, Guoyin Yin
Summary: In this study, a highly 1,1-regioselective alkenylboration reaction of styrenes was achieved by using alkenyl triflates and a diboron reagent as the coupling partners. The reaction showed high synthetic reactivity for a wide range of styrene derivatives and alkenyl triflates. The success of this reaction was attributed to the application of a 1,10-phenanthroline-derived ligand and the addition of ammonium chloride salt. Additionally, acrylate esters could also selectively afford the 1,1-alkenylboration products under the same reaction conditions.
CHINESE CHEMICAL LETTERS
(2023)
Article
Chemistry, Applied
Patricia Garcia-Martinez, Olaya Bernardo, Javier Borge, Javier Gonzalez, Luis A. Lopez
Summary: The BF3 & sdot;OEt2-catalyzed reaction of azulene with N-protected aziridines provides a general and efficient method for synthesizing phenethylamine-azulene conjugates with high regioselectivity (up to 91% yield). Stereochemical studies and DFT calculations confirm a concerted SN2-type mechanism for the ring-opening reaction of aziridine.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Applied
Rene Hommelsheim, Robin van Nahl, Lena M. Hanek, Jas S. Ward, Kari Rissanen, Carsten Bolm
Summary: This study reports a palladium-catalyzed domino reaction that enables the synthesis of 3-amino-substituted 1,2,4-benzothiadiazine 1,1-dioxides at room temperature. The method demonstrates good substrate compatibility and mild reaction conditions.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Multidisciplinary
Boon Beng Tan, Ming Hu, Shaozhong Ge
Summary: A ligand-controlled cobalt-catalyzed ring-opening dihydroboration method is developed to access versatile skipped diboronates. Various arylidenecyclopropanes reacted with pinacolborane to yield 1,3- or 1,4-diboronate products with high regioselectivity. The resulting diboronates can undergo various transformations, enabling selective installation of different functional groups on alkyl chains.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Oliver R. Gedde, Andreas Bonde, Peter Golbaekdal, Troels Skrydstrup
Summary: An expedient method for the ex-situ generation of difluoroiodomethane (DFIM) and its immediate use in a Pd-catalyzed difluoromethylation reaction is reported. The method involves heating a solution of bromodifluoroacetic acid with sodium iodide in sulfolane to generate near stoichiometric amounts of DFIM, which is then used for the subsequent catalytic coupling step. The method allows for the installation of fluorine-containing C-1 groups onto pharmaceutically relevant molecules and is adaptable for deuterium incorporation by adding D2O to the DFIM-generating chamber.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Jun-An Xiao, Huan Zhang, Xue-Ling Luo, Ru-Fang Meng, Wei Wang, Wei-dong Lu, Wei Su, Chenxiang Lin, Peng-Ju Xia, Hua Yang
Summary: A palladium-catalyzed ring-opening [3 + 2]-annulation reaction was developed for the synthesis of seven-membered benzosultams from spirovinylcyclopropanyloxindoles and cyclic N-sulfonylimines. The reaction yielded a wide range of compounds with both a quaternary center and axially chiral biaryl scaffolds, with an average yield of 87% and moderate to excellent diastereoselectivities. Enantioenriched benzosultams were also successfully synthesized in good yields with excellent atropoenantioselectivities using the Pd-2(dba)(3)/(S,S,S)-SKP ligand. The practical utility of this method was demonstrated through gram-scale reactions and diversified synthetic transformations.
Article
Chemistry, Multidisciplinary
Maosheng Li, Shuai Zhang, Xiaoyong Zhang, Yanchao Wang, Jinlong Chen, Youhua Tao, Xianhong Wang
Summary: The study describes an effective unimolecular anion-binding organocatalysis for ring-opening polymerization of O-carboxyanhydrides (OCAs), achieving the synthesis of highly isotactic poly(phenyllactic acid) (Ph-PLA) through a dynamic cooperative anion-binding mechanism. This approach addresses the challenge of synthesizing high molecular weight stereoregular polyesters by facilitating efficient chain propagation and maintaining high selectivity for OCA ring-opening over side reactions.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Applied
Andrei Baran, Mariia Babkova, Jana Petkus, Kirill Shubin
Summary: A convenient and general method for Suzuki-Miyaura double cross-coupling of various dibromothiophenes was developed. Using a simple and cheap catalytic system, diarylthiophenes, useful in the synthesis of metal-organic frameworks (MOFs), can be obtained in moderate to excellent yields. The efficiency of the catalytic process and excess of boronic acids help to suppress side products and simplify the purification of products.
