103-37-7Relevant articles and documents
Visible-light-initiated manganese-catalyzed Giese addition of unactivated alkyl iodides to electron-poor olefins
Dong, Jianyang,Wang, Xiaochen,Wang, Zhen,Song, Hongjian,Liu, Yuxiu,Wang, Qingmin
, p. 11707 - 11710 (2019)
Herein, we report a mild protocol for direct visible-light-initiated Giese addition of unactivated alkyl iodides to electron-poor olefins (Michael acceptors) with catalysis by decacarbonyl dimanganese, Mn2(CO)10, an inexpensive earth-abundant-metal catalyst. This protocol is compatible with a wide array of sensitive functional groups and has a broad substrate scope with regard to both the alkyl iodide and the Michael acceptor.
Palladium nanoparticles obtained from palladium salts and tributylamine in molten tetrabutylammonium bromide: Their use for hydrogenolysis-free hydrogenation of olefins
Le Bras, Jean,Mukherjee, Deb Kumar,Gonzalez, Sara,Tristany, Mar,Ganchegui, Benjamin,Moreno-Manas, Marcial,Pleixats, Roser,Henin, Francoise,Muzart, Jacques
, p. 1550 - 1553 (2004)
Carbon-carbon double bonds have been selectively hydrogenated at room temperature in the presence of benzyloxy groups using an atmospheric pressure of hydrogen, toluene or [bmim]PF6 as the solvent and palladium nanoparticles stabilized with tetrabutylammonium bromide. The system [bmim]PF6/palladium nanoparticles can be recycled without noticeable decrease of activity.
Synthesis of butyrate using a heterogeneous catalyst based on polyvinylpolypyrrolidone
Wang, Song,Chang, Qian-Qian,Shawgi, Nazar,Li, San-Xi,Zhang, Lin-Nan
, p. 538 - 544 (2016)
A heterogeneous polyvinylpolypyrrolidone supported Br?nsted acidic catalyst ([PVPP-BS]HSO4) was used to synthesize butyrate in this paper. The prepared catalysts were characterized by FT-IR, TG, and FESEM and their catalytic activity in butyric acid esterification with benzyl alcohol was investigated. The influencing factors such as the amount of catalyst, reaction temperature, and reaction time were carefully studied. Under the optimized condition with the butyric acid to benzyl alcohol mole ratio of 1 : 1.2 and the reaction temperature of 130°C, the yield of benzyl butyrate reached 96.8 % within 4 h in the presence of 8 mass % of catalyst. Moreover, the catalyst could be reused six times without noticeable drop in activity. This catalyst was also used to synthesize other kinds of butyrates achieving the butyrate yield above 90 %.
Glycoluril as an efficient molecular template for intramolecular Claisen-type condensations
Sun, Sengen,Edwards, Louise,Harrison, Paul
, p. 437 - 448 (1998)
The readily prepared 3,4,7,8-tetramethylglycoluril 1 acts as a template to promote efficient intramolecular Claisen-like condensations between two acyl groups which are attached to the N-1 and N-6 positions. Thus, two sequential acylations of 1 give symmetric or unsymmetric diacylglycolurils 9-18 in good yield. Treatment of 9-18 with lithium tert-alkoxides furnishes N-(β-ketoacyl)glycolurils 19-27 under mild conditions and in high yields; rate-limiting deprotonation, predominantly on the least substituted of the two acyl groups, precedes a fast intramolecular Claisen-type condensation. Reduction of the keto group in 19 and 26, followed by elimination of water gives alk-2-enoylglycolurils 6 and 7; conjugate hydride addition (L-Selectride) then gives alkanoylglycoluril 5. Compounds 5-7 undergo further rounds of N-acylation then intramolecular condensation. Linear chains can thus be constructed on 1 by repetitive sequences of acylation-condensation-functional group transformation. N1-Alk-2-enoyl-N6-alkanoylglycolurils 14-17 also afford condensation products with high selectivity upon treatment with L-Selectride, effecting a method for net reversal of the regioselectivity observed in the base-promoted rearrangement. The synthesized chains can be readily removed from the template, regenerating 1. The efficiency of the condensation reaction, the sequence of transformations and the ability to grow linear carbon chains in a repetitive manner mimic these aspects of the catalytic cycle of fatty acid synthases and polyketide synthases.
N, O-ligand accelerated zinc-catalyzed transesterification of alcohols with vinyl esters
Mino, Takashi,Hasegawa, Tae,Shirae, Yoshiaki,Sakamoto, Masami,Fujita, Tsutomu
, p. 4389 - 4396 (2007)
N-Phenyldiethanolamine (1f) is an efficient ligand for zinc-catalyzed transesterification of alcohols with vinyl acetate (R3 = Me) at room temperature. In the case of using other vinyl esters (R3 = Et, n-Pr, Ph), the corresponding products were easily obtained in the presence of pyridine-type ligand 2 instead of aminoalcohol 1f.
