Hypervalent Iodine(III)-Induced Intramolecular Cyclization of α-(Aryl)alkyl-β-dicarbonyl Compounds: A Convenient Synthesis of Benzannulated and Spirobenzannulated Compounds
摘要:
A novel hypervalent iodine(III)-induced direct intramolecular cyclization of alpha-(aryl)alkyl-beta -dicarbonyl compounds has been described. Both meta-and para-substituted phenol ether derivatives containing acyclic or cyclic 1,3-dicarbonyl moieties at the side chain undergo this reaction in a facile manner. The reactions afford benzannulated and spirobenzannulated compounds that are of biological importance. The reaction is found to be general, mild,: and high yielding. The mechanism: of the reaction has been shown to involve a cation radical intermediate.
New Intramolecular α-Arylation Strategy of Ketones by the Reaction of Silyl Enol Ethers to Photosensitized Electron Transfer Generated Arene Radical Cations: Construction of Benzannulated and Benzospiroannulated Compounds
摘要:
Efficient intramolecular alpha-arylation of ketones is achieved by the reaction of silyl enol ethers to photosensitized electron transfer (PET) generated arene radical cations. The arene radical cations are generated by one-electron transfer from the excited state of the methoxy-substituted arenes to ground-state 1,4-dicyanonaphthalene (DCN). This arylation strategy has provided the unique opportunity of constructing five- (23), six- (18), seven- (25) and eight-membered (27) benzannulated as well as benzospiroannulated (34) compounds. The explanation for the formation of 27 has been advanced by considering the proximity between the arene radical cation and silyl enol ether due to the self-coiling in the aqueous environment.
New Intramolecular α-Arylation Strategy of Ketones by the Reaction of Silyl Enol Ethers to Photosensitized Electron Transfer Generated Arene Radical Cations: Construction of Benzannulated and Benzospiroannulated Compounds
作者:Ganesh Pandey、M. Karthikeyan、A. Murugan
DOI:10.1021/jo9718612
日期:1998.5.1
Efficient intramolecular alpha-arylation of ketones is achieved by the reaction of silyl enol ethers to photosensitized electron transfer (PET) generated arene radical cations. The arene radical cations are generated by one-electron transfer from the excited state of the methoxy-substituted arenes to ground-state 1,4-dicyanonaphthalene (DCN). This arylation strategy has provided the unique opportunity of constructing five- (23), six- (18), seven- (25) and eight-membered (27) benzannulated as well as benzospiroannulated (34) compounds. The explanation for the formation of 27 has been advanced by considering the proximity between the arene radical cation and silyl enol ether due to the self-coiling in the aqueous environment.
Hypervalent Iodine(III)-Induced Intramolecular Cyclization of α-(Aryl)alkyl-β-dicarbonyl Compounds: A Convenient Synthesis of Benzannulated and Spirobenzannulated Compounds
作者:Mitsuhiro Arisawa、Namakkal G. Ramesh、Makiko Nakajima、Hirofumi Tohma、Yasuyuki Kita
DOI:10.1021/jo000953f
日期:2001.1.1
A novel hypervalent iodine(III)-induced direct intramolecular cyclization of alpha-(aryl)alkyl-beta -dicarbonyl compounds has been described. Both meta-and para-substituted phenol ether derivatives containing acyclic or cyclic 1,3-dicarbonyl moieties at the side chain undergo this reaction in a facile manner. The reactions afford benzannulated and spirobenzannulated compounds that are of biological importance. The reaction is found to be general, mild,: and high yielding. The mechanism: of the reaction has been shown to involve a cation radical intermediate.