We achieved intra- and intermolecular C(sp3)–H alkoxylation of benzylic positions of heteroaromaticcompounds using CuBrn (n = 1, 2)/5,6-dimethylphenanthroline (or 4,7-dimethoxyphenanthroline) and (tBuO)2 as a catalyst and an oxidant, respectively. The reaction proceeded at both terminal and internal benzylic positions of the alkyl groups. The intramolecular alkoxylation was performed on a gram scale
Novel Synthesis of 1,3-Disubstituted Alkyl- and Aralkylnaphthalenes from Methylenetriphenylphosphorane, 1,1-Disubstituted Epoxides, Paraformaldehyde, and Trimethylsilyl Triflate
作者:Kentaro Okuma、Yoshitaka Hirose、Kosei Shioji
DOI:10.1246/cl.2002.438
日期:2002.4
A novel approach toward the synthesis of 3-methylnaphthalenes is achieved by the reaction of 3-methylene-5,5-disubstituted tetrahydrofurans derived from methylenetriphenylphosphorane, 1,1-disubstituted epoxides and paraformaldehyde with trimethylsilyl trifluoromethanesulfonate in the presence of diisopropylethylamine.
useful functional groups. In this study, we disclose a non-halide-mediated electrochemical epoxidation of alkenes to form epoxides using water as an oxygen source. This method catalyzed by (TMP)MnCl (TMP = tetramesitylporphyrin) exhibits remarkable efficiency, enabling the epoxidation of both aromatic and aliphaticalkenes with excellent faradaic efficiencies (up to 89%). Preliminary mechanistic studies
applicability. Herein, we report an efficient PPh3-promoted metal-free strategy for deoxygenation of epoxides to generate alkene derivatives. The success of deoxyalkenylation of epoxides bearing a wide range of functional groups to give terminal, 1,1-disubstituted, and 1,2-disubstituted alkenes manifests the powerfulness and versatility of this strategy. Moreover, gram-scale synthesis with excellent yield and