Synthesis of halo-fluoro-substituted adamantanes by electrophilic transannular cyclization of bicyclo[3.3.1]nonane dienes
作者:Yurii A Serguchev、Maxim V Ponomarenko、Lyudmila F Lourie、Alexander N Chernega
DOI:10.1016/s0022-1139(03)00135-0
日期:2003.10
7-Dimethylenebicyclo[3.3.1]nonane and its derivatives with a methyl or phenyl substituent in a methylene group react, with N-halosuccinimides NXS (X=Cl, Br, I) in dichloromethane in the presence of tetrabutylammonium dihydrotrifluoride or polyfluorinated alcohols via a transannular cyclization leading to the corresponding 1-fluoro- or 1-polyfluoroalkoxy-3-halomethyladamantanes. The reaction of the dienes
The reactivity of propellane C−C bonds towards cerium(IV) ammonium nitrate (CAN) was studied utilizing photochemical initiation in acetonitrile. Synthetic as well as computational (B3LYP/6-311+G** and MP2/6-31G*) data strongly suggest that the activation of the C−C bonds in cyclopropane and cyclobutane derivatives involves NO3 radical attack on the hydrocarbon ring and does not proceed through single
Kinetic Isotope Effects for the C−H Activation Step in Phase-Transfer Halogenations of Alkanes
作者:Oliver Lauenstein、Andrey A. Fokin、Peter R. Schreiner
DOI:10.1021/ol0059347
日期:2000.7.1
of phase-transfer halogenations (Br and I) of alkanes, significant H/D kineticisotopeeffects (KIE = 4-5) indicate that hydrogen abstraction is rate limiting. The excellent agreement of computed and experimentally determined H/D KIE as well as trapping experiments support the involvement of trihalomethyl radicals in the activation step.
在烷烃的相转移卤化(Br和I)范围内,显着的H / D动力学同位素效应(KIE = 4-5)表明氢的提取是速率限制。计算和实验确定的H / D KIE以及捕获实验的极好的一致性支持了三卤甲基自由基参与活化步骤。
Experimental and theoretical studies on the transannular cyclizations of 3,7-dimethylenebicyclo[3.3.1]nonane with polyfluoroalkyl radicals
作者:Maxim V. Ponomarenko、Yurii A. Serguchev、Bogdan V. Ponomarenko、Gerd-Volker Röschenthaler、Andrey A. Fokin
DOI:10.1016/j.jfluchem.2006.03.006
日期:2006.7
Radical cyclizations of 3,7-dimethylenebicyclo[3.3.1]nonane with CF3I, n-C3F7I, ICF2COOEt and ICF2PO(OEt)2 selectively led to corresponding 3,7-noradamantanes, which were used for preparation of various polyfluoroalkyl substituted noradamantyl amines and carboxylates. DFT computations revealed that chemoselectivity of the radical cyclizations is realized due to the high electrophilicity of the CF3
Elemental F<sub>2</sub>with Transannular Dienes: Regioselectivities and Mechanisms
作者:Maxim V. Ponomarenko、Yuriy A. Serguchev、Markus E. Hirschberg、Gerd-Volker Röschenthaler、Andrey A. Fokin
DOI:10.1002/chem.201402640
日期:2014.8.11
Three reaction paths, namely, molecule‐induced homolytic, free radical, and electrophilic, were modeled computationally at the MP2 level of ab initio theory and studied experimentally for the reaction of F2 with the terminal dienes of bicyclo[3.3.1]nonane series. The addition of fluorine is accompanied by transannular cyclization to the adamantane derivatives in which strong evidence for the electrophilic