97682-96-7Relevant academic research and scientific papers
Efficient diastereoselective synthesis of a new class of azanucleosides: 2′-homoazanucleosides
Bouton, Jakob,Van Hecke, Kristof,Van Calenbergh, Serge
, p. 4307 - 4316 (2017/06/30)
Azanucleosides, sugar-modified nucleoside analogues containing a 4′ nitrogen atom, have shown a lot of therapeutic potential, e.g. as anti-cancer and antiviral agents. We report the synthesis of a series of 2’-homoazanucleosides, in which the nucleobase is attached to the 2’-position of the pyrrolidine ring via a methylene linker. A suitable orthogonally protected iminosugar was synthesized by ring closing metathesis and dihydroxylation as key steps and further converted to a series of 8 nucleoside analogues through Mitsunobu reaction with suitably protected nucleobases. The 5′ position of the adenine analogue was then further derivatized with thiols to afford 2 additional compounds. The final compounds were evaluated for biological activity.
Dual Palladium(II)/Tertiary Amine Catalysis for Asymmetric Regioselective Rearrangements of Allylic Carbamates
Bauer, Johannes Moritz,Frey, Wolfgang,Peters, René
supporting information, p. 5767 - 5777 (2016/04/20)
The streamlined catalytic access to enantiopure allylic amines as valuable precursors towards chiral β- and γ-aminoalcohols as well as α- and β-aminoacids is desirable for industrial purposes. In this article an enantioselective method is described that transforms achiral allylic alcohols and N-tosylisocyanate in a single step into highly enantioenriched N-tosyl protected allylic amines via an allylic carbamate intermediate. The latter is likely to undergo a cyclisation-induced [3,3]-rearrangement catalysed by a planar chiral pentaphenylferrocene palladacycle in cooperation with a tertiary amine base. The otherwise often indispensable activation of palladacycle catalysts by a silver salt is not required in the present case and there is also no need for an inert gas atmosphere. To further improve the synthetic value, the rearrangement was used to form dimethylaminosulfonyl-protected allylic amines, which can be deprotected under non-reductive conditions.
Total synthesis and configurational assignment of the marine natural product haliclamide
Pfeiffer, Bernhard,Speck-Gisler, Sandra,Barandun, Luzi,Senft, Ursula,De Groot, Claire,Lehmann, Irene,Ganci, Walter,Gertsch, Juerg,Altmann, Karl-Heinz
, p. 2553 - 2563 (2013/05/22)
The marine natural product haliclamide has been synthesized based on macrocyclization by ring-closing olefin metathesis. Using either enantiomer of two of the four building blocks that were employed to assemble the diene precursor for the metathesis reaction, three non-natural isomers of haliclamide were also prepared. On the basis of the comparison of the 1H and 13C NMR spectra of the individual stereoisomers with literature data for the natural product, the configuration of the previously unassigned stereocenters at C9 and C20 of haliclamide could be determined to be S for both carbons. The absolute configuration of haliclamide thus is 2S, 9S, 14R, 20S. The antiproliferative activity of synthetic haliclamide against several human cancer cell lines was found to be in the high μM range. The compound showed no antifungal or antibiotic activity.
Access to enantiomerically enriched cis-2,3-disubstituted azetidines via diastereoselective hydrozirconation
Pradhan, Tarun K.,Krishnan, K. Syam,Vasse, Jean-Luc,Szymoniak, Jan
supporting information; experimental part, p. 1793 - 1795 (2011/06/19)
An asymmetric variant of the hydrozirconation reaction has been established starting from Boc-protected chiral allylic amines. The resulting diastereoselectively formed N-functionalized organozirconiums can be considered as promising chirons. In this case
Synthesis of l-altro-1-deoxynojirimycin, d-allo-1-deoxynojirimycin, and d-galacto-1-deoxynojirimycin from a single chiral cyanohydrin
Van Den Nieuwendijk, Adrianus M. C. H.,Ruben, Mark,Engelsma, Sander E.,Risseeuw, Martijn D. P.,Van Den Berg, Richard J.B.H.N.,Boot, Rolf G.,Aerts, Johannes M.,Brussee, Johannes,Van Der Marel, Gijs A.,Overkleeft, Herman S.
supporting information; experimental part, p. 3957 - 3959 (2010/11/19)
The chemoenzymatic synthesis of three 1-deoxynojirimycin-type iminosugars is reported. Key steps in the synthetic scheme include a Dibal reduction-transimination-sodium borohydride reduction cascade of reactions on an enantiomerically pure cyanohydrin, itself prepared employing almond hydroxynitrile lyase (paHNL) as the common precursor. Ensuing ring-closing metathesis and Upjohn dihydroxylation afford the target compounds.
Unlocking ylide reactivity in the metal-catalyzed allylic substitution reaction: Stereospecific construction of primary allylic amines with aza-ylides
Evans, P. Andrew,Clizbe, Elizabeth A.
supporting information; experimental part, p. 8722 - 8723 (2009/12/04)
(Chemical Equation Presented) The transition metal catalyzed allylic amination represents a powerful and versatile cross-coupling for the asymmetric construction of stereogenic C-N bonds that are present in secondary metabolites and medicinally important
Synthesis of enantiomerically pure (+)- and (-)-protected 5-aminomethyl-1,3-oxazolidin-2-one derivatives from allylamine and carbon dioxide
Fernandez, Isabelle,Munoz, Luis
, p. 2548 - 2557 (2007/10/03)
The stereoselective synthesis of enantiomerically pure (5R)- and (5S)-aminomethyl-oxazolidinones with different protecting groups have been carried out from an allyl amine as the source of the carbon backbone. The key reaction is the high yield iodiocyclization of enantiomerically pure allylphenethyl amine in the presence of carbon dioxide.
Dynamic kinetic asymmetric transformation of diene monoepoxides: A practical asymmetric synthesis of vinylglycinol, vigabatrin, and ethambutol
Trost, Barry M.,Bunt, Richard C.,Lemoine, Remy C.,Calkins, Trevor L.
, p. 5968 - 5976 (2007/10/03)
The ability to perform a dynamic kinetic asymmetric transformation (DYKAT) using the palladium-catalyzed asymmetric allylic alkylation (AAA) is explored in the context of butadiene monoepoxide. The versatility of this commercially available, but racemic, four-carbon building block becomes significantly enhanced via conversion of both enantiomers into a single enantiomeric product. The concept is explored in the context of a synthesis of vinylglycinol with phthalimide as the nitrogen source. The success of the project required a new design of the ligand for palladium wherein additional conformational restraints were introduced. Thus, the phthalimide derivative of vinylglycinol was obtained in nearly quantitative yield and had an ee of 98% which, upon crystallization, was enhanced to > 99%. This one-step synthesis of a protected form of vinylglycinol provided short practical syntheses of the title compounds. Vigabatrin requires only four steps, and ethambutol six. The intermediate to the existing synthesis of ethambutol is available in 87% yield in three steps. (R)-Serine derives from oxidative cleavage of the double bond. The reaction of phthalimide and isoprene monoepoxide demonstrates the remarkable ability of the chiral ligands to control both regioselectivity and enantioselectivity and demonstrates the effectiveness of this protocol in creating a quaternary center asymmetrically.
