4 research outputs found
Heteroatom-Tethered ω-Alkenylallylboronates: Stereoselective Synthesis of Heterocyclic Derived Alcohols
The synthesis of ω-alkenylallylboronates using a heteroatom tether to join both functional groups is described for the first time. Then, these unprecedented compounds were used in a tandem Brønsted acid catalyzed allylboration/ring-closing metathesis (RCM) reaction affording heterocyclic derived alcohols as single diastereoisomers. The low enantioselectivity observed in the asymmetric version using a chiral phosphoric acid catalyst was studied theoretically
Hexagonal Hybrid Bismuthene by Molecular Interface Engineering
High-quality devices based on layered heterostructures are typically built from materials obtained by complex solid-state physical approaches or laborious mechanical exfoliation and transfer. Meanwhile, wet-chemically synthesized materials commonly suffer from surface residuals and intrinsic defects. Here, we synthesize using an unprecedented colloidal photocatalyzed, one-pot redox reaction a few-layers bismuth hybrid of “electronic grade” structural quality. Intriguingly, the material presents a sulfur-alkyl-functionalized reconstructed surface that prevents it from oxidation and leads to a tuned electronic structure that results from the altered arrangement of the surface. The metallic behavior of the hybrid is supported by ab initio predictions and room temperature transport measurements of individual nanoflakes. Our findings indicate how surface reconstructions in two-dimensional (2D) systems can promote unexpected properties that can pave the way to new functionalities and devices. Moreover, this scalable synthetic process opens new avenues for applications in plasmonics or electronic (and spintronic) device fabrication. Beyond electronics, this 2D hybrid material may be of interest in organic catalysis, biomedicine, or energy storage and conversion
Heteroatom-Tethered ω-Alkenylallylboronates: Stereoselective Synthesis of Heterocyclic Derived Alcohols
The synthesis of ω-alkenylallylboronates using a heteroatom tether to join both functional groups is described for the first time. Then, these unprecedented compounds were used in a tandem Brønsted acid catalyzed allylboration/ring-closing metathesis (RCM) reaction affording heterocyclic derived alcohols as single diastereoisomers. The low enantioselectivity observed in the asymmetric version using a chiral phosphoric acid catalyst was studied theoretically
Solid-catalyzed synthesis of isomers-free terpinen-4-ol
[EN] Terpinen-4-ol is a natural product with wide application in the fragrance and agrochemical industry, currently extracted from tea tree oil or synthesized from either base-promoted rearrangement of 1,4-cineol or acid-catalyzed hydration of limonene. However, these synthetic processes, based on aggressive, unrecoverable homogeneous reagents, are non-selective and give significant amounts of isomers, which severely complicate and make more expensive the purification of the active substance. Here we show the isomers-free synthesis of terpinen-4-ol, exclusively over solid catalysts such as alumina, nanotitania and Pd/C, in >60% yield, by selective epoxidation, isomerization of terpinolene epoxide and allyl alcohol hydrogenation. The synthesis can be performed either in batch or in flow mode for the isomerization of terpinolene epoxide. The use of bare nanotitania as a selective epoxide isomerization catalyst, here demonstrated, opens new ways for the synthesis of quaternary alcohols.ITQ thanks IFF for its continuous support and collaboration. Financial support by the project PID2020-115100GB-I00 (funded by Spanish MCIINN, MCIN/AEI/10.13039/501100011033MICIIN) is acknowledged. F. G.-P. thanks ITQ for the concession of a contract. We thank Dr. J. Oliver-Meseguer for performing the epoxidation reactions with alumina.Garnes Portolés, F.; López Cruz, C.; Sánchez Quesada, J.; Espinós Ferri, E.; Leyva Perez, A. (2022). Solid-catalyzed synthesis of isomers-free terpinen-4-ol. Molecular Catalysis. 533:1-9. https://doi.org/10.1016/j.mcat.2022.1127851953