59086-52-1Relevant academic research and scientific papers
Overcoming the Deallylation Problem: Palladium(II)-Catalyzed Chemo-, Regio-, and Stereoselective Allylic Oxidation of Aryl Allyl Ether, Amine, and Amino Acids
Begam, Hasina Mamataj,Jana, Ranjan,Manna, Kartic,Samanta, Krishanu
supporting information, p. 7443 - 7449 (2020/10/09)
We report herein a Pd(II)/bis-sulfoxide-catalyzed intramolecular allylic C-H acetoxylation of aryl allyl ether, amine, and amino acids with the retention of a labile allyl moiety. Mechanistically, the reaction proceeds through a distinct double-bond isomerization from the allylic to the vinylic position followed by intramolecular carboxypalladation and the β-hydride elimination pathway. For the first time, C-H oxidation of N-allyl-protected amino acids to furnish five-membered heterocycles through 1,3-syn-addition is established with excellent diastereoselectivity.
Cobalt-catalyzed cyclization with the introduction of cyano, acyl and aminoalkyl groups
Hori, Hiroto,Arai, Shigeru,Nishida, Atsushi
, p. 4783 - 4788 (2019/05/24)
An efficient synthesis of carbo-and heterocycles using CC, CO and CN bonds under cobalt catalysis is described. The substituents on olefins are key for controlling the regio-and chemoselectivity in the initial hydrogen atom transfer step and quaternary carbons are efficiently constructed under mild conditions. Cyclopropane cleavage and tandem cyclization give highly functionalized bicyclic skeletons in a single operation.
Development of Macrocyclic Peptides Containing Epoxyketone with Oral Availability as Proteasome Inhibitors
Li, Daqiang,Zhang, Xiaotuan,Ma, Xiaodong,Xu, Lei,Yu, Jianjun,Gao, Lixin,Hu, Xiaobei,Zhang, Jiankang,Dong, Xiaowu,Li, Jia,Liu, Tao,Zhou, Yubo,Hu, Yongzhou
, p. 9177 - 9204 (2018/10/24)
Macrocyclization has been frequently utilized for optimizing peptide or peptidomimetic-based compounds. In an attempt to obtain potent, metabolically stable, and orally available proteasome inhibitors, 30 oprozomib-derived macrocyclic peptides with structural diversity in their N-terminus and linker were successively designed and synthesized for structure-activity relationship (SAR) studies. As a consequence, the macrocyclic peptides with N-methyl-pyrazole (24p, 24x), imidazole (24t), and pyrazole (24v) as their respective N-termini exhibited favorable in vitro activity and metabolic stability, which translated into their potent in vivo proteasome inhibitory activity after oral administration. In particular, compound 24v, as the most distinguished one among this series, displayed excellent chymotrypsin-like (ChT-L, β5) inhibitory potency (IC50 = 16 nM), low nanomolar antiproliferative activity against all three of the tested cell lines, and superior metabolic stability in mouse liver microsome (MLM), as well as favorable inhibition against ChT-L compared to that of oprozomib in BABL/c mice following po administration at a comparatively low dose, thereby representing a promising candidate for further development.
Repurposing a Library of Human Cathepsin L Ligands: Identification of Macrocyclic Lactams as Potent Rhodesain and Trypanosoma brucei Inhibitors
Giroud, Maude,Dietzel, Uwe,Anselm, Lilli,Banner, David,Kuglstatter, Andreas,Benz, J?rg,Blanc, Jean-Baptiste,Gaufreteau, Delphine,Liu, Haixia,Lin, Xianfeng,Stich, August,Kuhn, Bernd,Schuler, Franz,Kaiser, Marcel,Brun, Reto,Schirmeister, Tanja,Kisker, Caroline,Diederich, Fran?ois,Haap, Wolfgang
, p. 3350 - 3369 (2018/05/01)
Rhodesain (RD) is a parasitic, human cathepsin L (hCatL) like cysteine protease produced by Trypanosoma brucei (T. b.) species and a potential drug target for the treatment of human African trypanosomiasis (HAT). A library of hCatL inhibitors was screened, and macrocyclic lactams were identified as potent RD inhibitors (Ki 50 400 nM). SARs addressing the S2 and S3 pockets of RD were established. Three cocrystal structures with RD revealed a noncovalent binding mode of this ligand class due to oxidation of the catalytic Cys25 to a sulfenic acid (Cys-SOH) during crystallization. The P-glycoprotein efflux ratio was measured and the in vivo brain penetration in rats determined. When tested in vivo in acute HAT model, the compounds permitted up to 16.25 (vs 13.0 for untreated controls) mean days of survival.
