122-70-3Relevant articles and documents
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 (2019/06/20)
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.
Zirconocene-catalyzed direct (trans)esterification of acyl acids (esters) and alcohols in a strict 1:1 ratio under solvent-free conditions
Tang, Zhi,Jiang, Qiutao,Peng, Lifen,Xu, Xinhua,Li, Jie,Qiu, Renhua,Au, Chak-Tong
supporting information, p. 5396 - 5402 (2017/11/22)
A highly efficient way for the direct (trans)esterification of acyl acids (esters) and alcohols in a strict 1:1 ratio using a zirconocene complex (1, 1 mol%), a strong Lewis acid of good water tolerance, as a catalyst under solvent-free conditions has been developed. A wide range of acid and alcohol (esters) substrates undergo (trans)esterification to produce carboxylic ester motifs in moderate to good or excellent yields with good functional tolerance, such as that towards C-Br as well as CC and CC bonds. And complex 1 can be recycled six times without showing a significant decline in catalytic efficiency. It was demonstrated that cyclandelate, which is used to treat high blood pressure as well as heart and blood-vessel diseases, can be directly synthesized on a gram scale with 81% yield (6.70 g) using complex 1.
Transfer Hydro-dehalogenation of Organic Halides Catalyzed by Ruthenium(II) Complex
You, Tingjie,Wang, Zhenrong,Chen, Jiajia,Xia, Yuanzhi
, p. 1340 - 1346 (2017/02/10)
A simple and efficient Ru(II)-catalyzed transfer hydro-dehalogenation of organic halides using 2-propanol solvent as the hydride source was reported. This methodology is applicable for hydro-dehalogenation of a variety of aromatic halides and α-haloesters and amides without additional ligand, and quantitative yields were achieved in many cases. The potential synthetic application of this method was demonstrated by efficient gram-scale transformation with catalyst loading as low as 0.5 mol %.
Reductive dehalogenation method of organic halide
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Paragraph 0087; 0088; 0089; 0090; 0091; 0092, (2017/08/28)
The invention discloses a reductive dehalogenation method of an organic halide. In the inert gas atmosphere, the organic halide shown as the formula I or the formula II is subjected to reductive dehalogenation to generate an organic compound shown as the formula III or the formula IV (the formulas are shown as the description) in the presence of a catalyst, alkali and a solvent, wherein the reaction temperature is controlled to 90-100 DEG C. The reductive dehalogenation method has the advantages that the range of substrates is widened; the solvent in use does not need extra phosphorous ligands, the price is relatively cheap, and the consumption can be greatly reduced to 0.1 mol%; the solvent in use serves as a hydrogen source and reacts, the operation is simple, a lot reactions can reach quantitative yields, and when the reactions are scaled up to gram level reactions, almost quantitative yields can still be achieved.
A microwave-assisted highly practical chemoselective esterification and amidation of carboxylic acids
Pathak, Gunindra,Das, Diparjun,Rokhum, Lalthazuala
, p. 93729 - 93740 (2016/10/21)
The ubiquitousness of esters and amide functionalities makes their coupling reaction one of the most sought-after organic transformations. Herein, we have described an efficient microwave-assisted synthesis of esters and amides. Soluble triphenylphosphine, in conjugation with molecular iodine, gave the desired products without the requirement for a base/catalyst. In addition, a solid-phase synthetic route is incorporated for the said conversion, which has added advantages over solution-phase pathways, such as low moisture sensitivity, easy handling, isolation of the product by simple filtration, and reusability. In short, our method is simple, mild, green, and highly chemoselective in nature.
N-Heterocyclic carbene-mediated redox condensation of alcohols
Kato, Terumasa,Matsuoka, Shin-Ichi,Suzuki, Masato
supporting information, p. 8569 - 8572 (2016/07/13)
N-Heterocyclic carbenes (NHCs) with a variety of oxidants promote the Mitsunobu-type coupling reactions of alcohols with phenols, carboxylic acids, and phthalimide. Experiments using a chiral alcohol indicate that these reactions proceed via SN1 or SN2 pathways depending on the polarity of the used solvents. The NHCs are consumed as reducing reagents to form their oxides as readily separable byproducts.
Efficient O-Acylation of Alcohols and Phenol Using Cp2TiCl as a Reaction Promoter
Durán-Pe?a, María Jesús,Botubol-Ares, José Manuel,Hanson, James R.,Hernández-Galán, Rosario,Collado, Isidro G.
supporting information, p. 3584 - 3591 (2016/07/28)
A method has been developed for the conversion of primary, secondary, and tertiary alcohols, and phenol, into the corresponding esters at room temperature. The method uses a titanium(III) species generated from a substoichiometric amount of titanocene dichloride together with manganese(0) as a reductant, as well as methylene diiodide. It involves a transesterification from an ethyl ester, or a reaction with an acyl chloride. A radical mechanism is proposed for these transformations.
Recyclable hypervalent iodine(III) reagent iodosodilactone as an efficient coupling reagent for direct esterification, amidation, and peptide coupling
Tian, Jun,Gao, Wen-Chao,Zhou, Dong-Mei,Zhang, Chi
supporting information; experimental part, p. 3020 - 3023 (2012/08/07)
A hypervalent iodine(III) reagent plays a novel role as an efficient coupling reagent to promote the direct condensation between carboxylic acids and alcohols or amines to provide esters, macrocyclic lactones, amides, as well as peptides without racemization. The regeneration of iodosodilactone (1) can also be readily achieved. The intermediate acyloxyphosphonium ion C from the activation of a carboxylic acid is thought to be involved in the present esterification reaction.
Synthesis of aromatic alcohols and their alkanoic acid esters
Mamedov
, p. 408 - 410 (2008/02/03)
The reaction of benzene with ethylene and propylene oxides in a helium atmosphere with aluminum chloride as a catalyst and the esterification of the resulting alcohols with saturated monocarboxylic acids in the presence of the heterogeneous catalyst KU-2-8 were studied. Pleiades Publishing, Inc., 2006.
Scope and mechanistic insights into the use of tetradecyl(trihexyl) phosphonium bistriflimide: A remarkably selective ionic liquid solvent for substitution reactions
McNulty, James,Nair, Jerald J.,Cheekoori, Sreedhar,Larichev, Vladimir,Capretta, Alfredo,Robertson
, p. 9314 - 9322 (2007/10/03)
A survey of substitution reactions conducted in a phosphonium bistriflimide ionic liquid is presented. The results demonstrate high selectivity favoring substitution over typically competitive elimination and solvolytic processes even when challenging secondary and tertiary electrophiles are employed. The first reports of Kornblum substitution reactions in an ionic liquid are described that proceed with very high chemoselectivity in favor of nitro over nitroso products and elimi nation side products. The structure-reactivity study indicates that these reactions proceed through a narrow spectrum of pathways ranging from straight SN2 to a preassociation pathway along a saddle point that approaches the SN1 limit. The barrier to the formation of dissociated carbocations is attributed to the structural features of this ionic liquid that favor intervention of the associated nucleophile over dissociation, also preventing cross over to E1 processes. The lack of any basic entity in the phosphonium bistriflimide ionic liquid appears to prevent any potential base-mediated elimination reactions, which makes this a highly selective medium for use in general substitution reactions.