64286-85-7Relevant academic research and scientific papers
Convenient and Simple Esterification in Continuous-Flow Systems using g-DMAP
Okuno, Yoshinori,Isomura, Shigeki,Sugamata, Anna,Tamahori, Kaoru,Fukuhara, Ami,Kashiwagi, Miyu,Kitagawa, Yuuichi,Kasai, Emiri,Takeda, Kazuyoshi
, p. 3587 - 3589 (2015/11/17)
The utility and applicability of polyethylene-g-polyacrylic acid-immobilized dimethylaminopyridine (g-DMAP) as a catalyst in a continuous-flow system were investigated for decarboxylative esterification. High catalytic activity toward acylation was provided by g-DMAP containing a flexible grafted-polymer structure. During decarboxylation, carboxylic acids and alcohols were converted cleanly using di-tert-butyl dicarbonate (Boc2O) as a coupling reagent, which reduced by-products. In addition, the use of Boc2O resulted in the formation of tert-butyl esters. These esterifications dramatically reduced the reaction time under continuous-flow conditions, with a residence time of approximately 2 min. This highly efficient esterification procedure will provide more practical industrial applications.
Dual Catalytic Decarboxylative Allylations of α-Amino Acids and Their Divergent Mechanisms
Lang, Simon B.,O'Nele, Kathryn M.,Douglas, Justin T.,Tunge, Jon A.
supporting information, p. 18589 - 18593 (2016/01/25)
The room temperature radical decarboxylative allylation of N-protected α-amino acids and esters has been accomplished via a combination of palladium and photoredox catalysis to provide homoallylic amines. Mechanistic investigations revealed that the stability of the α-amino radical, which is formed by decarboxylation, dictates the predominant reaction pathway between competing mechanisms.
Diastereoselective control of intramolecular aza-Michael reactions using achiral catalysts
Zhong, Cheng,Wang, Yikai,Hung, Alvin W.,Schreiber, Stuart L.,Young, Damian W.
supporting information; experimental part, p. 5556 - 5559 (2011/12/05)
An intramolecular aza-Michael reaction with a Cbz carbamate and an enone is reported to result in 3,5-disubstituted nitrogen-containing heterocycles. Either cis or trans isomers were obtained selectively using chiral substrates and an achiral Pd (II) comp
Versatile selective α-carboxylic acid esterification of N-protected amino acids and peptides by alcalase
Nuijens, Timo,Cusan, Claudia,Kruijtzer, John A. W.,Rijkers, Dirk T. S.,Liskamp, Rob M. J.,Quaedflieg, Peter J. L. M.
scheme or table, p. 809 - 814 (2009/07/11)
Under continuous removal of water, the industrial protease Alcalase allows selective synthesis of α-carboxylic acid methyl, ethyl, benzyl, allyl, 2-(trimethylsilyl)ethyl, and tert-butyl esters of amino acids and peptides under mild conditions in very high
A novel tert-butoxycarbonylation reagent: 1-tert-butoxy-2-tert-butoxycarbonyl-1,2-dihydroisoquinoline (BBDI)
Saito, Yukako,Ouchi, Hidekazu,Takahata, Hiroki
, p. 11599 - 11607 (2007/10/03)
The use of 1-tert-butoxy-2-tert-butoxycarbonyl-1,2-dihydroisoquinoline (BBDI) as a tert-butoxycarbonylation reagent for acidic proton-containing substrates such as phenols, aromatic and aliphatic amines hydrochlorides, and aromatic carboxylic acids in the absence of a base is described. The reactions proceed chemoselectively in high yield under mild conditions.
A novel 1-tert-butoxy-2-tert-butoxycarbonyl-1,2-dihydroisoquinoline (BBDI)-catalyzed esterification of N-protected amino acids with nearly equimolar amounts of alcohols in the presence of Boc2O
Saito, Yukako,Watanabe, Tomokazu,Takahata, Hiroki
, p. 3099 - 3102 (2007/10/03)
A very mild, BBDI-catalyzed esterification using approximately equimolar amounts of N-protected amino acids and alcohols, in junction with Boc2O is described.
Simple and mild esterification of N-protected amino acids with nearly equimolar amounts of alcohols using 1-tert-butoxy-2-tert-butoxycarbonyl-1,2- dihydroisoquinoline
Saito, Yukako,Yamaki, Toru,Kohashi, Fumiaki,Watanabe, Tomokazu,Ouchi, Hidekazu,Takahata, Hiroki
, p. 1277 - 1279 (2007/10/03)
A very mild, one-step esterification using nearly equimolar amounts of N-protected amino acids and alcohols, in conjunction with 1-tert-butoxy-2-tert- butoxycarbonyl-1,2-dihydroisoquinoline (BBDI) as a novel condensing reagent is described.
Dynamic Kinetic Resolution for Asymmetric Synthesis of α-Alkyl Amino Acids via Dual-Function Catalysis of Modified Cinchona Alkaloids
Hang, Jianfeng,Deng, Li
, p. 1927 - 1930 (2007/10/03)
The electronic property of the N-protecting group of N-carboxyanhydrides (NCA) is found to have a significant influence on the rate of racemization of NCA with modified cinchona alkaloids. Consequently, modified cinchona alkaloids can be applied as dual-function catalysts to catalyze both the racemization and alcoholytic kinetic resolution of alkyl NCA bearing an electron-withdrawing N-protecting group, leading to a dynamic kinetic resolution converting racemic alkyl NCAs to the corresponding amino esters in 59-75% ee and 75-87% yield. Upon recrystallization, the amino ester can be obtained in greater than 99% ee and 53% yield from the racemic NCA.
Photochemical protection of amines with Cbz and Fmoc groups
Helgen, Celine,Bochet, Christian G.
, p. 2483 - 2486 (2007/10/03)
The photochemical conversion of amines into carbamates was achieved using N-Cbz-, N-Fmoc-, and N-Boc-5,7-dinitroindolines. This reaction allows the protection of amines in neutral medium. Primary and unhindered secondary amines were protected to yield their benzyloxycarbonyl- and 9-fluorenylmethoxycarbonyl derivatives efficiently, whereas bulky amines or anilines gave low yields or no product. On the other hand, the formation of N-Boc compounds, although possible, proceeded only with low yields.
Development of a rapid, room-temperature dynamic kinetic resolution for efficient asymmetric synthesis of α-aryl amino acids
Hang, Jianfeng,Li, Hongming,Deng, Li
, p. 3321 - 3324 (2007/10/03)
equation presented A rapid, highly efficient and general dynamic kinetic resolution (DKR) of racemic α-aryl UNCAs with the dual-function catalysis of modified cinchona alkaloid was accomplished at room temperature. This DKR led to the development of a highly enantioselective catalytic method for the practical synthesis of a wide range of α-aryl and α-heteroaryl amino acids in 89-92% ee and 86-95% yield from racemic UNCAs.
