3588-57-6Relevant articles and documents
Chiral tetraaryl-and tetraalkynylborates as chiral solvating agents for tetraalkylammonium salts
Tayama, Eiji,Sugawara, Takeshi
supporting information, p. 803 - 811 (2019/01/18)
The application of tetracarbon-substituted chiral borate sodium salts (NaBR*4) as NMR chiral solvating agents for various tetraalkylammonium salts (R4NX) has been successfully demonstrated. Ion exchange between R4NX and NaBR*4 proceeded in excellent yields and provided the corresponding dia-stereomeric salts (R4NBR*4). The ee values of the R4NX salts were determined by1H NMR analysis of R4NBR*4. Two types of chiral borates, tetraaryl-and tetraalkynylborates with optically active 1,1′-binaphthyl components were used. At the beginning of this research, we investigated the efficacy of a known chiral tetraar-ylborate developed by Pommerening et al. for R4NX. To expand the possibility of further structural design of the chiral borate, we designed chiral tetraalkynylborates as a new structure. Their synthesis and application are also described.
Tertiary-butoxycarbonyl (Boc) – A strategic group for N-protection/deprotection in the synthesis of various natural/unnatural N-unprotected aminoacid cyanomethyl esters
Karmakar, Ananta,Basha, Mushkin,Venkatesh Babu,Botlagunta, Murali,Malik, Noormohamed Abdul,Rampulla, Richard,Mathur, Arvind,Gupta, Arun Kumar
, p. 4267 - 4271 (2018/11/03)
A number of cyanomethyl esters of natural/unnatural aminoacids with un-protected amino functionality were synthesized because of their synthetic and medicinal importance. Critical N-Boc deprotection methods in the presence of labile (hydrolytic sensitivity) cyanomethyl functionality were screened thoroughly and it was found that readily available 4M HCl in 1,4-dioxane solution (2–4 equiv); acetonitrile, 0 °C, 2–4 h was a suitable condition. This condition was generalized and successfully applied to a variety of alkyl, alkynyl, aryl, heteroaryl, benzyl, azido, spiro amino acid cyanomethylesters irrespective of the nature of the amine (primary or secondary) and the distance between the amine and ester group to achieve final deprotected amino esters with high yield, and purity compared to other commonly known N-protecting groups (Cbz, Fmoc, Ac, Bn, Bz etc.). It was also demonstrated that N-Boc protected aminoacid cyanomethylesters are stable enough to carry out further functionalization compared to N-unprotected counterparts.
Synthesis, screening and docking of small heterocycles as Glycogen Phosphorylase inhibitors
Schweiker, Stephanie S.,Loughlin, Wendy A.,Lohning, Anna S.,Petersson, Maria J.,Jenkins, Ian D.
, p. 584 - 594 (2015/03/14)
A series of morpholine substituted amino acids (phenylalanine, leucine, lysine and glutamic acid) was synthesized. A fragment-based screening approach was then used to evaluate a series of small heterocycles, including morpholine, oxazoline, dihydro-1,3-oxazine, tetrahydro-1,3-oxazepine, thiazoline, tetrahydro-1,3-pyrimidine, tetrahydro-1,3-diazepine and hexahydro-1H-benzimidazole, as potential inhibitors of Glycogen Phosphorylase a. Thiazoline 7 displayed an improved potency (IC50 of 25 μM) and had good LE and LELP values, as compared to heterocycles 1, 5, 9e13 and 19 (IC50 values of 1.1 mM e23.9 mM). A docking study using the crystal structure of human liver Glycogen Phosphorylase, provided insight into the interactions of heterocycles 5, 7, 9e13 and 19 with Glycogen Phosphorylase.
Synthesis of enantiopure free and N-benzyloxycarbonyl-protected 3-substituted homotaurines from naturally occurring amino acids
Zheng, Yongpeng,Xu, Jiaxi
, p. 5197 - 5206 (2014/12/10)
Enantiopure N-benzyloxycarbonyl-protected and free 3-substituted homotaurines were synthesized from naturally occurring amino acids via N-benzyloxycarbonyl protection, Arndt-Eistert homologation, reduction, esterification with thioacetic acid, and oxidation with performic acid. The current method is a convenient, practical, and salt-free method for the synthesis of enantiopure 3-substituted homotaurine with moderate to good yields.
