A5101511280- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Catalytic C–H Functionalization Methods
- Oxidative Organic Chemistry Reactions
- Synthesis and Catalytic Reactions
- Crystallography and molecular interactions
- Catalytic Cross-Coupling Reactions
- Asymmetric Hydrogenation and Catalysis
- Chemical synthesis and alkaloids
- Vanadium and Halogenation Chemistry
- Sulfur-Based Synthesis Techniques
- Alkaloids: synthesis and pharmacology
- Synthetic Organic Chemistry Methods
- Plant Parasitism and Resistance
- Retinoids in leukemia and cellular processes
- Catalytic Alkyne Reactions
- Plant and animal studies
- Plant Molecular Biology Research
- Radioactive element chemistry and processing
- Asymmetric Synthesis and Catalysis
- Radical Photochemical Reactions
- Chemical Synthesis and Analysis
- Synthesis and pharmacology of benzodiazepine derivatives
- Estrogen and related hormone effects
- Antioxidant Activity and Oxidative Stress
Universidade de Vigo
2012-2025
Institut Català d'Investigació Química
2012-2018
Institute of Science and Technology
2015-2018
University of Calgary
2018
Institució Catalana de Recerca i Estudis Avançats
2013
University of Göttingen
2013
Karlsruhe Institute of Technology
2013
Technische Universität Berlin
2013
University of Wisconsin–Madison
2013
University of the Basque Country
2009-2012
Iodine reagents have been identified as economically and ecologically benign alternatives to transition metals, although their application molecular catalysts in challenging C-H oxidation reactions has remained elusive. An attractive iodine catalysis is now shown promote the convenient conversion of carbon-hydrogen bonds into carbon-nitrogen with unprecedented complete selectivity. The reaction proceeds by two interlocked catalytic cycles comprising a radical chain reaction, which initiated...
An enantioselective catalytic vicinal diamination of styrenes is reported, which proceeds under entirely intermolecular reaction control. It relies on a chirally modified aryliodine(I) catalyst and within an iodine(I/III) manifold with conventional 3-chloroperbenzoic acid as terminal oxidant. environmentally benign solvent combination not only adds to the attractiveness process but also slows down rate undesired background reaction. A total 30 examples are presented, consistently provide...
Abstract Molecular structures of the most prominent chiral non‐racemic hypervalent iodine(III) reagents to date have been elucidated for first time. The formation a chirally induced supramolecular scaffold based on selective hydrogen‐bonding arrangement provides an explanation consistently high asymmetric induction with these reagents. As exploratory example, their scope as catalysts was extended enantioselective dioxygenation alkenes. A series terminal styrenes are converted into...
Die monumentale Plastik Elegie auf den Horizont des baskischen Künstlers Eduardo Chillida überwacht die Atlantikküste der Stadt Gijón. Eine ähnliche Bauform findet sich in Enantiodiskriminierung von Alkenen mit einem chiralen Iod(III)-Katalysator. In Zuschrift S. 422 diskutieren K. Muñiz et al. selektive Wasserstoffbrücken zur Bildung chiral induzierten supramolekularen Gerüsten Iod(III)-Katalysatoren und deren Einsatz einer intermolekularen enantioselektiven Diacetoxylierung....
Palladium catalysis has been instrumental in the development of intramolecular diamination alkenes. Reagent combinations a palladium catalyst and iodosobenzene diacetate or copper(II) salts, respectively, represent broad applicability mechanistic variation. Recent work established alternative copper bromine catalysts. The occupation with this reaction also contributed to high oxidation state metal alkene difunctionalization significantly broadened spectrum Pd-catalyzed C–N bond-forming...
Only I and N: Hypervalent iodine(III) reagents with two reactive IN single bonds have been isolated for the first time. Their solid-state solution structures provide evidence enhanced electrophilicity at iodine nucleophilic character of imine. As a result, improved reactivity in amination reactions unprecedented nitrogen-transfer under metal-free conditions are realized. Detailed facts importance to specialist readers published as "Supporting Information". Such documents peer-reviewed, but...
