The reactions of dioxanyl and cyclohexylradicals with 2- and 3-X-pyridines (X = CN, COMe, CO2Me) give a single substitution product deriving by addition at the 5- and 6-positions respectively; with 4-X-pyridines substitution occurs preferentially at the 3-position. If the reactions are carried out with protonated pyridines other positional isomers are obtained. From the synthetic point of view the
Transition-metal-free cross-dehydrogenative alkylation of pyridines under neutral conditions
作者:Xin Li、Hao-Yuan Wang、Zhang-Jie Shi
DOI:10.1039/c3nj00095h
日期:——
A mild and efficient method has been developed for the direct dehydrogenative alkylation of unprotonated pyridine derivatives. The avoidance of using acids and transition-metals makes this protocol “greener” and more practical for the synthesis of substituted pyridines.
Visible-Light-Induced PhI(OAc)2-Mediated Alkylation of Heteroarenes with Simple Alkanes and Ethers
作者:Lusina Mantry、Parthasarathy Gandeepan
DOI:10.1021/acs.joc.4c00140
日期:2024.5.3
The direct alkylation of heteroarenes with alkanes has been successfully achieved through visible-light-induced hypervalent iodine-mediated C–H functionalization of both coupling partners at ambient temperatures. This reaction proceeds via the in situ generation of nucleophilic alkyl radicals from alkanes through hydrogen atom transfer (HAT), followed by a Minisci-type reaction with heteroarenes. These