Metal-Free Direct Oxidation of Aldehydes to Esters Using TCCA
Gaspa, Silvia,Porcheddu, Andrea,De Luca, Lidia
, p. 3666 - 3669 (2015)
Aromatic and aliphatic aldehydes are simply converted into esters by an efficient oxidative esterification carried out under mild conditions. The aldehydes are converted in situ into their corresponding acyl chlorides, which are then reacted with primary and secondary aliphatic, benzylic, allylic, and propargylic alcohols and phenols. A variety of esters are obtained in high yields.
Ionic liquids as reaction media for esterification of carboxylate sodium salts with alkyl halides
Brinchi,Germani,Savelli
, p. 2027 - 2029 (2003)
Ionic liquids based on 1,3-dialkylimidazolinium methanesulfonate have been used as effective reusable reaction media in the esterification of several carboxylate sodium salts with different alkyl halides. Products are easily isolated by extraction with ether, and the protocol is mild and green, compared to the existing methods based on toxic solvents. Proper 'design' of the ionic liquid allows us to obtain esters always in quantitative yields.
The combine use of ultrasound and lipase immobilized on co-polymer matrix for efficient biocatalytic application studies
Badgujar, Kirtikumar Chandulal,Bhanage, Bhalchandra Mahadeo
, p. 255 - 264 (2015)
In this work, we have investigated the combine use of ultrasound and lipase (Pseudomonas cepacia: PCL) immobilized on co-polymer of polyvinyl alcohol (PVA) and chitosan (CHI) for biocatalytic applications. Initially, we have screened different free and immobilized biocatalysts to find-out the robust biocatalyst. The immobilized biocatalyst PVA:CHI:PCL (5:5:2.5) worked as a robust biocatalyst to provide superior conversion (99%) for the synthesis of model ultrasound assisted reaction. Subsequently, various reaction parameters were optimized in details to obtain the higher yield. Besides this, developed biocatalytic protocol was used to synthesize various industrially important butyrate compounds which provided excellent conversion of 99% under ultrasonic conditions. The developed biocatalyst showed excellent recyclability upto studied five cycles under ultrasonic condition. The immobilized PVA:CHI:PCL biocatalyst displayed 2.4 folds higher activity as compared to free lipases in ultrasonic condition. Moreover, PVA:CHI:PCL biocatalyst in ultrasound media showed 4.5 folds higher activity as compared to free lipases in conventional media. The energy assessment was performed which demonstrated feasibility of combine use of immobilization and ultrasonication to carry out efficient biocatalytic process.
Tandem Continuous Flow Curtius Rearrangement and Subsequent Enzyme-Mediated Impurity Tagging
Baumann, Marcus,Leslie, Alexander,Moody, Thomas S.,Smyth, Megan,Wharry, Scott
, p. 452 - 456 (2021)
The use of continuous flow as an enabling technology within the fine chemical and pharmaceutical industries continues to gain momentum. The associated safety benefits with flow for handling of hazardous or highly reactive intermediates are often exploited to offer industrially relevant and scalable Curtius rearrangements. However, in many cases the Curtius rearrangement requires excess nucleophile for the reaction to proceed to high conversions. This can complicate work procedures to deliver high-purity products. However, tandem processing and coupling of the Curtius rearrangement with an immobilized enzyme can elegantly facilitate chemoselective tagging of the residual reagent, resulting in a facile purification process under continuous flow.
Efficient Enzymatic Preparation of Flavor Esters in Water
Perdomo, Igor Chiarelli,Gianolio, Stefania,Pinto, Andrea,Romano, Diego,Contente, Martina Letizia,Paradisi, Francesca,Molinari, Francesco
, p. 6517 - 6522 (2019)
A straightforward biocatalytic method for the enzymatic preparation of different flavor esters starting from primary alcohols (e.g., isoamyl, n-hexyl, geranyl, cinnamyl, 2-phenethyl, and benzyl alcohols) and naturally available ethyl esters (e.g., formate, acetate, propionate, and butyrate) was developed. The biotransformations are catalyzed by an acyltransferase from Mycobacterium smegmatis (MsAcT) and proceeded with excellent yields (80-97%) and short reaction times (30-120 min), even when high substrate concentrations (up to 0.5 M) were used. This enzymatic strategy represents an efficient alternative to the application of lipases in organic solvents and a significant improvement compared with already known methods in terms of reduced use of organic solvents, paving the way to sustainable and efficient preparation of natural flavoring agents.
