Article
Chemistry, Organic
Sebastian Fischer, Terrence-Thang H. Nguyen, Andreas Ratzenboeck, Huw M. L. Davies, Oliver Reiser
Summary: A stereoselective, solvent- and metal-free method for endocyclic C-C bond cleavage of monocyclopropanated cyclopentadienes mediated by strong acids has been developed. It leads to the formation of highly functionalized six-membered carbocycles with high stereocontrol. The critical step involves the formation of a cyclopropyl carbocation that undergoes endocyclic ring opening through an SN2'-type attack of various nucleophiles. Subsequent synthetic transformations demonstrate the versatility of the resulting cyclohexenes for the synthesis of compounds with nonconventional substitution patterns.
Article
Chemistry, Multidisciplinary
Hiroki Tashiro, Masahiro Terada, Itaru Nakamura
Summary: Gold-catalyzed reactions were used to synthesize 2H-azirines with sulfenyl and acyl groups at the 3-position, yielding good to excellent results. These reactions involved internal transfer of sulfinyl oxygen atom and carbene insertion into the N-S bond for ring construction.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
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, Multidisciplinary
Martin Piesch, Stephan Reichl, Michael Seidl, Gabor Balazs, Manfred Scheer
Summary: A synthetic pathway was developed for the synthesis of novel anionic sandwich complexes with cyclo-E-3 (E=P, As) ligands, which were further utilized to obtain various types of complexes. The reaction pathway was elucidated using DFT calculations, leading to the successful isolation of heteroatomic complexes with unique structures.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Vladyslav Smyrnov, Jerome Waser
Summary: An electrophile-induced semipinacol rearrangement of cyclopropenylcarbinols is described, enabling the synthesis of polyfunctionalized cyclopropanes under mild metal-free conditions. The reaction demonstrates broad scope, accommodating various electrophiles, migrating groups, and substitution patterns on the cyclopropene. It is particularly useful for the synthesis of small ring-containing spirocycles, which are important building blocks in medicinal chemistry.
Article
Chemistry, Organic
Figueroa-Valverde Lauro, Diaz Cedillo Francisco, Rosas-Nexticapa Marcela, Lopez-Ramos Maria, Mateu-Armand Virginia, Garcimarero-Espino E. Alejandra, Ortiz-Ake Yazmin
Summary: The study aimed to synthesize two oxacan derivatives with moderate yielding using reagents that are not expensive and do not require special conditions.
JOURNAL OF HETEROCYCLIC CHEMISTRY
(2021)
Article
Chemistry, Organic
Raquel Perez-Guevara, Luis A. A. Sarandeses, M. Montserrat Martinez, Jose Perez Sestelo
Summary: A novel indium-catalyzed synthesis of benzannulated spiroketals is reported in this study. The reaction proceeds under mild conditions using a low catalyst loading of indium triiodide, and produces a series of benzannulated spiroketals in good yields. The method involves indium(iii)-catalyzed electrophilic alkyne activation followed by regioselective intramolecular hydroalkoxylation reaction, representing an economical alternative to precious transition metals and providing a complementary strategy for the selective synthesis of spiroketals.
ORGANIC CHEMISTRY FRONTIERS
(2022)
Article
Chemistry, Applied
Chih-Wei Hsu, Yen-Ting Lu, Chi-Ping Lin, Woo-Jin Yoo
Summary: A synthetic strategy involving Simmons-Smith cyclopropanation and acid-catalyzed pinacol rearrangement was developed to transform α-hydroxy silyl enol ethers into 1-substituted bicyclo[2.1.1]hexan-5-ones. These bicyclic ketones underwent further synthetic manipulations to generate various 1,5-disubstituted bicyclo[2.1.1]hexanes, which could serve as potential bioisosteres of ortho-substituted arenes.
ADVANCED SYNTHESIS & CATALYSIS
(2023)
Article
Chemistry, Organic
Margherita Zanini, Andrea Cataffo, Antonio M. Echavarren
Summary: A method for the synthesis of cyclobutanones through gold(I)-catalyzed [2 + 2] cycloaddition of ynol ethers with alkenes has been developed. Additionally, it was found that internal aryl ynol ethers can undergo (4 + 2) cycloaddition reaction with alkenes leading to the corresponding chromanes.
Article
Chemistry, Multidisciplinary
Tushar Singha, Ganesh Arjun Kadam, Durga Prasad Hari
Summary: The Dowd-Beckwith reaction is a powerful method for synthesizing medium to large-sized carbocyclic scaffolds by ring-expansion of carbonyl compounds via alkoxy radicals. However, its synthetic applications are hampered by the dominating pathway of Dowd-Beckwith ring-expansion followed by H-atom abstraction, and there is currently no report on the functionalization of ring-expanded radicals using non-carbon based nucleophilic reagents.
