137501-12-3Relevant academic research and scientific papers
Chemoenzymatic and Enantiomeric Switching Regimes Enabling the Synthesis of Homochiral Cyclohexa-2,5-dienones Incorporating All-Carbon Quaternary Centers
Ye, Sebastian,Banwell, Martin G.
, p. 15403 - 15412 (2021/10/25)
The enantiomerically pure, bromobenzene-derived metabolite 5 has been transformed into enone 20 using a reaction sequence involving Suzuki-Miyaura cross-coupling and Eschenmoser-Claisen rearrangement processes. Treatment of compound 20 with lithium hydroxide results in an acetonide fragmentation reaction that delivers the 4,4-disubstituted cyclohexa-2,5-dienone 21, reductive de-oxygenation of which leads to congener 22. A closely related sequence of reactions can be used to convert the same homochiral starting material 5 into compound ent-22.
Chemoenzymatic Synthesis of the Antifungal Compound (–)-Pestynol by a Convergent, Sonogashira Construction of the Central Yne-Diene
Borra, Suresh,Kumar, Manoj,McNulty, James,Baidilov, Daler,Hudlicky, Tomas
supporting information, p. 77 - 79 (2018/11/23)
A total synthesis of the fungal-derived natural product pestynol is reported via a convergent chemoenzymatic approach from the readily available precursors geranyl bromide, ethyl acetoacetate, trimethylsilylacetylene, and bromobenzene. Synthetic (–)-pestynol proved to be identical in all respects to the natural material, allowing confirmation of the structure including absolute stereochemistry.
Chemoenzymatic synthesis of hygromycin aminocyclitol moiety and its C2 epimer
Carrau, Gonzalo,Bellomo, Ana Inés,Suescun, Leopoldo,Gonzalez, David
, p. 788 - 802 (2019/01/08)
This manuscript describes the enantioselective synthesis of the aminocyclitol moiety of the antibiotic hygromycin A in eight steps and 39 % overall yield from a non-chiral starting material. The sequence made use of an initial enzymatic step to transfer chirality to an aromatic ring and was followed by selective organic chemistry transformations (oxidation, pro-tection, azidation, hydrolysis) of the six-membered ring in order to achieve the target. The approach is also amenable to the synthesis of other related unnatural analogues as exemplified by the synthesis of the C2 epimer of the natural aminocyclitol. All the intermediates were fully characterized, and the absolute stereochemistry assigned by spectrometric methods.
Synthesis of a Highly Functionalised and Homochiral 2-Iodocyclohexenone Related to the C-Ring of the Polycyclic, Indole Alkaloids Aspidophytine and Haplophytine
Dlugosch, Michael,Banwell, Martin G.
, p. 573 - 579 (2018/09/11)
The enzymatically-derived and enantiomerically pure (1S,2S)-3-bromocyclohexa-3,5-diene-1,2-diol (7) has been elaborated over 10 steps into cyclohexenone 8. The latter compound embodies the enantiomeric form of the C-ring associated with the hexacyclic framework of the alkaloid aspidophytine (2). As such, this work sets the stage for effecting the conversion of the enantiomeric metabolite ent-7 into compound ent-8, and thence, through previously established protocols, including a palladium-catalysed Ullmann cross-coupling reaction, into the title alkaloids.
The Synthesis of Certain Phomentrioloxin A Analogues and Their Evaluation as Herbicidal Agents
Taher, Ehab S.,Guest, Prue,Benton, Amanda,Ma, Xinghua,Banwell, Martin G.,Willis, Anthony C.,Seiser, Tobias,Newton, Trevor W.,Hutzler, Johannes
, p. 211 - 233 (2017/04/26)
A series of 28 analogues of the phytotoxic geranylcyclohexentriol (-)-phomentrioloxin A (1) has been synthesized through cross-couplings of various enantiomerically pure haloconduritols or certain deoxygenated derivatives with either terminal alkynes or borylated alkenes. Some of these analogues display modest herbicidal activities, and physiological profiling studies suggest that analogue 4 inhibits photosystem II in isolated thylakoids in vitro.
