منابع مشابه
A tetra-substituted chrysene: orientation of multiple electrophilic substitution and use of a tetra-substituted chrysene as a blue emitter for OLEDs.
The first tetra-substituted non-fused chrysene, 3,6,9,12-tetrakis(4-tert-butylphenyl)chrysene with blue electroluminescence at 450 nm, and with a radiance of 500 cd m(-2), was synthesized by a two-step procedure: direct bromination of chrysene in trimethyl phosphate, followed by palladium-catalyzed cross-coupling of tetrabromochrysene and tert-butylphenylboronic acid .
متن کاملA General Method for the Synthesis of Enantiomerically Pure â-Substituted, â-Amino Acids through r-Substituted Succinic Acid Derivatives
A general procedure for the synthesis of enantiopure â-substituted, â-amino acids is presented. Alkylation of the sodium enolates derived from chiral N-acyloxazolidinone imides 2 (R ) Me, i-Pr, t-Bu, Ph, Bn) with tert-butyl bromoacetate afforded the 2-substituted succinate derivatives 3 in good yields (82-89%) and with high selectivity (g93:7). Following hydrolysis, Curtius rearrangement of the...
متن کاملMicrobial desulfonation of substituted naphthalenesulfonic acids and benzenesulfonic acids.
Sulfur-limited batch enrichment cultures containing one of nine multisubstituted naphthalenesulfonates and an inoculum from sewage yielded several taxa of bacteria which could quantitatively utilize 19 sulfonated aromatic compounds as the sole sulfur source for growth. Growth yields were about 4 kg of protein per mol of sulfur. Specific degradation rates were about 4 to 14 mu kat/kg of protein....
متن کاملOccurrence and Distribution of Chrysene and its Derivatives in Crude Oils and Source Rock Extracts from Niger Delta, Nigeria
Crude oils and source rocks from the northern and offshore Niger Delta basin, Nigeria, have been characterized by gas chromatography-mass spectrometry in terms of their origin and thermal maturity based on the distribution of chrysene and its derivatives. The crude oils and source rocks were characterized by the dominance of chrysene over benzo[a]anthracene. 3-methylchrysene predominated over o...
متن کاملSynthesis and Resolution of Substituted Pipecolic Acids
-A new general method for the preparation of 2-alkyl-pipecolic acids has been developed. The syntheses of 2-methyl-, 2-benzyland cis-6-methylpipecolic acids are described. ( ) S and (+)R-2-methylpipecolic acids were resolved by fractional crystallization of the quinine salt of their N-carbobenzoxy derivative. Isolation of (-)S-cis-6-methylpipecolic acid required the use of 4-phenylbenzyloxycarb...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature
سال: 1933
ISSN: 0028-0836,1476-4687
DOI: 10.1038/131402b0