Internal affairs: the first general palladium-catalyzed intermolecular diamination of internal alkenes employs different nitrogen sources, which add to alkene in a regio- and diastereoselective fashion. The resulting products can be converted directly into known ligand motif.
Conditions for an attractive and productive protocol the position-selective intramolecular C-H amination of aliphatic groups (Hofmann-Löffler reaction) are reported employing sulfonimides as nitrogen sources. N-Iodosuccinimide is only required promoter this transformation, which conveniently initiated by visible light. The overall transformation provides pyrrolidines under mild selective conditions demonstrated 17 different substrates.
Abscisic acid (ABA) is an important carotenoid-derived phytohormone that plays essential roles in plant response to biotic and abiotic stresses as well various physiological developmental processes. In Arabidopsis, ABA biosynthesis starts with the epoxidation of zeaxanthin by DEFICIENT 1 (ABA1) enzyme, leading epoxycarotenoids; e.g., violaxanthin. The oxidative cleavage 9-cis-epoxycarotenoids, a key regulatory step catalyzed 9-CIS-EPOXYCAROTENOID DIOXYGENASE, forms xanthoxin, which converted...
Abstract Iodreagentien werden als ökonomisch und ökologisch ansprechende Alternativen zu Übergangsmetallen aufgefasst, obgleich ihr Einsatz molekulare Katalysatoren in anspruchsvollen C‐H‐Oxidationen weitgehend ausgeblieben ist. Hier wird eine attraktive Iodoxidationskatalyse vorgestellt, die bequeme Umwandlung von Kohlenstoff‐Wasserstoff‐ Kohlenstoff‐Stickstoff‐Bindungen mit bislang unerreichter vollständiger Selektivität ermöglicht. Die Reaktion verläuft innerhalb zweier miteinander...
An advanced protocol for the intramolecular C–H amination of alkyl groups via amidyl radicals (Hofmann–Löffler reaction) under homogeneous iodine catalysis is reported. This employs common mCPBA as terminal oxidant. It proceeds mild conditions, with complete chemoselectivity, compatible radical intermediates, and allows selective reaction secondary tertiary hydrocarbon bonds not restricted to benzylic amination. The involvement an iodine(III) catalyst state in C–N bond formation derives from...
A new Pd-catalyzed tandem intramolecular oxypalladation/Heck-type coupling between 2-alkynylphenols and alkenes is reported, leading to 3-(1-alkenyl)benzofurans. Participating include those substituted with an electron-withdrawing group (ester, ketone, amide, nitrile, sulfone), as well styrene. Remarkably, β-substituted-α,β-unsaturated carbonyl-type derivatives also participate effectively. The ready availability of alkynylphenols, together flexibility in the alkene choice, makes this simple...
Structurally diverse C3-alkenylbenzofurans, C3-alkenylindoles, and C4-alkenylisoquinolones are efficiently prepared by using consecutive Sonogashira cascade Pd-catalyzed heterocyclization/oxidative Heck couplings from readily available ortho-iodosubstituted phenol, aniline, benzamide substrates, alkynes, functionalized olefins. The cyclization of O- N-heteronucleophiles follows regioselective 5-endo-dig- or 6-endo-dig-cyclization modes, whereas the subsequent Heck-type coupling with both...
The potential of homogeneous oxidation catalysis employing bromine has remained largely unexplored. We herein show that the combination a tetraalkylammonium bromide and meta-chloroperbenzoic acid offers unique catalyst system for convenient selective saturated C(sp3 )-H bonds upon photochemical initiation with day light. This approach enables remote, intramolecular, position-selective C-H amination as demonstrated 20 different examples. For first time, an N-halogenated intermediate was...
A modified protocol has been identified for Pd-catalyzed intermolecular aminoacetoxylation of terminal and internal alkenes that enables the alkene to be used as limiting reagent. The results prompt a reassessment stereochemical course these reactions. X-ray crystallographic characterization two products, together with isotopic labeling studies, show amidopalladation step switches from cis-selective process under aerobic conditions trans-selective in presence diacetoxyiodobenzene.
