- Multi-gram preparation of cinnamoyl tryptamines as skin whitening agents through a chemo-enzymatic flow process
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A 2-step flow-based chemo-enzymatic synthesis of selected cinnamoyl tryptamines as potential cosmetic ingredients has been developed. A first reaction catalyzed by immobilized Pd(OAc)2 gave the acyl donors employed as starting material in the s
- Padrosa, David Roura,Contente, Martina L.
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- Regio- and Stereoselective Chan-Lam-Evans Enol Esterification of Carboxylic Acids with Alkenylboroxines
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Efficient and scalable Cu(II)-mediated enol esterification methodology of carboxylic acids from alkenyl boroxines and boronic acids is presented. The reaction shows a wide scope in aliphatic and aromatic carboxylic acids in combination with several alkenyl boroxines. In the case of 2-substituted alkenyl boroxines the double bond configuration was fully retained in the enol ester product. Also N-hydroxyimides and imides could be transformed in the respective amidooxy vinyl enol ethers and vinyl enamides. Finally, with the exception of methionine, all other 19 canonical amino acids showed their compatibility to give the enol esters in a stereoselective fashion. (Figure presented.).
- Steemers, Luuk,Wijsman, Linda,van Maarseveen, Jan H.
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supporting information
p. 4241 - 4245
(2018/10/02)
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- Palladium(II) acetate as catalyst in transvinylation reactions of hydroxycinnamic acid and its derivatives
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The study on application of palladium(II) acetate as catalyst in transvinylation reactions of hydroxycinnamic acids has been done. This study was intended to assess the capability of palladium(II) acetate as a safer replacement for mercuric(II) catalysts
- Kadidae,Usami,Honda
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p. 589 - 593
(2018/02/09)
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- Reusable rhodium catalyst for the selective transvinylation of sp2-C linked carboxylic acid
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The vinyl benzoate derivatives were successfully synthesized by the transvinylation reactions that vinyl group transferred from vinyl acetate to aromatic carboxylic acids with the recoverable catalyst RhCl3·3H2O. This catalyst features air stable and tolerance of water, good reusable ability, meanwhile, shows high selectivity for aromatic carboxylic acid in the presence of phenolic hydroxyl. With this method, a variety of vinyl benzoate derivatives can be produced with up to 95% yield.
- Jiang, Ruihang,Chen, Zhangpei,Zhan, Kun,Liu, Lei,Zhou, Junjie,Ai, Yongjian,Li, Shuang,Bao, Hongjie,Hu, Ze'nan,Qi, Li,Wang, Jingting,Sun, Hong-bin
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p. 3279 - 3282
(2018/07/21)
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- Chemo-enzymatic synthesis of vinyl and L-ascorbyl phenolates and their inhibitory effects on advanced glycation end products
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This study successfully established the feasibility of a two-step chemo-enzymatic synthesis of L-ascorbyl phenolates. Intermediate vinyl phenolates were first chemically produced and then underwent trans-esterification with L-ascorbic acid in the presence of Novozyme 435 (Candida Antarctica lipase B) as a catalyst. Twenty vinyl phenolates and 11 ascorbyl phenolates were subjected to in vitro bioassays to investigate their inhibitory activity against advanced glycation end products (AGEs). Among them, vinyl 4-hydroxycinnamate (17VP), vinyl 4-hydroxy-3-methoxycinnamate (18VP), vinyl 4-hydroxy-3,5-dimethoxycinnamate (20VP), ascorbyl 4-hydroxy-3-methoxycinnamate (18AP) and ascorbyl 3,4-dimethoxycinnamate (19AP) showed 2–10 times stronger inhibitory activities than positive control (aminoguanidine and its precursors). These results indicated that chemo-enzymatically synthesized compounds have AGE inhibitory effect and thus are effective in either preventing or retarding glycation protein formation.
