2403-58-9Relevant articles and documents
Conjugate addition of acetal-derived benzyl radicals generated from low-valent titanium-mediated CO bond cleavage
Suga, Takuya,Nakamura, Masaharu,Takada, Ryusei,Ukaji, Yutaka
supporting information, p. 1258 - 1260 (2021/05/17)
A new method for the generation of benzyl radicals from acetals via low-valent titanium-mediated homolytic CO bond cleavage is presented. The low cost and availability of the developed titanium reagent enable efficient access to α-alkoxy carbon radical species via the developed reaction.
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.
Antimony(v) catalyzed acetalisation of aldehydes: An efficient, solvent-free, and recyclable process
Ugarte, Renzo Arias,Hudnall, Todd W.
, p. 1990 - 1998 (2017/06/09)
A highly selective, solvent-free process for the acetalisation of aldehydes was achieved by the use of a readily accessible antimony(v) catalyst which we previously prepared in our lab as a tetraarylstibonium triflate salt ([1][OTf]). High yields of the acetals were achieved in the presence of stoichimetric amounts of either triethoxymethane or triethoxysilane. It was found that triethoxymethane reactions required longer time to reach completion when compared to triethoxysilane reactions which were completed upon mixing of the reagents. The products can be easily separated from the catalyst by distillation which enabled further use of [1][OTf] in additional calytic reactions (up to 6 cycles). Moreover, [1]+ also catalyzed the deprotection of the acetals into their corresponding aldehydes using only water as a solvent.
Facile synthesis of Cu3(BTC)2/cellulose acetate mixed matrix membranes and their catalytic applications in continuous flow process
Hou, Junying,Luan, Yi,Huang, Xiubing,Gao, Hongyi,Yang, Mu,Lu, Yunfeng
, p. 9123 - 9129 (2017/08/29)
Metal-organic framework (MOF)-based mixed matrix membranes (MMMs) were fabricated by a combination of Cu3(BTC)2 MOF and polymer cellulose acetate. The cellulose acetate in the MMMs served as the matrix and the Cu3(BTC)2 MOF as the filler. The as-synthesized MMMs were utilized as a heterogeneous catalyst for aldehyde acetalization. The characterization techniques indicated that the Cu3(BTC)2 crystals were uniformly dispersed in the MMMs. The BET surface area of the Cu3(BTC)2-based MMM was measured to be 459 m2 g-1 at 60 wt% Cu3(BTC)2 loading. Furthermore, the MMMs served as an excellent catalyst under our continuous flow catalytic reaction conditions. The optimal catalytic result of benzaldehyde yield reached 94% with 60 wt% Cu3(BTC)2 loading of the MMMs at room temperature and the benzaldehyde diethyl acetal reached 0.59 mmol min-1 gCu-BTC-1.
Development of a novel Br?nsted acid UiO-66 metal-organic framework catalyst by postsynthetic modification and its application in catalysis
Miao, Zongcheng,Qi, Chao,Wensley, Allison M.,Luan, Yi
, p. 67226 - 67231 (2016/07/30)
A novel Br?nsted acid derived metal-organic framework (MOF) has been developed to serve as an efficient heterogeneous catalyst for the acetalization and Morita-Baylis-Hillman reaction. Aromatic sulfonic acid groups were successfully incorporated to the framework of UiO-66 by post-synthetic modifications using commercially available anhydridic reagents. The UiO-66-RArSO3H Br?nsted acid catalyst was fully characterized using SEM, PXRD, FTIR, TGA and N2 adsorption/desorption isotherms. Furthermore, efficient acetalization and Morita-Baylis-Hillman reactions were evaluated to demonstrate the high catalytic performance of the UiO-66-RArSO3H catalyst. The UiO-66-RArSO3H catalyst is compatible with a variety of substituted substrates and can be recycled five times without a compromise in the yield or selectivity.
