34564-84-6Relevant academic research and scientific papers
Flow Chemistry Syntheses of Styrenes, Unsymmetrical Stilbenes and Branched Aldehydes
Bourne, Samuel L.,O'Brien, Matthew,Kasinathan, Sivarajan,Koos, Peter,Tolstoy, Paeivi,Hu, Dennis X.,Bates, Roderick W.,Martin, Benjamin,Schenkel, Berthold,Ley, Steven V.
, p. 159 - 172 (2013/03/13)
Two tandem flow chemistry processes have been developed. A single palladium-catalysed Heck reaction with ethylene gas provides an efficient synthesis for functionalised styrenes. Through further elaboration the catalyst becomes multi-functional and performs a second Heck reaction providing a single continuous process for the synthesis of unsymmetrical stilbenes. In addition, the continuous, rhodium-catalysed, hydroformylation of styrene derivatives with syngas affords branched aldehydes with good selectivity. Incorporation of an in-line aqueous wash and liquid-liquid separation allowed for the ethylene Heck reaction to be telescoped into the hydroformylation step such that a single flow synthesis of branched aldehydes directly from aryl iodides was achieved. The tube-in-tube semi-permeable membrane-based gas reactor and liquid-liquid separator both play an essential role in enabling these telescoped flow processes.
Pd-catalyzed oxidative cross-coupling of N-tosylhydrazones with arylboronic acids
Zhao, Xia,Jing, Jing,Lu, Kui,Zhang, Yan,Wang, Jianbo
supporting information; experimental part, p. 1724 - 1726 (2010/07/06)
The Pd-catalyzed reaction of N-tosylhydrazones and arylboronic acids provides olefin derivatives. This oxidative cross-coupling is suggested to proceed through a migratory insertion process of a Pd carbene intermediate.
Substituent effects in solvolysis of 1,1-diphenylethyl p-nitrobenzoates. Symmetrically disubstituted and monosubstituted systems
Fujio, Mizue,Uddin, Md. Khabir,Kim, Hyun-Joong,Tsuno, Yuho
, p. 544 - 549 (2007/10/03)
The rates of solvolysis of 1,1-diarylethyl p-nitrobenzoates and chlorides were determined conductimetrically at 25 °C in 80% (v/v) aqueous acetone. Applying the Yukawa-Tsuno (Y-T) equation, the symmetrical (X = Y) subseries gave a precise additivity relationship for the whole substituent range with a rsym value of -3.78 and an rsym value of 0.77. While any Y subsets gave statistically less reliable Y-T correlations, the apparent ρ value changed significantly depending on the fixed Y substituents; the ρ value decreases with the more electron-donating fixed substituents Y, which is compatible with the Hammond shift of the transition state coordinate. Nevertheless, the concave correlations of the More O'Ferrall non-linearity relationship for any Y subsets are not in line with what is expected from the reactivity-selectivity relationship suggesting an anti-Hammond shift of transition state. However, we found a precise extended Bronsted relationship between the pKR+ values of 1,1-diarylethylenes and solvolysis rate process with a constant slope of α = 1.03 ± 0.03. This is direct evidence indicating that there is no significant shift of the transition-state coordinate over the whole range of substituent change. Copyright