APPLIED ORGANOMETALLIC CHEMISTRY
(2022)
Article
Materials Science, Multidisciplinary
Thierry K. Slot, Varun Natu, Enrique Ramos-Fernandez, Antonio Sepulveda-Escribano, Michel Barsoum, Gadi Rothenberg, N. Raveendran Shiju
Summary: MXenes are a new family of two-dimensional carbides and/or nitrides with O, OH and/or F atoms terminating their 2D surfaces. Ti3C2Tx, the most studied compound of the MXene family, is demonstrated to be a good acid catalyst for various reactions, with the catalytic activity and selectivity being influenced by surface modifications. A thin oxide layer on the Ti3C2Tx surface is essential for catalyzing ring-opening reactions.
Article
Chemistry, Organic
Kaveh Farshadfar, Melissa J. Bird, Wesley J. Olivier, Christopher J. T. Hyland, Jason A. Smith, Alireza Ariafard
Summary: The study demonstrates that iodosobenzene can serve as a convenient and controlled precursor of the oxidant hypobromite under the right conditions. Water acts as a cocatalyst in the generation of hypobromite, which is shown to be a more powerful oxidant than iodosobenzene in alcohol oxidation. The findings provide a clear rationale for the experimental observations on the effectiveness of halide additives in the oxidation process.
JOURNAL OF ORGANIC CHEMISTRY
(2021)
Article
Chemistry, Physical
Mona Jalali, Christopher J. T. Hyland, Alex C. Bissember, Brian F. Yates, Alireza Ariafard
Summary: Density functional theory calculations were used to investigate the mechanisms of hydroalkylation reactions of styrenes with 1,3-diketones using AuCl3/AgOTf or AgOTf catalyst systems. The study revealed that the reaction with AuCl3/AgOTf is initiated by the generation of highly electrophilic Au(OTf)(3), while the reaction with AgOTf catalyst proceeds via a demetallation process directly mediated by the silver catalyst. The electron deficiency of the metal center dictates the mechanistic scenarios that occur in these reactions.
Article
Chemistry, Multidisciplinary
Rasool Babaahmadi, Ayan Dasgupta, Christopher J. T. Hyland, Brian F. Yates, Rebecca L. Melen, Alireza Ariafard
Summary: Diazo compounds are commonly used as carbene precursors, and the ease of carbene generation depends on the substituents on either side of the diazo functionality. Tris(pentafluorophenyl)borane has been identified as a potential catalyst for carbene transfer reactions. This study reveals that the efficiency of the catalyst is directly influenced by the substituents on the aryl ring and the carbonyl group of the substrate, which allows for intelligent design of similar catalytic reactions.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Liam M. Joyce, Melanie A. Drew, Andrew J. Tague, Thanaphat Thaima, Ali Gouranourimi, Alireza Ariafard, Stephen G. Pyne, Christopher J. T. Hyland
Summary: The thermally induced cycloisomerization reactions of 1,6-allenynes were studied, resulting in the formation of alpha-methylene-gamma-lactams through intramolecular Alder-ene reactions. Computational and deuterium labelling studies provided evidence for the proposed mechanism, and a divergent mechanism distinct from the previous [2+2] cycloisomerization pathway was discovered.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Organic
Richmond Lee, Chi Bong Eric Chao, Xu Ban, Siu Min Tan, Haibo Yu, Christopher J. T. Hyland, Choon-Hong Tan
Summary: Density functional theory (DFT) was used to predict the mechanism for constructing congested quaternary-quaternary carbon(sp(3))-carbon(sp(3)) bonds in a pentanidium-catalyzed substitution reaction. Computational mechanistic studies revealed that sterically congested substrates prefer the S(N)2X manifold over S(N)2, and different halides as leaving groups showed reactivity in the order of I > Br > Cl > F. The catalyst screening suggested that pentanidium is still the choice for S(N)2X C-C bond formation.
JOURNAL OF ORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Kaveh Farshadfar, Andrew J. Tague, Mohammad Talebi, Brain F. Yates, Christopher J. T. Hyland, Alireza Ariafard
Summary: This study utilizes DFT calculations to uncover a mechanism called redox-promoted Bronsted acid activation, which elucidates the mechanistic details of the phenol and cyclohexadiene annulation catalyzed by the AuCl3/AgOTf mixed system. HOTf is identified as the active catalyst in the annulation reactions, produced in situ through the irreversible reduction of gold(III) to gold(I).
Article
Chemistry, Organic
Liam M. Joyce, Stephen A. Moggach, Christopher J. T. Hyland, Stephen G. Pyne, Scott G. Stewart
Summary: A nickel-catalyzed tetradehydro-Diels-Alder reaction of (E)-3-ene-1,8-diynes has been developed for the synthesis of isoindolines, dihydroisobenzofurans, and tetrahydroisoquinolines. Air-stable nickel catalysts, including novel nickel(0)-phosphite catalysts, were employed in this study. Additionally, the mechanism of trapping nickellacycle intermediates with pinacolborane to yield vinyl boronates was discussed to gain insights into the initial cycloisomerization process.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Organic
Lillian A. de Ceuninck van Capelle, Steven M. M. Wales, James M. M. Macdonald, Megan Kruger, Christopher Richardson, Michael G. G. Gardiner, Christopher J. T. Hyland
Summary: In this study, bench-stable benzoazepine-fused isoindoles were synthesized via oxidation from isoindoline precursors. The stereochemistry and conformational folding were examined using isoindoles 5d-f as models. The factors contributing to the stability of atropisomers were elucidated using various techniques including chiral UHPLC, X-ray crystallography, H-1 NMR spectroscopy, and DFT calculations, revealing the role of steric hindrance and folded conformation in stabilizing the system.