Resolution of non-proteinogenic amino acids via microbial lipase-catalyzed enantioselective transesterification
Miyazawa, Toshifumi,Mio, Motoe,Watanabe, Yuko,Yamada, Takashi
, p. 219 - 224 (2008/09/20)
A number of non-proteinogenic amino acids bearing aliphatic side chains were resolved with moderate to good enantioselectivities (E = 15-42) through the Burkholderia cepacia lipase-catalyzed enantioselective transesterification of the 2,2,2-trifluoroethyl esters of their N-benzyloxycarbonyl derivatives with methanol as a nucleophile in diisopropyl ether.
Inhibitors interacting with the magnesium binding site of reverse transcriptase: Synthesis and biological activity studies of 3′-(Ω- amino-acyl) amino-3′-deoxy-thymidine
Goud, Thirumani Venkateshwar,Aubertin, Anne-Marie,Biellmann, Jean-Francois
, p. 495 - 505 (2008/09/21)
Active site of reverse transcriptase contains carboxylate groups involved in the magnesium binding. We prepared some nucleoside analogs which could bind to these carboxylates preventing the binding of nucleotides. To the 3′-amino-3′-deoxy-thymidine, different N-protected ω-amino-acids were bound, the protection removed to give the 3′-(ω-amino-acyl-) amino-3′-deoxy-thymidines in good yield. Some showed moderate to low activity in HIV 1 replication test. Copyright Taylor & Francis Group, LLC.
A Stereoselective entry into functionalized 1,2-diamines by zinc-mediated homologation of α-aminoacids
Hoang, Cam Thuy,Alezra, Valerie,Guillot, Regis,Kouklovsky, Cyrille
, p. 2521 - 2524 (2008/02/05)
A general, stereoselective synthsis of 4,5-disubstituted imidazolidines-2-ones from α-aminoacids has been developed: the key steps are a Biaise reaction of bromoacetate on α-aminonitriles and further reduction. Although reduction with sodium cyanoborohydride afforded a mixture of cis and trans isomers 6a-e with moderate to good stereoselectivity, reduction with sodium in liquid ammonia gave the trans isomers 8a-e with complete stereoselectivity. Acidic hydrolysis of the urea gave 4-amino-pyrrolidinones, which can be precursors to β,γ-diaminoacids or 3-aminopyrrolidines.
α-Chymotrypsin-catalyzed peptide synthesis in frozen aqueous solution using N-protected amino acid carbamoylmethyl esters as acyl donors
Salam, Sayed Mohiuddin Abdus,Kagawa, Ken-Ichi,Kawashiro, Katsuhiro
, p. 22 - 29 (2007/10/03)
A kinetically controlled peptide synthesis catalyzed by α-chymotrypsin was performed in frozen aqueous solution (ice, -24 °C). The yield of the peptide was significantly improved by the use of the carbamoylmethyl (Cam) ester as the acyl donor instead of the conventional ethyl ester. The peptide yield increased up to ca. 90% when N-benzyloxycarbonyl (CBZ)-Phe-OCam and H-Phe-NH2 were used as the acyl donor and nucleophile, respectively. Such an improvement of the peptide yield in ice was also observed in the coupling of other CBZ-amino acid Cam esters as acyl donors. Furthermore, this approach was applied to the synthesis of peptides containing d-amino acids. The peptides such as CBZ-d-Phe-Phe-NH2, CBZ-Phe-d-Phe-NH2 and CBZ-d-Phe-d-Phe-NH2 were also obtained in excellent to moderate yields in ice. A high diastereoselectivity towards the l-l peptide was observed when the racemic amino acid Cam ester was used as the acyl donor in ice.
Potassium trimethylsilanolate-mediated conversion of dialkyl phosphonates to their anhydrous potassium monoalkyl phosphonates under mild, non-aqueous conditions
Dziemidowicz, Joanna,Witt, Dariusz,Sliwka-Kaszynska, Magdalena,Rachon, Janusz
, p. 569 - 574 (2007/10/03)
Anhydrous potassium monoalkyl phosphonates have been prepared from the corresponding dialkyl phosphonates and potassium trimethylsilanolate under non-aqueous conditions in good to excellent yields. Simple workup procedure has been developed to afford high purity products.
The use of cellulose (chromatography paper) as a cheap, versatile and non-covalent support for organic molecules during multi-step synthesis
Shanahan, Stephen E.,Byrne, Douglas D.,Inglis, Graham G. A.,Alam, Mahbub,Macdonald, Simon J. F.
, p. 2554 - 2555 (2007/10/03)
Cellulose chromatography paper provides a novel non-covalent support for synthesis and in-situ purification of multi-dimensional arrays.