A photochemical catalytic amination of arenes is presented. The reaction proceeds under benign iodine catalysis in the presence visible light as initiator and provides access to a range differently substituted arylamines. total 29 examples demonstrate broad applicability this mild oxidation method. scope could further be expanded silyl-tethered derivatives, which undergo intramolecular upon formation seven-membered heterocycles. Cleavage silicon tether corresponding 3-substituted anilines.
Palladium catalysis enables the regioselective difunctionalization of alkenes using saccharin as nitrogen source in initial step aminopalladation. Depending on reaction conditions, diamination or aminooxygenation pathways can be accessed hypervalent iodine reagents terminal oxidants. The allylic ethers originates from an unprecedented ambident behavior saccharin. participating palladium catalysts contain a palladium–saccharide unit. Two representative complexes this type could isolated and...
Nur I und N: Die erste Isolierung von hypervalenten Iod(III)-Reagentien mit zwei reaktiven I-N-Einfachbindungen wird beschrieben. Ihre Strukturen im Festkörper in Lösung wurden untersucht, Hinweise auf erhöhte Elektrophilie am Iod verstärkte Nucleophilie Stickstoff des Imins erhalten. Hieraus resultieren verbesserte Reaktivität Aminierungen bzw. die Möglichkeit zu bislang unbekannten Stickstofftransferreaktionen unter metallfreien Bedingungen.
Abstract Die Molekülstrukturen der gegenwärtig besten chiralen, nichtracemischen hypervalenten Iod(III)‐Reagentien wurden zum ersten Mal aufgeklärt. induzierte Bildung einer chiralen supramolekularen Struktur basierend auf Wasserstoffbrücken liefert eine Erklärung für die konsequent hohen asymmetrischen Induktionen mit diesen Reagentien. Ihr Anwendungsbereich wurde enantioselektive Dioxygenierung von Alkenen erweitert. Eine Reihe terminalen Styrolen entsprechend unter milden Bedingungen in...
Abstract The general synthesis, isolation and characterization of electrophilic iodine reagents the formula R 4 N[I(O 2 CAr) ] is reported. These compounds are air‐ moisture‐stable iodine(I) reagents, which were characterized including X‐ray analysis. They represent conceptually new with anions as stabilizers. display expected performance upon interaction electron‐rich substrates. these in a total 47 different reactions vicinal iodooxygenation alkenes studied some key features on revealed.
Zaxinone is an apocarotenoid regulatory metabolite required for normal rice growth and development. In addition, zaxinone has a large application potential in agriculture, due to its growth-promoting activity capability alleviate infestation by the root parasitic plant Striga through decreasing strigolactone (SL) production. However, poorly accessible scientific community because of laborious organic synthesis that impedes further investigation utilization. this study, we developed...
A computational study of the mechanism for iodine(III)-mediated oxidative amination alkenes explains experimentally observed substrate dependence on product distribution. Calculations with M06 functional have been carried out reaction between PhI(N(SO2 Me)2 )2 and three different representative substrates: styrene, α-methylstyrene, (E)-methylstilbene. All reactions start electrophilic attack by a cationic )(+) unit double bond, formation an intermediate single C-I bond planar sp(2)...
The yield of pearl millet, a resilient cereal crop crucial for African food security, is severely impacted by the root parasitic weed Striga hermonthica, which requires host-released hormones, called strigolactones (SLs), seed germination. Herein, we identify four SLs present in Striga-susceptible line SOSAT-C88-P10 (P10) but absent resistant 29Aw (Aw). We generate chromosome-scale genome assemblies, including gapless chromosomes each line. Striga-resistant Aw lacks 0.7 Mb segment containing...
The total synthesis of the stereoisomer muanlactam predicted by DP4+ calculations, which differed from that reported for natural product on relative configuration at C19, was completed, and structure polyenic macrolactam fully confirmed. Construction stereocenters involved iterative enantio- diastereoselective Krische's allylation reaction formal syn-1,3-diol addition a propargylic Grignard reagent to Ellman's chiral nonracemic tert-butylsulfinamide enantiopure amine fragment. conjugated...