ChemInform Abstract: Enantioselective Synthesis of Propargyl Alcohols as Multifunctional Synthons

ChemInform ◽  
2008 ◽  
Vol 39 (48) ◽  
Author(s):  
J. S. Yadav ◽  
S. Chandrasekhar
2019 ◽  
Author(s):  
Prianka Chohan ◽  
Giovanni Barrera ◽  
Kimberly Valdivia ◽  
Parminder Kaur

<div>A novel titanium/proline-derived catalyst system is reported for the enantioselective synthesis of propargyl alcohols. The reaction proceeded smoothly under mild conditions with efficient reaction times. A series of proline and proline-based ligands including Lproline, L-prolinol, trans-hydroxy-L-prolinol, and substituted trans hydroxy-L-proline derivatives were used to have a better stereocontrol on the reaction. Initially, lithium acetylide was employed to carry out the nucleophilic addition reaction, however poor reaction profile was achieved with poor enantioselectivities. When diethylzinc was used instead, high product yields (>85%) and moderate to high enantioselectivities were achieved (68-82%). Three different alkynes, aromatic as well as aliphatic, phenylacetylene, n-hexyne and 3,3-diethoxy-prop-1-yne were used to carry out the reaction with a series of different aromatic and heterocyclic aldehydes. Better reaction profiles were achieved with aromatic alkynes than with aliphatic ones.</div>


2019 ◽  
Author(s):  
Prianka Chohan ◽  
Giovanni Barrera ◽  
Kimberly Valdivia ◽  
Parminder Kaur

<div>A novel titanium/proline-derived catalyst system is reported for the enantioselective synthesis of propargyl alcohols. The reaction proceeded smoothly under mild conditions with efficient reaction times. A series of proline and proline-based ligands including Lproline, L-prolinol, trans-hydroxy-L-prolinol, and substituted trans hydroxy-L-proline derivatives were used to have a better stereocontrol on the reaction. Initially, lithium acetylide was employed to carry out the nucleophilic addition reaction, however poor reaction profile was achieved with poor enantioselectivities. When diethylzinc was used instead, high product yields (>85%) and moderate to high enantioselectivities were achieved (68-82%). Three different alkynes, aromatic as well as aliphatic, phenylacetylene, n-hexyne and 3,3-diethoxy-prop-1-yne were used to carry out the reaction with a series of different aromatic and heterocyclic aldehydes. Better reaction profiles were achieved with aromatic alkynes than with aliphatic ones.</div>


ChemInform ◽  
2010 ◽  
Vol 24 (28) ◽  
pp. no-no
Author(s):  
R. C. HARTLEY ◽  
S. LAMOTHE ◽  
T. H. CHAN

1993 ◽  
Vol 34 (9) ◽  
pp. 1449-1452 ◽  
Author(s):  
R.C. Hartley ◽  
S. Lamothe ◽  
T.H. Chan

Author(s):  
Xin-Ming Xu ◽  
Ming Xie ◽  
Jiazhu Li ◽  
Mei-Xiang Wang

An exquisite Pybox/Cu(OTf)2-catalyzed asymmetric tandem reaction of tertiary enamides was developed, which enabled the expeditious synthesis of indolizino[8,7-b]indole derivatives in high yield, excellent enantioselectivity and diastereoselectivity.


2018 ◽  
Author(s):  
Matthew L. Landry ◽  
Grace McKenna ◽  
Noah Burns

A concise and selective synthesis of the dichlorinated meroterpenoid azamerone is described. The paucity of tactics for the synthesis of chiral organochlorides motivated the development of unique strategies for accessing these motifs in enantioenriched forms. The route features a novel enantioselective chloroetherification reaction, a Pd-catalyzed cross-coupling between a quinone diazide and a boronic hemiester, and a late-stage tetrazine [4+2]-cycloaddition/oxidation cascade.


2019 ◽  
Author(s):  
Ming Shang ◽  
Karla S. Feu ◽  
Julien C. Vantourout ◽  
Lisa M. Barton ◽  
Heather L. Osswald ◽  
...  

<div> <div> <div> <p>The union of two powerful transformations, directed C–H activation and decarboxylative cross-coupling, for the enantioselective synthesis of vicinally functionalized alkyl, carbocyclic, and heterocyclic compounds is described. Starting from simple carboxylic acid building blocks, this modular sequence exploits the residual directing group to access more than 50 scaffolds that would be otherwise extremely difficult to prepare. The tactical use of these two transformations accomplishes a formal vicinal difunctionalization of carbon centers in a way that is modular and thus amenable to rapid diversity incorporation. A simplification of routes to known preclinical drug candidates is presented along with the rapid diversification of an antimalarial compound series. </p> </div> </div> </div>


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