6380-16-1Relevant articles and documents
A methylation platform of unconventional inert aryl electrophiles: Trimethylboroxine as a universal methylating reagent
Feng, Boya,Yang, Yudong,You, Jingsong
, p. 6031 - 6035 (2020/07/10)
Methylation is one of the most fundamental conversions in medicinal and material chemistry. Extension of substrate types from aromatic halides to other unconventional aromatic electrophiles is a highly important yet challenging task in catalytic methylation. Disclosed herein is a series of transition metal-catalyzed methylations of unconventional inert aryl electrophiles using trimethylboroxine (TMB) as the methylating reagent. This transformation features a broad substrate type, including nitroarenes, benzoic amides, benzoic esters, aryl cyanides, phenol ethers, aryl pivalates and aryl fluorides. Another important merit of this work is that these widespread "inert"functionalities are capable of serving as directing or activating groups for selective functionalization of aromatic rings before methylation, which greatly expands the connotation of methylation chemistry.
Unsymmetrical 4,6-diamino-2-methyl-5-nitropyrimidine synthesis via 4,6-bis(tosylates)
Cain, Gary A.,Beck, James P.
, p. 439 - 446 (2007/10/03)
Chlorides have traditionally been used as leaving groups for the introduction of 4- and 6-heteroatomic substituents onto pyrimidines. Use of 4,6-dichloro-2-methyl-5-nitropyrimidine allows the sequential introduction of different 4- and 6-heteroatomic substituents onto this core; however, this reagent is highly hazardous to handle. We have found that the analogous 4,6-bis(tosylate) offers a less hazardous substance which undergoes the same nucleophilic aromatic substitution chemistry as the dichloride, including sequential introduction of different nucleophiles.