The Synthesis of Certain Derivatives and Analogues of (-)- and (+)-Galanthamine and an Assessment of their Capacities to Inhibit Acetylcholine Esterase
Buckler, Joshua N.,Taher, Ehab S.,Fraser, Nicolas J.,Willis, Anthony C.,Carr, Paul D.,Jackson, Colin J.,Banwell, Martin G.
, p. 7869 - 7886 (2017/08/14)
Syntheses of certain di- and mono-oxygenated derivatives (e.g., 2 and 3, respectively) and analogues (e.g., 4, a D-ring monoseco-analogue of 2) of both the (-)- and (+)-enantiomeric forms of the alkaloid galanthamine [(-)-1] are reported. All have been assessed for their capacities to inhibit acetylcholine esterase but, in contrast to the predictions from docking studies, none bind strongly to this enzyme.
A chemoenzymatic route to chiral siloxanes
Naoum, Ravi,Séguin, Jacqueline P.,Trant, John F.,Frampton, Mark B.,Hudlicky, Tomá?,Zelisko, Paul M.
, p. 4027 - 4031 (2016/07/06)
An approach employing two enzymes—toluene dioxygenase and immobilized lipase B from Candida antarctica (N435)—was explored as a potential biocatalytic method for the coupling of chiral diols with siloxane species. Analysis of reaction mixtures using1H NMR spectroscopy suggested that up to 66% consumption of the siloxane starting materials had occurred. Oligomeric species were observed and chiral products from the coupling of a cyclic diol with a siloxane molecule were isolated and characterized by MALDI-ToF MS and GPC. Immobilized lipases from Rhizomucor miehei and Thermomyces lanuginosus were also explored as potential catalysts for the coupling reactions, however, their use only returned starting material.
Chemoenzymatic total synthesis and reassignment of the absolute configuration of ribisin C
Lan, Ping,Banwell, Martin G.,Ward, Jas S.,Willis, Anthony C.
supporting information, p. 228 - 231 (2014/01/23)
The enantiomerically pure and enzymatically derived cis-1,2-dihydrocatechol 5 has been converted, by two related pathways, into compounds 3 and ent-3. As a result, it has been determined that the true structure of the natural product ribisin C is represen
Chemoenzymatic total syntheses of ribisins A, B, and D, polyoxygenated benzofuran derivatives displaying NGF-potentiating properties
Lan, Ping,Banwell, Martin G.,Willis, Anthony C.
, p. 2829 - 2842 (2014/05/06)
Total syntheses of the structures, 1, 2, and 4, assigned to the biologically active natural products ribisins A, B, and D, respectively, have been achieved using the microbially derived and enantiomerically pure cis-1,2-dihydrocatechol 5 as starting material. Key steps include Suzuki-Miyaura cross-coupling, intramolecular Mitsunobu, and tandem epoxidation/rearrangement reactions. As a result of these studies, the structures of ribisins A and D have been confirmed while that of congener B was shown to be represented by 31 rather than 2.
An efficient route for the synthesis of chiral conduritol-derivative carboxamides via palladium-catalyzed aminocarbonylation of bromocyclohexenetetraols
Carrilho, Rui M.B.,Heguaburu, Viviana,Schapiro, Valeria,Pandolfi, Enrique,Kollár, László,Pereira, Mariette M.
scheme or table, p. 6935 - 6940 (2012/08/29)
A family of chiral conduritol-derivative carboxamides was synthesized through palladium-catalyzed aminocarbonylation of diastereoisomeric bromocyclohexenetetraols, previously prepared through biotransformation of bromobenzene by mutant strains of Pseudomonas putida F39/D. The coupling reactions of bromocyclohexenetetraols with CO and different amines, such as tert-butylamine, aniline, and piperidine, were performed in the presence of in situ generated Pd(0)/PPh3 catalyst. The methodology was applied to the corresponding iodo-cyclohexenetetraol derivative, using (L)-alanine and (L)-valine methyl ethers as N-nucleophiles. The resulting carboxamides were obtained in highly chemoselective reactions, isolated, and fully characterized.