- Hwang, Seung Hwan,Wang, Zhiqiang,Lim, Soon Sung
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p. 726 - 735
(2016/08/04)
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- COMPOUNDS FOR INHIBITING LIPID OXIDATION AND A METHOD FOR PRODUCING THE SAME
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The present invention relates to a compound for inhibiting lipid oxidation, and a producing method thereof. The compound for inhibiting lipid oxidation is synthesized by a transesterification reaction though a vinyl reaction and a lipase-catalyzed reaction. The produced compound for inhibiting lipid oxidation has an excellent effect of inhibiting oxidation according to a total oxidation value (TOTOX) which is a combination of a P-anisidine value (P-AnV) and a peroxide value (PV) and an analysis of a thiobarbituric acid reaction substance (TBARS).COPYRIGHT KIPO 2016
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Paragraph 0135-0136; 0143
(2017/05/03)
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- Donor specificity and regioselectivity in Lipolase mediated acylations of methyl α-d-glucopyranoside by vinyl esters of phenolic acids and their analogues
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Methyl α-d-glucopyranoside as a model acceptor was acylated by several phenolic and non-phenolic vinyl esters using immobilised Lipolase. Donor specificity and regioselectivity of reaction were investigated. Conversion and rate of acylation by structurally varied donors indicates that the synthetic reactivity of Lipolase corresponds to the hydrolytic activity of feruloyl esterase type A. Lipolase exhibited remarkable regioselectivity for primary position of methyl α-d-glucopyranoside. The acylation occurred exclusively at 6-O primary position when vinyl esters of phenolic acids (hydroxybenzoates, hydroxyphenylalkanoates and hydroxycinnamates) served as acyl donors (5-77%). In addition to the major 6-O-acyl products (52-79%), 2,6-di-O-acylated derivatives were isolated from reaction mixtures (2-13%) when non-phenolic donors were used (vinyl esters of fully methoxylated derivatives of phenolic acids, along with vinyl benzoates, cinnamates or some heterocyclic analogues).
- Mastihubova, Maria,Mastihuba, Vladimir
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supporting information
p. 5389 - 5392
(2013/09/23)
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- Copper(II)-catalyzed esterification of arenecarboxylic acids with aryl- and vinyl-substituted trimethoxysilanes
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In this paper, the copper(II)-catalyzed esterification reaction of arenecarboxylic acids with aryl- or vinyl-substituted trimethoxysilanes is described. A series of aryltrimethoxysilanes and arenecarboxylic acids worked well under this procedure, affording aryl benzoate derivatives in moderate to good yields. Notably, trimethoxy(vinyl)silanes also worked well under this procedure giving a facile and versatile method to access vinyl benzoate derivatives. Georg Thieme Verlag Stuttgart.
- Luo, Fang,Pan, Changduo,Qian, Pengcheng,Cheng, Jiang
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supporting information; experimental part
p. 2005 - 2010
(2010/08/19)
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- Au(I) complexes-catalyzed transfer vinylation of alcohols and carboxylic acids
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Au(I) complexes-catalyzed transfer vinylation of alcohols and carboxylic acids has been achieved. The catalyst system consists of 2 mol % AuClPPh3 and 2 mol % AgOAc. Primary alcohols and secondary alcohols were converted into corresponding vinyl ethers in good yield (64-93%); however, tertiary alcohols showed poor reactivities. Carboxylic acids were also transformed into corresponding vinyl esters in good yield (78-96%).
- Nakamura, Aki,Tokunaga, Makoto
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p. 3729 - 3732
(2008/09/20)
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- Synthesis of enol and vinyl esters catalyzed by an iridium complex
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Enol and vinyl esters were successfully synthesized by the use of an iridium complex as a catalyst. The reaction of carboxylic acid with terminal alkynes in the presence of catalytic amounts of [Ir(cod)Cl]2 and Na2CO3 gave the corresponding 1-alkenyl esters. The addition of carboxylic acids to alkynes principally took place in the Markovnikov fashion. In addition, by the use of an Ir complex combined with NaOAc various vinyl esters were prepared through the transvinylation between carboxylic acids and vinyl acetate.
- Nakagawa, Hideto,Okimoto, Yoshio,Sakaguchi, Satoshi,Ishii, Yasutaka
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p. 103 - 106
(2007/10/03)
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