Syntheses of Phosphonium Salts from Phosphines and Carbenium: Efficient CO2 Fixation and Phase‐Transfer Catalysts

Shaikh, Aslam C.; Veleta, José M; Bloch, Jan; Goodman, Hannah J.; Gianetti, Thomas L.

doi:10.1002/ejoc.202000221

Cited by 4 publications

(2 citation statements)

References 55 publications

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“…This is the first example of the recycling of a plasma‐immobilized catalyst, although the yields gradually decreased after the second run [32] . Gianetti's group developed the bifunctional phosphonium salt 53 , prepared from tris‐(2,6‐dimethoxyphenyl)‐carbenium and an aminophosphine, for CO 2 fixation reactions with epoxides under mild conditions [33] . The catalyst 53 also acted as an efficient phase‐transfer catalyst for the alkylation of 1,3‐dicarbonyl compounds 54 (Scheme 16).…”

Section: Annulation Reactions: [2+1] [2+1+1] [3+2] [4+1] and [4+2mentioning

confidence: 99%

Recent Advances in Phosphonium Salt Catalysis

Liu

Guo

2021

Adv Synth Catal

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Section: Annulation Reactions: [2+1] [2+1+1] [3+2] [4+1] and [4+2mentioning

confidence: 99%

Recent Advances in Phosphonium Salt Catalysis

Liu

Guo

2021

Adv Synth Catal

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“…[ 14] Our group has recently reported that phosphines react in a similar manner, even with the more electron-rich hexametoxytriphenyl-carbenium ion. [15] Interestingly, trioxatriangulenium ion (TOTA + , Figure 1b), the heterocyclic fused analog of hexametoxytriphenyl-carbenium ion, first reported by Smith et. al.…”

mentioning

confidence: 95%

Trioxatriangulenium (TOTA+) as a Robust Carbon-based Lewis Acid in Frustrated Lewis Pair Chemistry

Shaikh¹,

Veleta²,

Moutet³

et al. 2020

Preprint

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We report the reactivity between the Lewis acidic trioxatriangulenium ion (TOTA+) and a series of Lewis bases such as phosphines and N-heterocyclic carbene (NHC). The nature of the Lewis acid-base interaction was analyzed via variable temperature (VT) NMR spectroscopy, single-crystal X-ray diffraction, UV-visible spectroscopy, and DFT calculations. While small and strongly nucleophilic phosphines, such as PMe3, led to the formation of a stable Lewis acid-base adduct, frustrated Lewis pairs (FLPs) were observed for sterically hindered bases such as P(tBu)3. The TOTA+-P(tBu)3 FLP was characterized as an encounter complex, and was found to promote the heterolytic cleavage of disulfide bonds, formaldehyde fixation, dehydrogenation of 1,4-cyclohexadiene, heterolytic cleavage of C–Br bond, and interception of Staudinger reaction intermediate. Moreover, TOTA+ and NHC was found to first undergo single-electron transfer (SET) to form [TOTA]•[NHC] •+, which was confirmed via electron paramagnetic resonance (EPR) spectroscopy, and subsequently form a [TOTA-NHC]+ adduct or a mixture of products depending the reaction condition used.

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