A5012977541- Asymmetric Synthesis and Catalysis
- Crystallization and Solubility Studies
- X-ray Diffraction in Crystallography
- Synthesis and Catalytic Reactions
- Synthetic Organic Chemistry Methods
- Chemical Synthesis and Reactions
- Asymmetric Hydrogenation and Catalysis
- Catalytic C–H Functionalization Methods
- Oxidative Organic Chemistry Reactions
- Radical Photochemical Reactions
- Sulfur-Based Synthesis Techniques
- Vanadium and Halogenation Chemistry
- Synthesis and Biological Evaluation
- Fluorine in Organic Chemistry
- Inorganic Fluorides and Related Compounds
- Crystallography and molecular interactions
- Metal-Catalyzed Oxygenation Mechanisms
- Cyclopropane Reaction Mechanisms
- Mesoporous Materials and Catalysis
- Chemical synthesis and alkaloids
- Chemical Synthesis and Characterization
Max-Planck-Institut für Kohlenforschung
2019-2022
Universitat de Barcelona
2013-2019
FC Barcelona
2017-2018
Instituto de Química Orgánica General
2017-2018
Institute for Biomedicine
2017-2018
Institut de Biomedicina de la Universitat de Barcelona
2014-2017
Reported here is a simple and practical functionalization of primary sulfonamides, by means pyrylium salt (Pyry-BF4 ), with nucleophiles. This reagent activates the poorly nucleophilic NH2 group in sulfonamide, enabling formation one best electrophiles organic synthesis: sulfonyl chloride. Because variety sulfonamides pharmaceutical contexts, special attention has been focused on direct conversion densely functionalized late-stage corresponding A nucleophiles could be engaged this...
Abstract Selective modification of heteroatom-containing aromatic structures is in high demand as it permits rapid evaluation molecular complexity advanced intermediates. Inspired by the selectivity deaminases nature, herein we present a simple methodology that enables NH 2 groups aminoheterocycles to be conceived masked handles. With aid pyrylium reagent and cheap chloride source, C( sp )‒NH can converted into )‒Cl bonds. The method characterized its wide functional group tolerance...
Abstract A highly efficient and straightforward aminoxylation of titanium(IV) enolates from ( S )‐ N ‐acyl‐4‐benzyl‐5,5‐dimethyl‐1,3‐oxazolidin‐2‐ones with TEMPO has been developed. wide array functional groups on the acyl moiety, including alkyl aryl substituents, olefins, esters, or α‐cyclopropyl, as well α‐trifluoromethyl groups, are tolerated. This transformation can therefore produce α‐aminoxylated adducts in excellent yields high diastereomeric ratios (d.r.). In turn, parallel...
Abstract Reported here is a simple and practical functionalization of primary sulfonamides, by means pyrylium salt (Pyry‐BF 4 ), with nucleophiles. This reagent activates the poorly nucleophilic NH 2 group in sulfonamide, enabling formation one best electrophiles organic synthesis: sulfonyl chloride. Because variety sulfonamides pharmaceutical contexts, special attention has been focused on direct conversion densely functionalized late‐stage corresponding A nucleophiles could be engaged this...
Simple treatment of chiral titanium(IV) enolates with diacyl peroxides produces highly diastereoselective decarboxylative alkylations to efficiently deliver the corresponding adducts, most which are not accessible through any current alkylating procedures. Such an unprecedented alkylation proceeds SET process that triggers decomposition peroxide into a carbon-centered radical finally combines resulting Cα radical. The procedure has been applied enantioselective synthesis arundic acid.
Aldol reactions of titanium enolates lactate-derived ethyl ketone 1 with other ketones proceed in a very efficient and stereocontrolled manner provided that further equivalent TiCl4 is added to the reacting mixture. The scope these encompasses simple such as acetone or cyclohexanone well contain potential chelating groups pyruvate esters α- β-hydroxy ketones.
Substrate-controlled Michael additions of the titanium(IV) enolate lactate-derived ketone 1 to acyclic α,β-unsaturated ketones in presence a Lewis acid (TiCl4 or SnCl4) provide corresponding 2,4-anti-4,5-anti dicarbonyl compounds good yields and excellent diastereomeric ratios. Likely, nucleophilic species involved such are bimetallic enolates that may add enones through cyclic transition states. Finally, further studies indicate structurally related β-benzyloxy chiral can also participate...
Quantum chemical calculations have unveiled the unexpected biradical character of titanium(IV) enolates from N-acyl oxazolidinones and thiazolidinethiones. The electronic structure these species therefore involves a valence tautomerism consisting an equilibrium between closed shell (formally Ti(IV) enolates) open shell, biradical, singlet Ti(III) states, whose origin is to be basically found in changes Ti–O distance. Spectroscopic studies intermediate lend support such model, which also...
A total synthesis of (+)-herboxidiene/GEX 1A has been accomplished from (R)- and (S)-lactate esters in a highly efficient manner. Key steps the involve substrate-controlled titanium-mediated aldol reactions chiral lactate-derived ethyl ketones, an oxa-Michael cyclization, Ireland-Claisen rearrangement, Suzuki coupling. Furthermore, computational studies reaction have unveiled dramatic influence intramolecular hydrogen bonds on stereochemical outcome such cyclizations, whereas biological...
Lewis acid mediated substrate-controlled reactions of the titanium(IV) enolates chiral α-benzyloxy ketones with conjugated nitroalkenes give 2,4-anti-4,5-syn Michael adducts in good yields and diastereomeric ratios. The supplementary plays a key role outcome these transformations, probably as consequence formation dimetallic that increase reactivity enolate direct approach nitroalkene. Importantly, most appropriate depends on electrophilic partner: TiCl4 is suitable for β-aryl-nitroalkenes,...
A novel approach to synthesize enantiomerically pure α-hydroxy carboxylic derivatives is reported. highly stereoselective oxidation of titanium(IV) enolates from chiral N-acyloxazolidinones performed with oxygen under simple experimental conditions that do not require any reducing steps. The success this depends on the biradical character enolates.
Abstract Conversion of chiral N‐acyl‐4‐benzyl‐oxazolidinones (I) to titanium enolates and subsequent quenching with TEMPO results in an efficient formation 2‐aminoxylation adducts excellent yields good enantioselectivities.
Abstract The title reaction proceeds in a very efficient and stereocontrolled manner provided that further equivalent of TiCl 4 is added to the reacting mixture.
Reactions of Ti(<sc>iv</sc>) enolates from <italic>N</italic>-acyl-4-<italic>tert</italic>-butyl-1,3-oxazolidine-2-thiones with TEMPO afford a single diastereomer aminoxylated adducts in high yields.