Xi,Xn:;113439-83-1Relevant articles and documents
Gold-Catalyzed Regioselective Oxyfluorination/Oxydifluorination vs. Diketonization of Phthalimido-Protected Propargylamines with Selectfluor
Arcadi, Antonio,Marsicano, Vincenzo,Michelet, Véronique
supporting information, (2022/01/22)
Alkyl- and aryl-substituted N-propargyl phthalimides were used as valuable building blocks for the selective formation of the corresponding α-fluoro, β-phthalimido ketones, α,α-difluoro, β-phthalimido ketones or β-phthalimido α-diketones by means of gold-catalyzed oxyfluorination/oxydifluorination or dioxygenation reactions. The key factors addressing the product selectivity control were determined. The simultaneous assembly of the quinoxaline nucleus and the removal of the phthalimido-protecting group were tested. Reaction mechanisms of the different reaction pathways are assumed.
Experimental and computational evidence on gold-catalyzed regioselective hydration of phthalimido-protected propargylamines: An entry to β-amino ketones
Arcadi, Antonio,Aschi, Massimiliano,Marsicano, Vincenzo,Michelet, Véronique
supporting information, p. 9438 - 9447 (2020/12/15)
The results of our investigations on the Au-catalyzed regioselective hydration reaction of both alkyl- A nd aryl-substituted N-propargyl phthalimides directed to the selective formation of the corresponding β-phthalimido ketones are described. Experimental data, in particular the observed regioselectivity, have been qualitatively supported by quantum-chemical calculations carried out on model systems in the framework of Density Functional Theory (DFT) followed by quantum theory of atoms in molecules (QTAIMS). Our results suggest that the electronic features of the initial adduct between the propargyl triple bond and the Au(i) catalyst, in particular the character of the gold-triple bond interaction, are essential for the observed regioselectivity. Other effects, such as the presence of the solvent and the formation of a H-bond between the water molecule and the phthalimido moiety, although apparently irrelevant for the regioselectivity, have proven to be kinetically and catalytically rather important. This journal is
Tungsten(0)- and rhenium(I)-catalyzed tandem cyclization of acetylenic dienol silyl ethers based on geminal carbo-functionalization of alkynes
Kusama, Hiroyuki,Karibe, Yusuke,Imai, Rie,Onizawa, Yuji,Yamabe, Hokuto,Iwasawa, Nobuharu
supporting information; experimental part, p. 4839 - 4848 (2011/06/21)
Tungsten(0)- and rhenium(I)-catalyzed reactions of acetylenic dienol silyl ethers based on the concept of geminal carbo-functionalization of alkynes are reported. Treatment of 3-siloxy-1,3-diene-7-ynes with catalytic amounts of [W(CO)6] or [ReCl(CO)5] under photoirradiation conditions gives synthetically useful bicyclo[3.3.0]octane derivatives in good yields. Extremely high catalytic activity is noted for the rhenium(I) complex. The reaction has been extended to substrates containing a nitrogen atom in their tethers. In this case, two kinds of synthetically useful heterocyclic compounds-the 2-azabicyclo[3.3.0]octane derivatives 9 and the monocyclic dihydropyrroles 10, with allenyl substituents-are obtained, and selective preparation of either product can be achieved through the use of an appropriate combination of the nitrogen substituent and the type of the rhenium(I) catalyst. The 2-azabicyclo[3.3.0]octane derivatives 9 are obtained selectively by carrying out treatment of N-Ns derivatives in the presence of [ReCl(CO) 4(PPh3)], whereas the dihydropyrrole derivatives 10 are obtained by treatment of N-Mbs derivatives with [ReCl(CO)5]/ AgSbF6. Finally, we have applied this geminal carbo-functionalization to one-carbon-elongated substrates containing N-Ts moieties in their tethers. Selective 5-exo cyclization is achieved in the presence of gold(I) or rhenium(I) catalysts, whereas 6-endo cyclization is observed on use of [W(CO) 6]. Geminal carbo-functionalization of 3-siloxy-1,3-dien-7-ynes leading to bicyclo[3.3.0]octane derivatives is achieved through electrophilic activation of alkynes by tungsten(0) and rhenium(I) catalysts (see graphic). Extremely high activity is noted for rhenium(I) catalysts. Furthermore, selective preparation of two different classes of heterocyclic compounds from 5-aza-3-siloxy-1,3-dien-7-ynes is also achieved by appropriate choice of the rhenium(I) catalyst and the protecting group on the nitrogen. Copyright
