21048-31-7Relevant academic research and scientific papers
Oxygen Atom Transfer With Niobocene Ketenes; Baeyer-Villiger Chemistry with Unusual Regioselectivities
Fermin, Maria C.,Bruno, Joseph W.
, p. 7545 - 7548 (1993)
Niobocene ketene complex 1 has been utilized as an oxygen atom transfer reagent, converting ketones and aldehydes to esters and carboxylic acids.The steric properties of compound 1 give rise to a series of relative migratory aptitudes that differs from those seen for peracids.The process may be rendered catalytic in 1 with methyltrifluoromethyldioxirane (4). Key Words: Baeyer-Villiger reaction, niobocene complexes, ketenes, oxygen transfer, dioxiranes
Hydroxyl radical-mediated oxidative cleavage of CC bonds and further esterification reaction by heterogeneous semiconductor photocatalysis
Hong, Mei,Jia, Rui,Miao, Hongyan,Ni, Bangqing,Niu, Tengfei,Wang, Hui
supporting information, p. 6591 - 6597 (2021/09/10)
A hydroxyl radical-mediated aerobic cleavage of alkenes and further sequence esterification reaction for the preparation of carbonyl compounds have been developed by using tubular carbon nitride (TCN) as a general heterogeneous photocatalyst under an oxygen atmosphere with visible light irradiation. This protocol has an excellent substrate scope and gives the desired aldehydes, ketones and esters in moderate to high yields. Importantly, this metal-free procedure employed photogenerated hydroxyl radicals in situ as green oxidation active species, avoiding the present additional initiators. The reaction could be carried out under solar light irradiation and was applicable to large-scale reactions. Furthermore, the recyclable TCN catalyst could be used several times without a significant loss of activities.
Intermolecular Carbonyl–olefin Metathesis with Vinyl Ethers Catalyzed by Homogeneous and Solid Acids in Flow
Cerón-Carrasco, José Pedro,Leyva-Pérez, Antonio,Pérez-Sánchez, Horacio,Rivero-Crespo, Miguel ángel,Tejeda-Serrano, María
supporting information, p. 3846 - 3849 (2019/11/11)
The carbonyl–olefin metathesis reaction has experienced significant advances in the last seven years with new catalysts and reaction protocols. However, most of these procedures involve soluble catalysts for intramolecular reactions in batch. Herein, we show that recoverable, inexpensive, easy to handle, non-toxic, and widely available simple solid acids, such as the aluminosilicate montmorillonite, can catalyze the intermolecular carbonyl–olefin metathesis of aromatic ketones and aldehydes with vinyl ethers in-flow, to give alkenes with complete trans stereoselectivity on multi-gram scale and high yields. Experimental and computational data support a mechanism based on a carbocation-induced Grob fragmentation. These results open the way for the industrial implementation of carbonyl–olefin metathesis over solid catalysts in continuous mode, which is still the origin and main application of the parent alkene–alkene cross-metathesis.
Experimental and Theoretical Studies on Gas-Phase Fragmentation Reactions of Protonated Methyl Benzoate: Concomitant Neutral Eliminations of Benzene, Carbon Dioxide, and Methanol
Xia, Hanxue,Zhang, Yong,Attygalle, Athula B.
, p. 1601 - 1610 (2018/07/29)
Protonated methyl benzoate, upon activation, fragments by three distinct pathways. The m/z 137 ion for the protonated species generated by helium-plasma ionization (HePI) was mass-selected and subjected to collisional activation. In one fragmentation path
Acid-catalyzed synthesis of functionalized arylthio cyclopropane carbaldehydes and ketones
Porcu, Stefania,Luridiana, Alberto,Martis, Alberto,Frongia, Angelo,Sarais, Giorgia,Aitken, David J.,Boddaert, Thomas,Guillot, Regis,Secci, Francesco
supporting information, p. 13547 - 13550 (2019/01/06)
A general strategy for the synthesis of arylthio cyclopropyl carbaldehydes and ketones via a Br?nsted acid catalyzed arylthiol addition/ring contraction reaction sequence has been exploited. The procedure led to a wide panel of cyclopropyl carbaldehydes in generally high yields and with broad substrate scope. Mechanistic aspects and synthetic applications of this procedure were investigated.
On the reactivity of imidazole carbamates and ureas and their use as esterification and amidation reagents
Heller, Stephen T.,Sarpong, Richmond
experimental part, p. 8851 - 8859 (2011/12/02)
The optimization, substrate scope, and mechanism of esterification and amidation of carboxylic acids mediated by imidazole-based reagents are discussed. The innate reactivity of carbonylimidazole reagents with a range of nucleophiles is also explored. New reagents developed for the synthesis of α,β-unsaturated esters are described, as are reagents for the preparation of tertiary amides directly from carboxylic acids.
Nucleophilic catalysis with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) for the esterification of carboxylic acids with dimethyl carbonate
Shieh, Wen-Chung,Dell, Steven,Repic, Oljan
, p. 2188 - 2191 (2007/10/03)
1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) is an effective nucleophilic catalyst for carboxylic acid esterification with dimethyl carbonate (DMC). The reaction pathway of this new class of nucleophilic catalysis has been studied. A plausible, multistep mech
Convenient syntheses of [18O]Benzyl alcohol and [13C-carboxy,18O1]Benzoic acid of high isotopic purity
Young, David J.,Robinson, Michael J.T.
, p. 121 - 126 (2007/10/03)
The title compounds may be prepared with high isotopic incorporation and in good yield.
