55207-76-6Relevant articles and documents
Evolution of a synthetic strategy for complex polypyrrole alkaloids: Total syntheses of curvulamine and curindolizine
Xuan, Jun,Haelsig, Karl T.,Sheremet, Michael,Machicao, Paulo A.,Maimone, Thomas J.
, p. 2970 - 2983 (2021)
Structurally unprecedented antibacterial alkaloids containing multiple electron-rich pyrrole units have recently been isolated from Curvularia sp. and Bipolaris maydis fungi. This article documents the evolution of a synthetic program aimed at accessing the flagship metabolites curvulamine and curindolizine which are presumably a dimer and trimer of a C10N biosynthetic building block, respectively. Starting with curvulamine, we detail several strategies to merge two simple, bioinspired fragments, which while ultimately unsuccessful, led us toward a pyrroloazepinone building block-based strategy and an improved synthesis of this 10π-aromatic heterocycle. A two-step annulation process was then designed to forge a conserved tetracyclic bis-pyrrole architecture and advanced into a variety of late-stage intermediates; unfortunately, however, a failed decarboxylation thwarted the total synthesis of curvulamine. By tailoring our annulation precursors, success was ultimately found through the use of a cyanohydrin nucleophile which enabled a 10-step total synthesis of curvulamine. Attempts were then made to realize a biomimetic coupling of curvulamine with an additional C10N fragment to arrive at curindolizine, the most complex family member. Although unproductive, we developed a 14-step total synthesis of this alkaloid through an abiotic coupling approach. Throughout this work, effort was made to harness and exploit the innate reactivity of the pyrrole nucleus, an objective which has uncovered many interesting findings in the chemistry of this reactive heterocycle.
FURO[3,4-B]PYRROLE-CONTAINING BTK INHIBITOR
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Paragraph 0083-0085, (2021/07/24)
The present application belongs to the field of pharmaceutical chemistry, and relates to a furo[3,4-b]pyrrole-containing BTK inhibitor, and in particular, to a compound of formula (I), a stereisomer or pharmacologically acceptable salt thereof, a preparation method therefor, a pharmaceutical composition containing the compound, and use thereof in treating BTK-related diseases.
CYCLIC MOLECULES AS BRUTON'S TYROSINE KINASE INHIBITOR
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Paragraph 0270-0272, (2021/11/26)
The present invention relates to a novel molecule with protein tyrosine kinase inhibitory activity, and the synthesis and usage thereof. Specifically, the present invention relates to compound by formula A, pharmaceutically acceptable salts, hydrates or solvates thereof, and the synthesis and usage thereof.
Chemodivergent Preparation of Various Heterocycles via Phase-Transfer Catalysis: Enantioselective Synthesis of Functionalized Piperidines
Bernardi, Luca,Bertuzzi, Giulio,Fochi, Mariafrancesca,Mazzanti, Andrea,Moimare, Pierluigi,Pecorari, Daniel,Silvestrini, Filippo
supporting information, (2020/02/11)
In this work, a new chemodivergent domino approach for the preparation of various saturated heterocycles, based on phase-transfer catalysis (PTC), is presented. The versatile nature of doubly electrophilic substrates, showing both a Michael acceptor and a ketone, tethered by a heteroatom, enables three different domino reaction pathways. The nucleophile dictates the chemoselectivity of the reaction. Sulfa-Michael/aldol, cyanide addition/oxa-Michael and Michael/H-shift/aldol processes, along with the variation of the tethering heteroatom, results in the formation of six different classes of saturated heterocycles. DFT calculations account for the observed chemo- and diastereoselectivity of the two most productive processes. Moreover, an extensive investigation on the sulfa-Michael/aldol pathway was carried out, ultimately leading to the development of a new enantioselective domino approach to multi-substituted piperidines based on PTC. (Figure presented.).
Asymmetric synthesis of propargylamines as amino acid surrogates in peptidomimetics
Wünsch, Matthias,Schr?der, David,Fr?hr, Tanja,Teichmann, Lisa,Hedwig, Sebastian,Janson, Nils,Belu, Clara,Simon, Jasmin,Heidemeyer, Shari,Holtkamp, Philipp,Rudlof, Jens,Klemme, Lennard,Hinzmann, Alessa,Neumann, Beate,Stammler, Hans-Georg,Sewald, Norbert
supporting information, p. 2428 - 2441 (2017/12/06)
The amide moiety of peptides can be replaced for example by a triazole moiety, which is considered to be bioisosteric. Therefore, the carbonyl moiety of an amino acid has to be replaced by an alkyne in order to provide a precursor of such peptidomimetics. As most amino acids have a chiral center at Cα, such amide bond surrogates need a chiral moiety. Here the asymmetric synthesis of a set of 24 N-sulfinyl propargylamines is presented. The condensation of various aldehydes with Ellman's chiral sulfinamide provides chiral N-sulfinylimines, which were reacted with (trimethylsilyl)ethynyllithium to afford diastereomerically pure N-sulfinyl propargylamines. Diverse functional groups present in the propargylic position resemble the side chain present at the Cα of amino acids. Whereas propargylamines with (cyclo)alkyl substituents can be prepared in a direct manner, residues with polar functional groups require suitable protective groups. The presence of particular functional groups in the side chain in some cases leads to remarkable side reactions of the alkyne moiety. Thus, electron-withdrawing substituents in the Cα-position facilitate a base induced rearrangement to α,β-unsaturated imines, while azide-substituted propargylamines form triazoles under surprisingly mild conditions. A panel of propargylamines bearing fluoro or chloro substituents, polar functional groups, or basic and acidic functional groups is accessible for the use as precursors of peptidomimetics.