Mild and versatile potassium fluoride/tetrabutylammonium fluoride protocol for ester hydrolysis
Vijayalakshmi,Balakrishna,Mustafa, Shaik
, p. 309 - 311 (2018/01/11)
A mild and versatile protocol of potassium fluoride/tetrabutylammonium fluoride (KF/TBAF) in aqueous tetrahydrofuran for ester hydrolysis has been developed. The method is applied on variety of aliphatic and aromatic ester moieties bearing acid or base sensitive functional groups. The conditions have been also applied on acetates to yield alcohols. The chirality of optically pure esters remained intact with the conditions of the reaction.
Organoselenium and DMAP co-catalysis: Regioselective synthesis of medium-sized halolactones and bromooxepanes from unactivated alkenes
Verma, Ajay,Jana, Sadhan,Prasad, Ch. Durga,Yadav, Abhimanyu,Kumar, Sangit
, p. 4179 - 4182 (2016/03/19)
A catalytic system consisting of bis(4-methoxyphenyl)selenide and 4-(dimethylamino)pyridine (DMAP) has been developed for the regioselective synthesis of medium-sized bromo/iodo lactones and bromooxepanes possessing high transannular strain. 77Se NMR, mass spectrometry and theoretical studies reveal that the reaction proceeds via a quaternary selenium intermediate.
Ring-closing metathesis reaction-based synthesis of new classes of polyether macrocyclic systems
Naveen,Babu, Srinivasarao Arulananda
, p. 7758 - 7781 (2015/09/08)
Ring closing metathesis (RCM) reactions of suitable substrates having terminal olefins, which are assembled from various linkers and hydroxy benzaldehydes and syntheses of a wide range of 16-30 membered, new crown ether-type polyether, aza-polyether, bis aza-polyether macrocycles and dilactone moiety embedded polyether macrocycles (macrolides) are reported. After the ring-closure reaction, installation of different functional groups and functional group modification on the periphery of the synthesized polyether/crown ether macrocycles obtained in the RCM reactions are accomplished using the epoxidation, oxidation and catalytic hydrogenation-based synthetic transformations. Along this line, the syntheses of a variety of polyether macrocycles possessing epoxide or α-hydroxy ketone or 1,2-diol functionalities at the periphery have been shown. Furthermore, the synthesized α-hydroxy ketone functionality installed polyether macrocycles were subjected to the allylation and Reformatsky type reactions to obtain homoallyl alcohol moiety-based and lactone ring-appended polyether macrocycles.
Oxidative cyclization of alkenoic acids promoted by AgOAc
Carrillo-Arcos, Ulises A.,Rojas-Ocampo, Jonathan,Porcel, Susana
, p. 479 - 483 (2016/01/09)
Alkenoic acids derived from salicylic acid and analogues undergo an unexpected oxidative cyclization process triggered by AgOAc leading to 4H-benzo[d][1,3]dioxin-4-ones. The process is affected by the substitution on the aryl and the allyl units.
Efficient medium ring size bromolactonization using a sulfur-based zwitterionic organocatalyst
Cheng, Yi An,Chen, Tao,Tan, Chong Kiat,Heng, Jun Jie,Yeung, Ying-Yeung
supporting information, p. 16492 - 16495,4 (2020/09/15)
Catalytic bromolactonization of long-chain olefinic acids resulting in the efficient synthesis of medium-sized lactones is reported using a zwitterionic catalyst and stoichiometric N-bromosuccinimide halogen source. The reaction was found to be more efficient at 0 °C than at room temperature, which could be attributed to the temperature dependence of the zwitterionic catalyst.
Facile synthesis of 2,3-dihydrobenzofuran-3-ylacetic acids by novel electrochemical sequential aryl radical cyclization-carboxylation of 2-allyloxybromobenzenes using methyl 4-tert-butylbenzoate as an electron-transfer mediator
Senboku, Hisanori,Michinishi, Jun-Ya,Hara, Shoji
supporting information; experimental part, p. 1567 - 1572 (2011/08/03)
Facile synthesis of 2,3-dihydrobenzofuran-3-ylacetic acids and related analogues was successfully carried out by a novel electrochemical aryl radical generation and its 5-exo cyclization followed by a carboxylation sequence of 2-allyloxybromobenzenes by u
