Structural Snapshots of Reversible Carbon Dioxide Capture and (De)oxygenation at Group 14 Diradicaloids

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 8, 2024

Although diradicals should exhibit a rather small reaction barrier as compared to closed-shell species for activating kinetically inert molecules, the activation and functionalization of carbon dioxide with stable main-group remain virtually unexplored. In this work, we present thorough study on CO2 activation, reversible capture, (de)oxygenation mediated by Group 14 singlet (i.e., diradicaloids) [(ADC)E]2 (E = Si, Ge, Sn) based an anionic dicarbene (ADC) framework (ADC PhC{N(Dipp)C}2; Dipp 2,6-iPr2C6H3). readily undergo [4 + 2]-cycloadditions result in barrelene-type bis-metallylenes [(ADC)E]2(OC═O). The addition is E Ge; thus, detaches under vacuum or at elevated temperature regenerates [(ADC)Ge]2. [(ADC)Sn]2(OC═O) isolable but deoxygenates additional form [(ADC)Sn]2(O2CO) CO. [(ADC)Si]2(OC═O) extremely reactive could not be isolated detected it spontaneously reacts further yield elusive monomeric Si(IV) oxides [(ADC)Si(O)]2(COn) carbonates [(ADC)Si(CO3)]2(COn) (n 1 2) via CO2. molecular structures all compounds have been established X-ray diffraction, mechanistic insight their formation has suggested DFT calculations.

Language: Английский

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Hydride Shuttle Catalysis: From Conventional to Inverse Mode

JACS Au, Journal Year: 2024, Volume and Issue: 4(9), P. 3358 - 3369

Published: Aug. 19, 2024

Hydride shuttle catalysis has emerged as a powerful synthetic platform, enabling the selective formation of C–C bonds to yield sp3-rich structures. By virtue compelling reactivity sterically encumbered Lewis acids from frustrated pair regime, hydride enables regioselective functionalization alkyl amines at either α- or β-position. In contrast classical acid reactivity, increased steric hindrance prevents interaction with basic amine itself, instead leading reversible abstraction α-carbon. The created positive charge facilitates occurrence transformations before rebound similar capture event happen. this Perspective, we outline broad selection featuring catalysis, well recently developed approach inverse catalysis. Both strategies give rise wide array functionalized and offer elegant approaches otherwise elusive bond formations.

Language: Английский

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π‐Conjugation as a Direct Estimate of Lewis Acidity

Chemistry - An Asian Journal, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 6, 2024

A computational approach to directly estimate the relative acidity of a given Lewis acid is presented. This based on strength π-conjugation in trans-crotonaldehyde-Lewis complexes, species used well-known Childs' scale. It found that π-conjugative values by Energy Decomposition Analysis - Natural Orbital for Chemical Valence method strongly correlate not only with variation bond lengths system, which are greatly affected nature acid, but also downfield shifts experienced different nuclei conjugated system upon binding acid. These strong correlations indicate (easy-to-compute) energies can be as an alternative

Language: Английский

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Regiospecific Methylalumination of Silacyclopropenes: The Access to Z-1-Silyl-2-Aluminyl-Disubstituted Olefins

Inorganic Chemistry, Journal Year: 2024, Volume and Issue: 63(48), P. 22962 - 22972

Published: Nov. 18, 2024

A methodology to access Z-1-silyl-2-aluminyl-disubstituted olefins is developed. It relies on the uncatalyzed ring opening of silacyclopropenes in presence a stoichiometric amount trimethylaluminum. The resulting heterosubstituted alkenes exhibit particular interaction between electron-rich [Si-CH3] moiety and electron-deficient diorganoaluminyl group, similar geometrical features due proximity these two centers. This rationalized using experimental theoretical descriptors. regioselectivity functional tolerance methylalumination were also studied case unsymmetrical silacyclopropenes, ultimately transposed synthesis polymeric organoalane incorporating tricoordinated aluminum

Language: Английский

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Aluminium porphyrins catalyse the hydrogenation of CO2 withH2

Chemical Science, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Boron-based frustrated Lewis pairs (FLPs) have become well-established catalysts for the hydrogenation of a wide range functional groups. Conversely, aluminium-based FLP are less common, especially CO

Language: Английский

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