scholarly journals Catalytic Z-Selective Cross-Metathesis in Complex Molecule Synthesis: A Convergent Stereoselective Route to Disorazole C1

2014 ◽  
Vol 136 (46) ◽  
pp. 16136-16139 ◽  
Author(s):  
Alexander W. H. Speed ◽  
Tyler J. Mann ◽  
Robert V. O’Brien ◽  
Richard R. Schrock ◽  
Amir H. Hoveyda
Keyword(s):  
Complex Molecule ◽  
Cross Metathesis ◽  
Disorazole C1

ChemInform Abstract: Catalytic Z-Selective Cross-Metathesis in Complex Molecule Synthesis: A Convergent Stereoselective Route to Disorazole C1.

ChemInform ◽  
2015 ◽  
Vol 46 (21) ◽  
pp. no-no
Author(s):  
Alexander W. H. Speed ◽  
Tyler J. Mann ◽  
Robert V. O'Brien ◽  
Richard R. Schrock ◽  
Amir H. Hoveyda
Keyword(s):  
Complex Molecule ◽  
Cross Metathesis ◽  
Disorazole C1

The Hoveyda Synthesis of Disorazole C1

2017 ◽  
Author(s):  
Douglass F. Taber
Keyword(s):  
Anticancer Activity ◽  
Vinyl Acetate ◽  
Secondary Alcohol ◽  
Butyl Ester ◽  
Geometric Isomer ◽  
Allylic Alcohol ◽  
Starting Material ◽  
Boston College ◽  
Cross Metathesis ◽  
Disorazole C1

Disorazole C1 3, isolated from fermentation of the myxobacterium Sorangium cellu­losum, shows antifungal and anticancer activity. Amir H. Hoveyda of Boston College applied (J. Am. Chem. Soc. 2014, 136, 16136) recent advances in alkene metathesis from his group to enable the efficient assembly of 2 and so of 3. The ester 1 was assembled from the alcohol 11 and the acid 18. The preparation of 11 began with the enantioselective addition of 5 to 4 to give 6 and then 7, as described by Kalesse (Angew. Chem. Int. Ed. 2010, 49, 1619). Leighton allylation led to 8, that was then coupled with 9 to give 10 with high Z selectivity. Iodination of 10 followed by deprotection then completed the assembly of 11. The starting material for the acid 18 was the allylic alcohol 13. As reported by Cramer (Angew. Chem. Int. Ed. 2008, 47, 6483), exposure of the racemic alcohol 12 to vinyl acetate in the presence of Amano lipase PS converted one enantiomer to the acetate, leaving 13. Methylation of the secondary alcohol followed by acid-mediated removal of the t-butyl ester led to the acid 14, that was converted to the correspond­ing acyl fluoride and coupled with serine Me ester 15 to give 16. After cyclization to the oxazole 17, cross metathesis with five equivalents of 4-bromo-1-butene gave the homoallylic bromide, that was readily eliminated with DBU to give, after saponifica­tion, the acid 18. The cross metathesis of the coupled ester 1, a polyene, with 9 proceeded with remarkable selectivity to give 2, again as the Z geometric isomer. On exposure to the Heck catalyst Pd [(o-tolyl)3P]2, 2 dimerized efficiently. The deprotection was not straightforward, but conditions (H2SiF6, CH3OH, 4°C, 72 h) were found that deliv­ered 3 in 68% yield.

Endgroup and Sidechain Functionalization of Surface-Initiated ROMP Thin Films: Progress Towards ROMP-Based Molecular Wires

2018 ◽  
Author(s):  
Nicholas Marshall
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Cyclic Voltammetry ◽  
Polymer Films ◽  
Conjugated Polymer ◽  
Ring Opening ◽  
Molecular Wires ◽  
Metathesis Polymerization ◽  
Cross Metathesis ◽  
Active Ester

A set of experiments in surface-initiated ring-opening metathesis polymerization, including end-functionalization of growing brushes and contact angle/cyclic voltammetry measurements. We report preparation and CV of two different conjugated polymer films, and several endgroup and sidechain functionalization experiments using cross-metathesis and active ester substitution.<br>