Discovery of a series of efficient, centrally efficacious bace1 inhibitors through structure-based drug design
Butler, Christopher R.,Brodney, Michael A.,Beck, Elizabeth M.,Barreiro, Gabriela,Nolan, Charles E.,Pan, Feng,Vajdos, Felix,Parris, Kevin,Varghese, Alison H.,Helal, Christopher J.,Lira, Ricardo,Doran, Shawn D.,Riddell, David R.,Buzon, Leanne M.,Dutra, Jason K.,Martinez-Alsina, Luis A.,Ogilvie, Kevin,Murray, John C.,Young, Joseph M.,Atchison, Kevin,Robshaw, Ashley,Gonzales, Cathleen,Wang, Jinlong,Zhang, Yong,Oneill, Brian T.
, p. 2678 - 2702 (2015/04/14)
The identification of centrally efficacious β-secretase (BACE1) inhibitors for the treatment of Alzheimers disease (AD) has historically been thwarted by an inability to maintain alignment of potency, brain availability, and desired absorption, distribution, metabolism, and excretion (ADME) properties. In this paper, we describe a series of truncated, fused thioamidines that are efficiently selective in garnering BACE1 activity without simultaneously inhibiting the closely related cathepsin D or negatively impacting brain penetration and ADME alignment, as exemplified by 36. Upon oral administration, these inhibitors exhibit robust brain availability and are efficacious in lowering central Amyloid β (Aβ) levels in mouse and dog. In addition, chronic treatment in aged PS1/APP mice effects a decrease in the number and size of Aβ-derived plaques. Most importantly, evaluation of 36 in a 2-week exploratory toxicology study revealed no accumulation of autofluorescent material in retinal pigment epithelium or histology findings in the eye, issues observed with earlier BACE1 inhibitors.
Green and Efficient: Iron-Catalyzed Selective Oxidation of Olefins to Carbonyls with O2
Gonzalez-De-Castro, Angela,Xiao, Jianliang
supporting information, p. 8206 - 8218 (2015/07/15)
A mild and operationally simple iron-catalyzed protocol for the selective aerobic oxidation of aromatic olefins to carbonyl compounds is described. Catalyzed by a Fe(III) species bearing a pyridine bisimidazoline ligand at 1 atm of O2, α- and β-substituted styrenes were cleaved to afford benzaldehydes and aromatic ketones generally in high yields with excellent chemoselectivity and very good functional group tolerance, including those containing radical-sensitive groups. With α-halo-substituted styrenes, the oxidation took place with concomitant halide migration to afford α-halo acetophenones. Various observations have been made, pointing to a mechanism in which both molecular oxygen and the olefinic substrate coordinate to the iron center, leading to the formation of a dioxetane intermediate, which collapses to give the carbonyl product. (Chemical Equation).
Synthesis of a library of propargylated and PEGylated α-hydroxy acids toward "clickable" polylactides via hydrolysis of cyanohydrin derivatives
Zhang, Quanxuan,Ren, Hong,Baker, Gregory L.
, p. 9546 - 9555 (2015/02/19)
A new simple and practical protocol for scalable synthesis of a novel library of propargylated and PEGylated α-hydroxy acids toward the preparation of "clickable" polylactides was described. The overall synthesis starting from readily available propargyl alcohol, bromoacetaldehyde diethyl acetal, and OEGs or PEGs was developed as a convenient procedure with low cost and no need of column chromatographic purification. The terminal alkyne functionality survives from hydrolysis of the corresponding easily accessible cyanohydrin derivatives in methanolic sulfuric acid. Facile desymmetrization, monofunctionalization, and efficient chain-elongation coupling of OEGs further enable the incorporation of OEGs to α-hydroxy acids in a simple and efficient manner. At the end, synthesis of allyloxy lactic acid indicates that an alkene group is also compatible with the developed method. (Chemical Equation Presented).
Thiol-Ene click reactions - Versatile tools for the modification of unsaturated amino acids and peptides
Karmann, Lisa,Kazmaier, Uli
, p. 7101 - 7109 (2013/11/06)
Terminal γ,δ-unsaturated amino acids, easily available by Claisen rearrangement or palladium-catalysed allylic alkylation, are excellent substrates for radical thiol additions. These click reactions allow the introduction of highly functionalized side-chains into a given amino acid or peptide. This protocol is suitable for the modification of all kinds of terminal alkenes, such as allyl protecting groups. Terminal γ,δ-unsaturated amino acids and peptides, easily available by Claisen rearrangement or palladium-catalysed allylic alkylation, are excellent substrates for radical thiol additions. These click reactions allow the introduction of highly functionalized side-chains into a given amino acid or peptide. This protocol is also suitable for the modification of allyl protecting groups. Copyright
Model studies toward a synthesis of asperaculin A: Exploration of iterative intramolecular Pauson-Khand reaction based strategies to access the dioxa[5.5.5.6]fenestrane framework
Mehta, Goverdhan,Khan, Tabrez Babu
scheme or table, p. 4558 - 4561 (2012/09/25)
A concise strategy, involving tandem intramolecular Pauson-Khand reactions (IPKRs) on a readily available ene-diyne precursor, to access the dioxa-fenestrane framework is delineated.