Article
Chemistry, Multidisciplinary
Gorka Garay, Josebe Hurtado, Manuel Pedron, Lorena Garcia, Efraim Reyes, Eduardo Sanchez-Diez, Tomas Tejero, Luisa Carrillo, Pedro Merino, Jose L. Vicario
Summary: We have demonstrated the catalytic and enantioselective rearrangement of vinylcyclopropane-cyclopentene, using (vinylcyclopropyl)acetaldehydes as starting materials and enamine intermediates for activation. The reaction involves the generation of a donor-acceptor cyclopropane, leading to the formation of an acyclic iminium ion/dienolate intermediate where stereochemistry is erased. The final cyclization step results in the stereocontrolled formation of various structurally distinct cyclopentenes.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Multidisciplinary
Frederik Kramm, Franziska Ullwer, Benedict Klinnert, Min Zheng, Bernd Plietker
Summary: We present an unusual cyclopropyl enyne cycloisomerization that activates C-C bonds in cyclopropanes, leading to the synthesis of substituted non-canonical tricyclic cyclobutanes with high stereocontrol using [(Ph3P)(2)Fe(CO)(NO)]BF4 as catalyst.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Chemistry, Multidisciplinary
Monika M. Lindner, M. Wasim Alachraf, Benjamin Mitschke, Philipp Schulze, Markus Leutzsch, Benjamin List
Summary: A method for converting aldehydes into arenes is designed, involving the reaction of aldehydes to form fulvenes, followed by photochemical and platinum-catalyzed rearrangements into Dewar benzene derivatives, which finally isomerize into the desired arenes. Computational studies support the feasibility of this route, but fulvene irradiation unexpectedly results in isomerization into spiro[2.4]heptadienes. The mechanistic investigation of this unusual photorearrangement provides access to various spiro[2.4]heptadienes with different substituents.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Chemistry, Organic
Ryota Ogura, Kazuto Satoh, Wataru Kiuchi, Kosuke Kato, Kazutada Ikeuchi, Takahiro Suzuki, Keiji Tanino
Summary: A two-step synthesis of geminal divinyl compounds from ketones was developed. An allyl titanium reagent reacted with a ketone to form a tertiary alcohol, which was then subjected to a rearrangement reaction mediated by a Bronsted acid to generate a geminal divinyl compound. Introduction of another alkene moiety followed by ring closing metathesis resulted in a bicyclic compound possessing a vinyl group at the bridgehead position.
Article
Chemistry, Multidisciplinary
Shengbiao Yang, Chunyang Liu, Xiaoyan Shangguan, Yan Li, Qian Zhang
Summary: An unprecedented copper-catalyzed four-component reaction has been developed for the efficient synthesis of a wide range of imide derivatives.
Article
Chemistry, Applied
Dario Allegue, Jairo Gonzalez, Sergio Fernandez, Javier Santamaria, Alfredo Ballesteros
ADVANCED SYNTHESIS & CATALYSIS
(2019)
Review
Chemistry, Multidisciplinary
Ruben Vicente
Summary: This review summarizes key reactivities relying on C-C bond cleavages of cyclopropenes, including both metal-catalyzed and metal-free transformations. The emphasis is on the synthetic utility and mechanistic aspects of various methodologies discussed, covering a range of reactions involving vinyl carbenes, metathesis processes, heterocycles syntheses, SEAr reactions, metalation-ring opening sequences, and cycloadditions. The focus is on results from 2007 to 2019, with relevant pioneering transformations eventually included.
Article
Chemistry, Organic
Sergio Fernandez, Javier Santamaria, Alfredo Ballesteros
Article
Chemistry, Multidisciplinary
Tatiana Suarez-Rodriguez, Angel L. Suarez-Sobrino, Alfredo Ballesteros
Summary: Gold(I)-catalyzed higher-order [8+2] cycloadditions of 8-aryl-8-azaheptafulvenes with allenamides and ynamides were studied, resulting in the formation of 1,8-dihydrocycloheptapyrroles and 2-amido-1,4-dihydrocycloheptapyrroles, respectively. The reactions proceeded with good yields and various substituents, suggesting a nucleophilic attack mechanism involving the gold-activated electron-rich moieties of the allenamide and ynamide.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Applied
Dario Allegue, Javier Santamaria, Alfredo Ballesteros
Summary: In this study, a gold(I)-catalyzed and atom-economical synthesis of ortho-N-indolyl-N-pyrazolylbenzene from 1,2,3-triazapentalenes and ynamides was reported. The reaction involves the cleavage of the triazole ring, formation of an alpha-imino gold carbene intermediate, and an aza-Nazarov-type cyclization with participation of an arene ring. The formal [4+1] heterocycloaddition reaction provides the four-carbon synthon from the ynamide, and indole synthesis can also be achieved in a one-pot procedure from their 1-propargyl-1H-benzotrizaole precursors.
