177481-88-8Relevant academic research and scientific papers
An Unusual Conversion of 2-(Alkynonyl)Alkynylbenzenes to Isocoumarins by a Retro-Favorskii-like Degradation
Santhi, Jampani,Baire, Beeraiah
supporting information, p. 3161 - 3165 (2019/09/17)
We report the discovery of an anomalous reaction of 2-(alkynonyl)alkynylbenzenes under AgI catalysis for the selective formation of isocoumarins. This reaction is previously undocumented for 2-(alkynonyl)alkynylbenzenes in terms of the reaction mechanism and the product formed. Water (H2O18) labeling studies suggested a possible mechanistic pathway in which the initial formation of a pyrylium ion is followed by hydrative dealkynylation, that is, water incorporation and alkyne expulsion, similar to a retro-Favorskii reaction.
Base-Catalyzed Cyclization of 1,6-Diynyl Carboxylates Involving Propargyl-Allenyl Isomerization: Efficient Synthesis of Benzo[b]fluorene and Its Analogues
Sun, Ning,Xie, Xin,Wang, Gaonan,Chen, Haoyi,Liu, Yuanhong
supporting information, p. 1394 - 1401 (2017/04/21)
An efficient protocol for the synthesis of benzo[b]fluorenes via base-catalyzed cyclization of 1,6-diynyl carbonates, esters or ethers has been developed. The reaction likely proceeds via base-induced propargyl-allenyl isomerization followed by Schmittel-type cyclization. Heterocycle-fused fluorenes such as thiophene- or pyridine-fused substrates could also be conveniently constructed by this method. The synthetic utility of this reaction was demonstrated by the preparation of up to seven-ring fused polycyclic aromatic hydrocarbons. (Figure presented.).
Gold-catalyzed Intermolecular Oxidations of 2-Ketonyl-1-ethynyl Benzenes with N-Hydoxyanilines to Yield 2-Aminoindenones via Gold Carbene Intermediates
Mokar, Bhanudas Dattatray,Huple, Deepak B.,Liu, Rai-Shung
, p. 11892 - 11896 (2016/11/16)
Gold-catalyzed oxidations of 2-ketonyl-1-ethynyl benzenes with N-hydroxyanilines yield 2-aminoindenone derivatives efficiently. Experimental data suggests that this process involves an α-oxo gold carbene intermediate, generated from the attack of N-hydroxyaniline on furylgold carbene intermediate, rather than the typical attack of oxidants on π-alkynes.
Parallel mechanisms for the cycloaromatization of enyne allenes
Hughes, Thomas S.,Carpenter, Barry K.
, p. 2291 - 2298 (2007/10/03)
The Myers-Saito cycloaromatization of enyne allenes is proposed to consist of two parallel mechanisms, one involving a biradical and the other with dipolar character. MCSCF calculations suggest that a nonplanar cyclic allene could be fairly close in enthalpy to the biradical, while the planar zwitterion originally proposed as a possible second intermediate is in fact a transition state for the interconversion of the two enantiomeric cyclic allenes. Competitive trapping experiments rule out the presence of a single intermediate and are consistent with the participation of parallel pathways. The reaction of (Z)-hepta-1,2,4-trien-6-yne in cyclopentadiene gave an inseparable mixture of two tetracyclic products whose structures were elucidated with 2-D NMR.
Synthesis of 5-/10-membered ring analogues of the dienediyne core of neocarzinostatine chromophore by palladium(0)-mediated ring-closure reaction
Suffert, Jean,Abraham, Estelle,Raeppel, Stephane,Brueckner, Reinhard
, p. 447 - 456 (2007/10/03)
The new dienediynes 5, 6, and 7 were synthesised from a monoprotected diyne and an already described bis(enol triflate) 4 derived from formylcyclopentanone. When 5 and 6 were subjected to nucleophilic attack by a thiol, cycloaromatisation occurred, and the phenanthrenes 23a and 23b were obtained in 30 and 42% yield, respectively. VCH Verlagsgesellschaft mbH, 1996.
