1122-81-2Relevant articles and documents
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Notari,Pines
, p. 2945 (1960)
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Photocatalytic Hydromethylation and Hydroalkylation of Olefins Enabled by Titanium Dioxide Mediated Decarboxylation
Zhu, Qilei,Nocera, Daniel G.
supporting information, p. 17913 - 17918 (2020/12/04)
A versatile method for the hydromethylation and hydroalkylation of alkenes at room temperature is achieved by using the photooxidative redox capacity of the valence band of anatase titanium dioxide (TiO2). Mechanistic studies support a radical-based mechanism involving the photoexcitation of TiO2 with 390 nm light in the presence of acetic acid and other carboxylic acids to generate methyl and alkyl radicals, respectively, without the need for stoichiometric base. This protocol is accepting of a broad scope of alkene and carboxylic acids, including challenging ones that produce highly reactive primary alkyl radicals and those containing functional groups that are susceptible to nucleophilic substitution such as alkyl halides. This methodology highlights the utility of using heterogeneous semiconductor photocatalysts such as TiO2 for promoting challenging organic syntheses that rely on highly reactive intermediates.
A Convenient Method for the Regioselective Synthesis of 4-Alkyl(aryl)pyridines Using Pyridinium Salts
Akiba, Kin-ya,Iseki, Yuji,Wada, Makoto
, p. 1994 - 1999 (2007/10/02)
RCu.BF3 reacted with 1-ethocycarbonylpyridinium chloride at the 4-position with almost complete regioselectivity (>99percent) to afford the corresponding 1,4-dihydropyridine derivatives in high yields (81-94percent).The dihydropyridines were oxidized by oxygen to give 4-alkyl(aryl)pyridines (38-68percent).Grignard reagents also reacted with 1-t-butyldimethylsilylpyridinium triflate with almost complete regioselectivity (>99percent) to afford the corresponding 1,4-dihydropyridines, which were easily oxidized to give 4-substituted pyridines in higher yields than above (58-70percent).
