101-49-5Relevant articles and documents
Metal Triflates for the Production of Aromatics from Lignin
Deuss, Peter J.,Lahive, Ciaran W.,Lancefield, Christopher S.,Westwood, Nicholas J.,Kamer, Paul C. J.,Barta, Katalin,de Vries, Johannes G.
, p. 2974 - 2981 (2016)
The depolymerization of lignin into valuable aromatic chemicals is one of the key goals towards establishing economically viable biorefineries. In this contribution we present a simple approach for converting lignin to aromatic monomers in high yields under mild reaction conditions. The methodology relies on the use of catalytic amounts of easy-to-handle metal triflates (M(OTf)x). Initially, we evaluated the reactivity of a broad range of metal triflates using simple lignin model compounds. More advanced lignin model compounds were also used to study the reactivity of different lignin linkages. The product aromatic monomers were either phenolic C2-acetals obtained by stabilization of the aldehyde cleavage products by reaction with ethylene glycol or methyl aromatics obtained by catalytic decarbonylation. Notably, when the method was ultimately tested on lignin, especially Fe(OTf)3 proved very effective and the phenolic C2-acetal products were obtained in an excellent, 19.3±3.2 wt % yield.
Highly efficient and chemoselective interchange of 1,3-oxathioacetals and dithioacetals to acetals promoted by N-halosuccinimide
Karimi, Babak,Seradj, Hassan,Maleki, Jafar
, p. 4513 - 4516 (2002)
Highly efficient interconversion of a range of 1,3-oxathiolanes, 1,3-dithiolanes and 1,3-dithianes to their acetals at ambient temperature using N-bromosuccinimide or N-chlorosuccinimide and different types of alcohols and diols was investigated.
New Br?nsted-Lewis acidic quaternary ammonium ionic liquids: Synthesis, acidity determination and acidity-catalytic activity relationship
Yi, Fengping,Gao, Jie,Zhang, Lirong,Jiang, Xiaoyan
, p. 1260 - 1264 (2015)
A series of new Br?nsted-Lewis acidic ionic liquids, which are operational simplicity, high stability, low cost and applicable for scaling up, have been synthesized and their activity for acetalization was examined. The comprehensive studies on the acidity-catalytic performance relationship of the Br?nsted-Lewis acidic ionic liquids were performed. IR spectroscopy results confirmed that the new Br?nsted-Lewis acidic ionic liquids possess both Br?nsted and Lewis acid sites. The acidities were determined by Hammett method, and further studies on acidity-activity relationship revealed that the acidity played a key role in the acid-catalyzed probe reactions.
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Uemura,S. et al.
, p. 3285 - 3286 (1976)
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Masked formylation with 2-benzotriazolyl-1,3-dioxolane, a novel formyl cation equivalent
Katritzky, Alan R.,Odens, Herman H.,Voronkov, Michael V.
, p. 1886 - 1888 (2000)
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Tropylium salts as efficient organic Lewis acid catalysts for acetalization and transacetalization reactions in batch and flow
Lyons,Crocker,Enders,Nguyen
supporting information, p. 3993 - 3996 (2017/09/08)
Acetalization reactions play significant roles in the synthetically important masking chemistry of carbonyl compounds. Herein we demonstrate for the first time that tropylium salts can act as organic Lewis acid catalysts to facilitate acetalization and transacetalization reactions of a wide range of aldehyde substrates. This metal-free method works efficiently in both batch and flow conditions, prompting further future applications of tropylium organocatalysts in green synthesis.
Visible-light-induced acetalization of aldehydes with alcohols
Yi, Hong,Niu, Linbin,Wang, Shengchun,Liu, Tianyi,Singh, Atul K.,Lei, Aiwen
supporting information, p. 122 - 125 (2017/11/27)
In this work, we have achieved a simple and general method for acetalization of aldehydes by means of a photochemical reaction under low-energy visible light irradiation. A broad range of aromatic, heteroaromatic, and aliphatic aldehydes have been protected under neutral conditions in good to excellent yields using a catalytic amount of Eosin Y as the photocatalyst. Our visible light mediated acetalization strategies are successful for more challenging acid-sensitive aldehydes and sterically hindered aldehydes. Notably, this protocol is chemoselective to aldehydes, while ketones remain intact.
