14804-27-4Relevant 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.
Efficient synthesis of (R)-ochratoxin alpha, the key precursor to the mycotoxin ochratoxin A
Lenz, Cesar Antonio,Rychlik, Michael
supporting information, p. 883 - 886 (2013/02/25)
Two new routes for the synthesis of enantiomerically pure ochratoxin alpha ((3R)-OTα) are presented, which is the key intermediate for the synthesis of ochratoxin A (OTA) by coupling reaction with the amino acid l-phenylalanine. The key step of both routes is the one pot directed ortho-metalation/alkylation/ lactonization of unprotected and suitably functionalized aromatic carboxylic acids, using lithium tetramethylpiperidide (LTMP) and (R)-propylene oxide.
Kaolin-assisted Aromatic Chlorination and Bromination
Hirano, Masao,Monobe, Hiroyuki,Yakabe, Shigetaka,Morimoto, Takashi
, p. 662 - 663 (2007/10/03)
Moist kaolin catalyses the regioselective and high-yielding chlorination and bromination of C6H5OR (R = C1-C8 alkyl. Bu1, allyl, cyclohexyl, benzyl) to 4-XC6H4OR (X = Cl and Br, respectively) with NaCl02 and Mn(acac)3 in CH2Cl2 in the absence and presence of NaBr, respectively, under mild and neutral conditions.
Selective aromatic chlorination of activated arenes with sodium chlorite, (salen)manganese(III) complex, and alumina in dichloromethane
Hirano,Yakabe,Monobe,Morimoto
, p. 1905 - 1912 (2007/10/03)
The reaction of alkyl phenyl ethers with sodium chlorite in dichloromethane in the presence of a (salen)manganese(III) complex and alumina preloaded with a small amount of water afforded monochlorination products with unusually high para selectivities under mild conditions. The NaClO2-based biphasic system can also be successfully used for the regioselective monochlorination of substituted anisoles and polymethoxybenzenes.
