124268-14-0Relevant academic research and scientific papers
Pd-Catalyzed ipso, meta-Dimethylation of ortho-Substituted Iodoarenes via a Base-Controlled C-H Activation Cascade with Dimethyl Carbonate as the Methyl Source
Wu, Zhuo,Wei, Feng,Wan, Bin,Zhang, Yanghui
, p. 4524 - 4530 (2021/05/04)
A methyl group can have a profound impact on the pharmacological properties of organic molecules. Hence, developing methylation methods and methylating reagents is essential in medicinal chemistry. We report a palladium-catalyzed dimethylation reaction of ortho-substituted iodoarenes using dimethyl carbonate as a methyl source. In the presence of K2CO3 as a base, iodoarenes are dimethylated at the ipso- and meta-positions of the iodo group, which represents a novel strategy for meta-C-H methylation. With KOAc as the base, subsequent oxidative C(sp3)-H/C(sp3)-H coupling occurs; in this case, the overall transformation achieves triple C-H activation to form three new C-C bonds. These reactions allow expedient access to 2,6-dimethylated phenols, 2,3-dihydrobenzofurans, and indanes, which are ubiquitous structural motifs and essential synthetic intermediates of biologically and pharmacologically active compounds.
A New Rearrangement of Alkoxybenzyl Anions
Bates, Robert B.,Siahaan, Teruna J.,Suvannachut, Kessara
, p. 1328 - 1334 (2007/10/02)
Alkyl groups migrate from oxygen to carbon in alkyl aryl ethers which have been metalated in benzylic positions. 2,6-Dimethylanisole provides a variety of 2,6-dialkylphenols and their ethers in 45-80percent yields.Rearrangement products are obtained in 10-30percent yields from other dimethylanisoles and from methylanisoles.The reactions appear to proceed, like Wittig rearrangements, by homolytic cleavage of the alkyl-oxygen bond followed by recombination of the resulting radical pair in a different way.The rearrangements can be avoided by using methyl ethers and working at or below room temperature.
