نتایج جستجو برای: acetylenic diesters
تعداد نتایج: 1161 فیلتر نتایج به سال:
One-pot synthesis of substituted pyrroles by a cascade reaction of azides with Morita-Baylis-Hillman acetates of acetylenic aldehydes is described and the reaction is efficiently mediated by triphenyl phosphine at room temperature. Sodium azide is successfully used to provide N-unsubstituted pyrroles, while alkyl azides afforded the corresponding N-alkylated pyrroles through a sequence of allyl...
A novel metal-free approach to construct the tetrasubstituted furans from Morita-Baylis-Hillman (MBH)-carbonates of acetylenic aldehydes has been developed. This strategy involves the cascade nucleophilic substitution/5-exo-dig-cycloisomerization of MBH-carbonates with 1,3-dicarbonyl compounds to give uniquely substituted 2-furan-3-yl acrylates. Additionally, the obtained furan adducts open a n...
Acetylenic phosphaalkenes (APAs) are used as a novel type of ligands for the stabilization of gold nanoparticles (AuNP). As demonstrated by a variety of experimental and analytical methods, both structural features of the APA, that is, the P=C as well as the C≡C units are essential for NP stabilization. The presence of intact APAs on the AuNP is demonstrated by surface-enhanced Raman spectrosco...
Compounds incorporating the tetrathiafulvalene (TTF) donor unit and one or two cyanoethynylethene (CEE) acceptor units were prepared by Knoevenagel condensations of highly unstable, TTF-linked propargylic aldehyde or ketone derivatives. The resulting TTF-CEEs are very strong chromophores with low-energy end-absorptions beyond 900 nm. The molecules experience reversible oxidations of the TTF uni...
Enantioselective iodocycloetherifications can be conducted using sterically highly demanding BINOL-based phosphoric acid diesters as catalyst. To achieve enantioselective reactions, cocatalysis by triphenylphosphine selenide is necessary. With cocatalysis, good to excellent enantioselectivities achieved for a broad range of substrates catalyst and cocatalyst loadings low 1 mol %. The itself doe...
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