A One-Pot Chemoenzymatic Synthesis of (2S,4R)-4-Methylproline Enables the First Total Synthesis of Antiviral Lipopeptide Cavinafungin B

2018 ◽  
Author(s):  
Christian R. Zwick ◽  
Hans Renata
Keyword(s):  
Total Synthesis ◽  
Natural Product ◽  
Complex Molecule ◽  
Molecular Target ◽  
Chemoenzymatic Synthesis ◽  
General Strategy ◽  
One Pot

We report an efficient ten-step synthesis of antiviral natural product cavinafungin B in 37% overall yield. By leveraging a one-pot chemoenzymatic synthesis of (2S,4R)-4-methylproline and oxazolidine-tethered (Rink-Boc-ATG-resin) SPPS methodology, the assembly of our molecular target could be conducted in an efficient manner.This general strategy could prove amenable to the construction of other natural and unnatural linear lipopeptides. The value of incorporating biocatalytic steps in complex molecule synthesis is highlighted by this work.

Synthesis of Conjugated Triynes via Alkyne Metathesis

2019 ◽  
Author(s):  
Idriss Curbet ◽  
Sophie Colombel-Rouen ◽  
Romane Manguin ◽  
Anthony Clermont ◽  
Alexandre Quelhas ◽  
...  
Keyword(s):  
Steric Hindrance ◽  
High Selectivity ◽  
Alkyne Metathesis ◽  
Cross Metathesis ◽  
Synthetic Strategy ◽  
Sterically Hindered ◽  
Site Selective

<div> <div> <div> <div> <p>The synthesis of conjugated triynes by molybdenum-catalyzed alkyne metathesis is reported. Strategic to the success of this approach is the utilization of sterically-hindered diynes that allowed for the site- selective alkyne metathesis to produce the desired con- jugated triyne products. The steric hindrance of alkyne moiety was found to be crucial in preventing the for- mation of diyne byproducts. This novel synthetic strategy was amenable to self- and cross-metathesis providing straightforward access to the corresponding symmetrical and dissymmetrical triynes with high selectivity. </p> </div> </div> </div> </div>

Concise Total Synthesis of Curvulone B

Synlett ◽  
2020 ◽  
Author(s):  
Debendra K. Mohapatra ◽  
Shivalal Banoth ◽  
Utkal Mani Choudhury ◽  
Kanakaraju Marumudi ◽  
Ajit C. Kunwar
Keyword(s):  
Total Synthesis ◽  
Stereoselective Synthesis ◽  
Ring System ◽  
Bond Forming ◽  
Cross Metathesis ◽  
Bond Forming Reactions ◽  
Key Steps

AbstractA concise and convergent stereoselective synthesis of curvulone B is described. The synthesis utilized a tandem isomerization followed by C–O and C–C bond-forming reactions following Mukaiyama-type aldol conditions for the construction of the trans-2,6-disubstituted dihydropyran ring system as the key steps. Other important features of this synthesis are a cross-metathesis, epimerization, and Friedel–Crafts acylation.

scholarly journals Conversion of Dinitrogen into Nitrile: Cross Metathesis of N2‐Derived Molybdenum Nitride with Alkynes

2021 ◽  
Author(s):  
Jinyi Song ◽  
Qian LIAO ◽  
Xin Hong ◽  
Li Jin ◽  
Nicolas Mézailles
Keyword(s):  
Molybdenum Nitride ◽  
Cross Metathesis

Facile fluorination of nitrile-butadiene rubber via olefin cross metathesis

Polymer ◽  
2021 ◽  
Vol 217 ◽  
pp. 123455
Author(s):  
Qiang Gui ◽  
Changou Pan ◽  
Siwei Shen ◽  
Pengwei Xie ◽  
Mingliang Pei ◽  
...  
Keyword(s):  
Butadiene Rubber ◽  
Cross Metathesis ◽  
Nitrile Butadiene Rubber
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