848312-48-1Relevant articles and documents
Rhenium(I)-catalyzed intramolecular geminal carbofunctionalization of alkynes: Tandem cyclization of ω-acetylenic dienol silyl ethers
Kusama, Hiroyuki,Yamabe, Hokuto,Onizawa, Yuji,Hoshino, Takahiko,Iwasawa, Nobuharu
, p. 468 - 470 (2005)
(Chemical Equation Presented) Bicycle production: The low-valent rhenium complex [ReCl(CO)5] catalyzes a tandem intramolecular cyclization reaction of ω-acetylenic dienol silyl ethers. The alkyne undergoes a geminal carbofunctionalization in the presence of 0.5-3.0 mol % [ReCl(CO) 5] under photoirradiation to give bicyclic enol silyl ethers in high yields (see scheme, TIPS = triisopropylsilyl).
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
