75078-91-0Relevant academic research and scientific papers
Olefin functionalization/isomerization enables stereoselective alkene synthesis
Gutierrez, Osvaldo,Koh, Ming Joo,Liu, Chen-Fei,Martin, Robert T.,Wang, Hongyu,Zhao, Haonan
, p. 674 - 683 (2021/08/06)
Despite tremendous efforts aimed at devising methods for stereoselective alkene synthesis, critical challenges are yet to be addressed. Direct access to a diverse range of 1-aryl(boryl)-1-methyl-functionalized tri- and tetrasubstituted trans alkenes, entities that are prevalent in many important molecules, through a catalytic manifold from readily available α-olefin substrates remains elusive. Here, we demonstrate that catalytic amounts of a non-precious N-heterocyclic carbene–Ni(I) complex in conjunction with a sterically bulky base promote site- and trans-selective union of monosubstituted olefins with a wide array of electrophilic reagents to deliver tri- and tetrasubstituted alkenes in up to 92% yield and >98% regio- and stereoselectivity. The protocol is amenable to the preparation of carbon- and heteroatom-substituted C=C bonds, providing distinct advantages over existing transformations. Utility is highlighted through concise stereoselective synthesis of biologically active compounds. [Figure not available: see fulltext.].
Synthesis of arotinoid acid and temarotene using mixed (Z)-1,2- bis(organylchalcogene)-1-alkene as precursor
Guerrero Jr., Palimécio G.,De Oliveira, Paulo R.,Baroni, Adriano C.M.,Marques, Francisco A.,Labes, Ricardo,Hurtado, Gabriela R.,Dabdoub, Miguel J.
, p. 5302 - 5305 (2012/11/13)
An efficient and novel total synthesis of the two bioactive retinoids temarotene and arotinoid acid (TTNPB) is described. The key steps in this process include the regio and stereoselective hydrotelluration of thioacetylene 9 and Te/Li transmetalation of mixed (Z)-1,2-bis(organylchalcogene)-1-alkene (Z)-3. The subsequent reaction involving the β-phenylthio vinyl lithiated intermediate 10 with dimethyl sulfate gave the (E)-vinyl sulfide 11. The Ni +2 cross-coupling of 11 with the corresponding phenylzinc bromide and p-oxazoline phenylzinc bromide 12 afforded the respective temarotene 2 and retinoid-oxazoline substituted 13. Finally, compound 13 was deprotected with HCl to furnish arotinoid acid (TTNPB) 1.
Highly regio- and stereoselective synthesis of alkenylboronic esters by copper-catalyzed boron additions to disubstituted alkynes
Kim, Hye Ryung,Yun, Jaesook
, p. 2943 - 2945 (2011/05/04)
The copper-catalyzed addition of bis(pinacolato)diboron to internal alkynes in the presence of methanol generates alkenylboron compounds with high levels of regio- and stereoselectivities. The catalytic efficiency is increased by using monodentate phosphine ligands, especially P(p-tolyl)3 and a range of internal alkynes was borylated in good yields. The Royal Society of Chemistry.
Arotinoids, a new class of highly active retinoids
Loeliger,Bollag,Mayer
, p. 9 - 15 (2007/10/02)
The synthesis and biological activity of new aromatic retinoids are reported. The most active ones belong to a chemical class of compounds, which we have termed 'arotinoids'. For the compound p-[(E)-2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthyl)-propenyl)]-benzoic acid ethyl ester, a therapeutic potency in the antipapilloma test was found which exceeds that of retinoic acid by a factor of 8000, while the concurrently observed toxic hypervitaminosis A effects are only increased by a factor of 800. The structural relationship of the arotinoids with retinoic acid is demonstrated; the arotinoids contain the retinoic acid carbon skeleton in a fixed cisoid geometric conformation.
