| 1. |
- Bermejo-López, Aitor, et al.
(author)
-
Selective Synthesis of Imines by Photo-Oxidative Amine Cross-Condensation Catalyzed by PCN-222(Pd)
- 2021
-
In: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 9:43, s. 14405-14415
-
Journal article (peer-reviewed)abstract
- Palladium-metalated PCN-222 enables the aerobic photo-oxidative cross-condensation of anilines with benzylic amines yielding a series of linear and cyclic imines. The reaction is very efficient under mild conditions, which allows the isolation of simple, yet elusive, intermediates such as 2-(benzylideneamino)-aniline and 2-(benzylideneamino)phenols. Recyclability studies show excellent activity and selectivity after five runs. The methodology was successfully applied for the synthesis of an antitumor agent (PMX-610).
|
|
| 2. |
- Bermejo-López, Aitor, et al.
(author)
-
Selective Synthesis of Imines via Photooxidative AmineCross-Condensation Catalyzed by PCN-222(Pd)
-
Other publication (other academic/artistic)abstract
- Palladium metallated PCN-222 enables the selective cross-condensation of anilines with benzylic aminesunder photooxidative conditions and at ambient temperature. The method affords a series of linear and cyclic Schiffbases. The mild conditions used in this catalytic system results in the isolation of resourceful intermediates such as 2-(benzylideneamino)aniline and 2-(benzylideneamino)phenols, which can be further modified.
|
|
| 3. |
- Carrasco, Sergio, et al.
(author)
-
Fast and Robust Synthesis of Metalated PCN-222 and Their Catalytic Performance in Cycloaddition Reactions with CO2
- 2019
-
In: Organometallics. - : American Chemical Society (ACS). - 0276-7333 .- 1520-6041. ; 38:18, s. 3429-3435
-
Journal article (peer-reviewed)abstract
- A simple and quick setup for the synthesis of PCN-222 and of a variety of metalated PCN-222(Co, Ni, Cu, and Zn), using of a microwave reactor, is reported for CO2 fixation. Metalation of prophyrins by microwave heating has been evaluated through UV-vis titration. PCN-222(M) were obtained in a three-step, one-pot reaction in a remarkable 72% yield in only 30 min. The materials have been characterized using a variety of techniques. A study of CO2 fixation through cycloaddition with epoxides and azidirines using metalated PCNs as catalysts is described. Cyclic carbonates and oxazolidinones were formed using CO2 at atmospheric pressure under mild conditions. Higher activity was observed when PCN-222(Co) was used compared to that with PCN-222(Ni, Cu, Zn).
|
|
| 4. |
- Carretero Cerdan, Alba, et al.
(author)
-
One-step microwave-assisted synthesis of amino-functionalized chromium(III) terephthalate MIL-101-NH2
- 2023
-
In: Materials Today Chemistry. - 2468-5194. ; 31
-
Journal article (peer-reviewed)abstract
- A single-step microwave (MW)-assisted protocol for the synthesis of MIL-101(Cr) and of MIL-101(Cr)-NH2 is described herein, based on the addition of NaF as the modulator instead of hydrofluoric acid to obtain the corresponding polymers in only 1 h with high crystallinity and yields (>70%, 0.5 g). Compared to classic solvothermal protocols (12-72 h, <30%), MW-assisted synthesis allowed shorter reaction time and improved yields, replacing N,N-dimethylformamide by water. Physicochemical properties of MIL-101(Cr)-NH2 and MIL-101(Cr) obtained through this MW-assisted procedure are more homogenous than those observed for the corresponding solvothermal counterparts, and interestingly, enhanced higher control over nanometric particle size (80-130 vs 400-1000 nm), lower polydispersity, and higher Brunauer-Emett-Teller surface area (2000-2700 vs 1800-2300 m2/g) were observed because of the better accessibility and diffusion of gases throughout the internal pores.& COPY; 2023 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
|
|
| 5. |
|
|
| 6. |
- Erbing, Elis, et al.
(author)
-
Base- and Additive-Free Ir-Catalyzed ortho-Iodination of Benzoic Acids : Scope and Mechanistic Investigations
- 2018
-
In: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 8:2, s. 920-925
-
Journal article (peer-reviewed)abstract
- A protocol for the C-H activation/iodination of benzoic acids catalyzed by a simple iridium complex has been developed. The method described in this paper allows the ortho-selective iodination of a variety of benzoic acids under extraordinarily mild conditions in the absence of any additive or base in 1,1,1,3,3,3-hexafluoroisopropanol as the solvent. The iridium catalyst used tolerates air and moisture, and selectively gives ortho-iodobenzoic acids with high conversions. Mechanistic investigations revealed that an Ir(III)/Ir(V) catalytic cycle operates, and that the unique properties of HFIP enables the C-H iodination using the carboxylic moiety as a directing group.
|
|
| 7. |
|
|
| 8. |
- García-Vázquez, Víctor, et al.
(author)
-
An Expedient Method for the Umpolung Coupling of Enols with Heteronucleophiles
- 2022
-
In: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 28:44
-
Journal article (peer-reviewed)abstract
- In this paper, we present an unprecedented and general umpolung protocol that allows the functionalization of silyl enol ethers and of 1,3-dicarbonyl compounds with a large range of heteroatom nucleophiles, including carboxylic acids, alcohols, primary and secondary amines, azide, thiols, and also anionic carbamates derived from CO2. The scope of the reaction also extends to carbon-based nucleophiles. The reaction relies on the use of 1-bromo-3,3-dimethyl-1,3-dihydro-1λ3[d][1,2]iodaoxole, which provides a key α-brominated carbonyl intermediate. The reaction mechanism has been studied experimentally and by DFT, and we propose formation of an unusual enolonium intermediate with a halogen-bonded bromide.
|
|
| 9. |
|
|
| 10. |
- Martín-Matute, Belén, et al.
(author)
-
Unraveling the Mechanism of the IrIII-Catalyzed Regiospecific Synthesis of α-Chlorocarbonyl Compounds from Allylic Alcohols
- 2020
-
In: Chemistry - A European Journal. - : Wiley. - 0947-6539 .- 1521-3765. ; 26:65, s. 14978-14986
-
Journal article (peer-reviewed)abstract
- We have used experimental studies and DFT calculations to investigate the IrIII-catalyzed isomerization of allylic alcohols into carbonyl compounds, and the regiospecific isomerization–chlorination of allylic alcohols into α-chlorinated carbonyl compounds. The mechanism involves a hydride elimination followed by a migratory insertion step that may take place at Cβ but also at Cα with a small energy-barrier difference of 1.8 kcal mol−1. After a protonation step, calculations show that the final tautomerization can take place both at the Ir center and outside the catalytic cycle. For the isomerization–chlorination reaction, calculations show that the chlorination step takes place outside the cycle with an energy barrier much lower than that for the tautomerization to yield the saturated ketone. All the energies in the proposed mechanism are plausible, and the cycle accounts for the experimental observations.
|
|