Development of a SO3H-functionalized UIO-66 metal-organic framework by postsynthetic modification and studies of its catalytic activities
Luan, Yi,Zheng, Nannan,Qi, Yue,Yu, Jie,Wang, Ge
, p. 4268 - 4272 (2015/03/30)
A novel metal-organic framework UiO-66-NH2-derived Br?nsted acid catalyst was synthesized on a gram scale by employing a postsynthetic modification strategy under mild conditions. The nanomorphology of the catalyst was designed and developed to enhance its catalytic performance. Acetalization and benzimidazole formation were evaluated to demonstrate the high reactivity and selectivity of the nanoscaled UiO-66-NH-RSO3H catalyst, which were found to be comparable to the reactivity and selectivity of the strong homogeneous Br?nsted acid catalyst. Furthermore, the UiO-66-NH-RSO3H catalyst was recycled several times without compromising the yield and selectivity. A novel metal-organic framework UiO-66-NH2-derived Br?nsted acid catalyst is synthesized by employing a postsynthetic modification strategy under mild conditions. Acetalization and benzimidazole formation are evaluated to demonstrate the high reactivity and selectivity of the nanoscaled UiO-66-NH-RSO3H catalyst.
Bis(perfluorooctanesulfonyl)imide supported on fluorous silica gel: Application to protection of carbonyls
Hong, Mei,Xiao, Guomin
experimental part, p. 121 - 126 (2012/08/28)
The immobilization of bis(perfluorooctanesulfonyl)imide (HNPf2) on fluorous silica gel (FSG) and its utilization in protection of carbonyls have been investigated. This system is reasonably general and can be applied to converting several carbonyls to the corresponding acetals and ketals in good to excellent yields. There is no need for the use of anhydrous solvents or inert atmosphere. Recycling studies have shown that the FSG-supported HNPf2 catalyst can be readily recovered and reused several times without significant loss of activity.
Gallium triiodide as a highly efficient and mild catalyst for the diethyl acetalization of carbonyl compounds
Ding, Jin-Chang,Xu, Rong,Liu, Miao-Chang,Chen, Xi-An,Wu, Hua-Yue
experimental part, p. 566 - 568 (2009/07/18)
Diethyl acetals were obtained from carbonyl compounds in good to excellent yields under mild reaction conditions in the presence of triethyl orthoformate and a catalytic amount of gallium triiodide in anhydrous ethanol.
Nucleophilic phosphine-catalyzed [3+2] cycloaddition of allenes with N-(thio)phosphoryl imines and acidic methanolysis of adducts N-(thio)phosphoryl 3-pyrrolines: a facile synthesis of free amine 3-pyrrolines
Zhang, Bo,He, Zhengrong,Xu, Silong,Wu, Guiping,He, Zhengjie
, p. 9471 - 9479 (2008/12/22)
In this report, the dipolarophile imines with easily removable activating group O,O-diethyl(thio)phosphoryl have been investigated in the nucleophilic phosphine-catalyzed [3+2] cycloaddition reaction of electron-deficient allenes. Under the catalysis of a tertiary phosphine, N-(thio)phosphorylimines readily undergo the [3+2] cycloaddition reaction with ethyl 2,3-butadienoate or ethyl 2,3-pentadienoate, affording the corresponding N-(thio)phosphoryl 3-pyrrolines in moderate to high yields with good diastereoselectivity. Removal of the (thio)phosphoryl group from the adducts has been successfully achieved via the acidic methanolysis of the P-N bond, giving the free amine 3-pyrrolines in fair to good yields without severe aromatization. Thus, a facile synthesis of N-unsubstituted 3-pyrrolines is established from the phosphine-catalyzed [3+2] cycloaddition reaction of allenes with imines.
Iron(III) tosylate in the preparation of dimethyl and diethyl acetals from ketones and β-keto enol ethers from cyclic β-diketones
Mansilla, Horacio,Afonso, Maria M.
, p. 2607 - 2618 (2008/12/22)
An efficient method for conversion of ketones to their corresponding dimethyl and diethyl acetals and of cyclic β-diketones into β-keto enol ethers using Fe(OTs)3 as a catalyst is described. Copyright Taylor & Francis Group, LLC.