JOURNAL OF ORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Philip J. Chevis, Chi Bong Eric Chao, Christopher Richardson, Christopher Hyland, Richmond Lee, Stephen G. Pyne
Summary: The crotylation reactions of chiral α-F, α-OBz and α-OH aldehydes were carried out under Petasis-borono-Mannich conditions using (E)- or (Z)-crotylboronates and primary amines. The reactions resulted in γ-addition products with high diastereoselectivity and enantioselectivity. The stereochemical outcomes of the reactions could be explained using transition state models and were supported by DFT calculations. Representative products were transformed into highly functionalized 1,2,3,6-tetrahydropyridines and 3H-oxazolo[3,4-a]pyridine-3-ones, which are valuable scaffolds in synthesis.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Andrew J. Tague, Quoc Hoang Pham, Christopher Richardson, Stephen G. Pyne, Christopher J. T. Hyland
Summary: A formal palladium-catalyzed decarboxylative (4+2) cycloaddition reaction has been developed to produce highly valuable tetrahydroquinolines in moderate to excellent yields with high diastereoselectivity. The reaction protocol can tolerate a range of substituted 2-nitro-1,3-enynes, which are an under-utilized class of dipolarophiles. The tetrahydroquinoline products obtained feature numerous pendant functionalities for further synthetic manipulations.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Chi Bong Eric Chao, Stephen G. Pyne, Christopher J. T. Hyland, Richmond Lee
Summary: Density functional theory has been used to elucidate the mechanistic details of arylative cyclization reactions with arylboronic acids. The modeling results are in agreement with experimental observations and explain the high diastereo- and enantioselectivity at high reaction temperature. Additionally, a novel mechanism for base-free organoboron transmetalation has been revealed.
CHEMISTRY-AN ASIAN JOURNAL
(2023)
Article
Chemistry, Multidisciplinary
Quoc Hoang Pham, Andrew J. Tague, Christopher Richardson, Michael G. Gardiner, Stephen G. Pyne, Christopher J. T. Hyland
Summary: A Pd-catalysed (3 + 2) cycloaddition reaction of bis(trifluoroethyl) 2-vinyl-cyclopropane-1,1-dicarboxylate (VCP) with cyclic sulfamidate imine-derived 1-azadienes (SDAs) has been developed, leading to highly functionalized spiroheterocycles with three contiguous stereocentres, including a tetrasubstituted carbon bearing an oxygen functionality. The geminal trifluoroethyl ester groups can be selectively manipulated to afford spirocycles with four contiguous stereocentres. Additionally, reduction of the imine moiety can introduce a fourth stereocentre and expose a 1,2-amino alcohol functionality.
Article
Chemistry, Multidisciplinary
Quoc Hoang Pham, Andrew J. Tague, Christopher Richardson, Christopher J. T. Hyland, Stephen G. Pyne
Summary: The Pd-catalysed asymmetric allylic alkylation of prochiral enamide anions derived from 5H-oxathiazole 2,2-dioxides has been developed, leading to the synthesis of high-value allylated heterocyclic products with high regioselectivity and generally high enantioselectivity. The conversion between N- and C-allyl products was observed, with N-allylated products eventually converting to C-allylated products over time.
Review
Chemistry, Multidisciplinary
Deyao Li, Wenqing Zang, Melissa J. Bird, Christopher J. T. Hyland, Min Shi
Summary: The past decade has been a golden age for homogeneous gold-catalyzed reactions, transforming highly strained molecules into complex molecular architectures through unique electronic properties and catalytic abilities of gold catalysts. These catalysts have shown versatile reaction modes and deepened understanding with the development of various ligands. The evolution of gold catalysis has expanded its application into natural product synthesis and the potentiality of drug discovery, showcasing a magnificent renaissance for this ancient metal.
Review
Chemistry, Organic
Lillian A. de Ceuninck van Capelle, James M. Macdonald, Christopher J. T. Hyland
Summary: This review discusses the conformational and stereochemical properties of medium-ring benzo-fused N-heterocycles, highlighting the impact of different structural factors on the atropisomeric nature of these compounds. It serves as a valuable resource for the design, synthesis, and study of new and potentially bioactive compounds.
ORGANIC & BIOMOLECULAR CHEMISTRY
(2021)
