2381-21-7Relevant articles and documents
Fluorescence enhancement of pyrene chromophores induced by alkyl groups through σ-π Conjugation: Systematic synthesis of primary, secondary, and tertiary alkylated pyrenes at the 1, 3, 6, and 8 positions and their photophysical properties
Niko, Yosuke,Kawauchi, Susumu,Otsu, Shun,Tokumaru, Katsumi,Konishi, Gen-Ichi
, p. 3196 - 3207 (2013)
We have systematically synthesized 1-, 3-, 6-, and 8-alkyl-substituted pyrene derivatives using the latest synthesis methods and investigated the effects of alkyl substitution on the photophysical properties of the pyrene chromophore. Like the trimethylsi
Alternative Routes for Reductive Alkylations in Liquid Ammonia and Their Selection via Spectroscopic Evidence
Muellen, Klaus,Huber, Walter,Neumann, Gerd,Schnieders, Christoph,Unterberg, Heinz
, p. 801 - 807 (1985)
A wide range of unsaturated hydrocarbons have been reduced with alkali metals in liquid ammonia and the carbanionic intermediates detected in situ by NMR and ESR spectroscopy.The substrates cluster into three different groups depending on whether they (i) persist as dianions, (ii) are protonated by ammonia to afford monohydro anions, or (iii) undergo further electron transfer/protonation steps to yield polyhydro derivatives.The alternative modes of behavior can be correctly predicted on the basis of the relevant atom localization energies.The spectroscopic findings are extremely helpful in rationalizing the results of reductive alkylation experiments and in controlling the regioselectivity of novel quenching reactions.
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.