ADVANCED SYNTHESIS & CATALYSIS
(2021)
Article
Chemistry, Applied
Sergio Fernandez, Javier Santamaria, Alfredo Ballesteros
Summary: This study presents a simple, regioselective and high yielding gold-catalyzed synthesis of benzofulvenes using progargylsilanes and benzophenones as reactants. The silyl moiety synergistically activates the carbonyl compound, and the participation of aluminum trichloride as a cocatalyst clearly increases the gold catalytic activity in the cyclization step. Mechanistic intermediates, including enynes and silylbenzofulvenes, have been isolated, and control experiments confirm the involvement of [LAu][NTf2AlCl3] complex as the true catalyst. The coordination of the Lewis acid to the gold counterion dramatically enhances the gold activity.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Organic
Belen Rubial, Alfredo Ballesteros, Jose M. Gonzalez
Summary: The addition of catalytic amounts of bistriflimide triggers useful coupling reactions between benzyl acetates and trimethyl(alkynyl)silanes as well as trimethyl(alkoxy)silanes, resulting in the formation of propargyl arenes and benzyl alkyl ethers, respectively. The added acid facilitates the release of reactive trimethylsilylium ion into the reaction media, which acts as the ultimate catalytic species responsible for the formation of C-C and C-O bonds. The cationic nature of these coupling processes is confirmed.
EUROPEAN JOURNAL OF ORGANIC CHEMISTRY
(2022)
Review
Chemistry, Medicinal
Alba Fombona-Pascual, Javier Fombona, Ruben Vicente
Summary: This research analyzes the development and potential of augmented reality technology in the field of chemistry for three-dimensional molecule visualization. The study finds that there are already some successful examples of augmented reality applications in education and research environments, although traditional two-dimensional screen visualization is still more commonly used for teaching.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2022)
Article
Chemistry, Applied
Sergio Fernandez, Dario Allegue, Javier Santamaria, Alfredo Ballesteros
Summary: A gold-catalyzed bispropargylation reaction of xanthone derivatives is described. The use of propargylsilanes allows for a deoxygenative bispropargylation through the catalytic addition of the allenylgold intermediate to the activated carbonyl moiety. This reaction shows diastereoselectivity with both xanthone and thioxanthone derivatives.
ADVANCED SYNTHESIS & CATALYSIS
(2022)
Article
Chemistry, Multidisciplinary
Dario Coto, Iratxe Barbolla, Ruben Vicente
Summary: Silylcyclopropenes as precursors of alpha-silyl vinyl carbenes can undergo reactions with alkenes, leading to the synthesis of cyclopropylsilanes and cis-1,2-disubstituted cyclopropanes with high selectivity.
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Ruben Vicente, Eva Tudela, Miguel A. Rodriguez, Angel L. Suarez-Sobrino, Alfredo Ballesteros
Summary: The synthesis of specific cyclopropane-tethered 1,5-enynes, known as 6-alkynyl-4-alkylidenebicyclo[3.1.0]hex-2-enes, led to the discovery of an unprecedented gold-catalyzed rearrangement to indenes. A computational study of the mechanism behind this significant skeleton rearrangement is also presented.
CHEMICAL COMMUNICATIONS
(2022)
Review
Chemistry, Inorganic & Nuclear
Nicola Panza, Giorgio Tseberlidis, Alessandro Caselli, Ruben Vicente
Summary: This article presents an overview of the recent developments in pyridine-containing 12-membered tetraazamacrocycles with pyclen or Py2N2 backbones and their metal complexes from 2017 to the present. It includes the syntheses of newly described ligands and complexes relevant to medicine, as well as the reactivity of complexes bearing these ligands and their applications in catalysis.
DALTON TRANSACTIONS
(2022)
Article
Chemistry, Multidisciplinary
Rafael Barbas, Merce Font-Bardia, Alfredo Ballesteros, Gemma Arsequell, Rafel Prohens, Antonio Frontera
Summary: This study conducted a combined computational and crystallographic analysis of iododiflunisal, revealing static discrete disorder in the solid state and the formation of typical R2(2)(8) centrosymmetric dimers. Additionally, the presence of iodine facilitated the formation of halogen bonds and halogen-halogen contacts, as observed in the crystal packing.
Article
Chemistry, Analytical
Jesus Nicolas Carcelen, Juan Manuel Marchante-Gayon, Pablo Rodriguez-Gonzalez, Alfredo Ballesteros, Jose M. Gonzalez, Jose Angel Cocho de Juan, Jose Ignacio Garcia Alonso
Summary: We developed an analytical method for the determination of MIT and DIT in newborn urine and dried urine spots (DUS). The method can correct for possible interconversions between MIT and DIT during sample preparation and provide accurate results. MIT was detected in samples from healthy newborns.
