42289-57-6

Upstream product

• 116664-91-6 4-(Phenyl-p-tolyl-methoxy)-benzonitrile 
• 620-83-7 1-methyl-4-(phenylmethyl)benzene 
• 134-84-9 4-Methylbenzophenone 
• 1580541-52-1 4-methylbenzhydryl trichloroacetate 
• 1580541-47-4 4-methylbenzhydryl dichloroacetate 
• 622-22-0 1,2-dibenzyloxyethane 
• 1517-63-1 4-methylphenyl(phenyl)methanol 
• 779-14-6 p-methyl-a-phenylbenzylchloride 

Downstream Products

• 620-83-7 1-methyl-4-(phenylmethyl)benzene 
• 139732-72-2 phenylsilyl cation 
• 220322-74-7 1-methyl-4-(1-phenylbut-3-en-1-yl)benzene 
• 1517-63-1 4-methylphenyl(phenyl)methanol 

Relevant academic research and scientific papers

Solvolytic Behavior of Aryl and Alkyl Carbonates. Impact of the Intrinsic Barrier on Relative Reactivities of Leaving Groups

The effect of negative hyperconjugation on the solvolytic behavior of carbonate diesters has been investigated kinetically by applying the LFER equation log k = sf(Ef + Nf). The observation that carbonate diesters solvolyze faster than the corresponding carboxylates and that the enhancement of aromatic carbonates is more pronounced indicates that the negative hyperconjugation and π-resonance within the carboxylate moiety is operative in TS. The plots of ΔG? vs approximated ΔrG° for solvolysis of benzhydryl aryl/alkyl carbonates and benzhydryl carboxylates reveal that a given carbonate solvolyzes over the higher Marcus intrinsic barrier and over the earlier transition state than carboxylate that produces an anion of similar stability. Due to the lag in development of the electronic effects along the reaction coordinate, the impact of the intrinsic barrier on solvolytic behavior of carbonates is more important than in the case of carboxylates and phenolates. Consequently, the solvolytic reaction constants (sf) are generally lower for carbonates than for carboxylates. Because of considerable lower reaction constants of carbonates, an inversion of relative reactivities between aryl/alkyl carbonate and another leaving group of similar nucleofugality (Nf) may occur if the electrofuge moiety of a substrate is switched.

Solvolytic Behavior of Aliphatic Carboxylates

The leaving group abilities (nucleofugalities) of a series of aliphatic carboxylates have been obtained by determining the nucleofuge-specific parameters (Nf and sf) from solvolysis rate constants of X,Y-substituted benzhydryl carboxylates in a series of aqueous ethanol mixtures by applyication of the linear free energy relationship (LFER) equation: log k = sf (Ef + Nf). These values can be employed to compare reactivities of carboxylates with those of other leaving groups previously included in the nucleofugality scale, and also to estimate the solvolysis rates of various carboxylates. It is confirmed that the inductive effect is the most important variable governing the reactivities of halogenated carboxylates in solution. Moreover, both the Hammett correlation and the solvolytic activation parameters have revealed a strong influence of the inductive effect on the nucleofugality of alkyl-substituted carboxylates. The reaction constants (sf) indicate that carboxylate substrates with weaker leaving groups solvolyze via later, more carbocation-like, transition states, which is in accord with the Hammond postulate. In addition, due to the weaker demand for solvation of transition states that produce more strongly stabilized benzhydrylium ions, in which more efficient charge delocalization occurs, the reaction constants (sf) obtained with most of the leaving groups investigated here increase as the polarity of the solvent decreases.

Generation of diarylcarbenium ion poolsviaelectrochemical C-H bond dissociation

The "cation pools" of diarylcarbenium ions have been generated by the low-temperature electrochemical oxidation of diphenylmethane derivatives. In addition to diphenylmethanes having various substituents, 9,10-dihydroanthracene, dibenzosuberane, and xanth

Intramolecular benzyl-benzyl interactions in protonated benzyl diethers in the gas phase. Effects of internal hydrogen bonding

Protonated molecules of a variety of benzyl diethers, produced by chemical ionization (CI), undergo a unique rearrangement yielding relatively abundant mlz 181 C14H13+ ions, both in the ion source and under collision-induc

Flash-Photolysis Generation and Reactivities of Triarylmethyl and Diarylmethyl Cations in Aqueous Solutions

A series of 18 triarylmethyl cations and 10 diarylmethyl cations have been generated by nanosecond laser flash photolysis of cyanide, 4-cyanophenyl ether, and acetate precursors in acetonitrile/water (AN/W) solutions and first-order rate constants for their reaction with the solvent (ks) have been directly measured following the decay in their optical density.In the standard solvent employed, 1:2 AN/W, the triarylmethyl cations which were studied had ks values at 20 deg C ranging from 1E1 s-1 (for the 4,4',4''-(MeO)3-substituted ion) to 9*1E6 s-1 (4,4'-(CF3)2), while diarylmethyl cations had ks values ranging from 1E5 s-1 (4,4'-(MeO)2) to 3*1E7 s-1 (4,4'-Me2).The parent diphenylmethyl cation and its derivative with one 4-methyl substituent were too short-lived (s of varying the amounts of acetonitrile were investigated for several cations.As water is added to 100percent acetonitrile, ks increases significantly, but at around 15percent by volume water, there is a leveling and from that point to 100percent water, ks is almost unchanged, decreasing by about 20percent.A plot of log ks versus ?+ constructed for the triarylmethyl cations shows significant deviations from linearity for the points for the ? donors, in the direction which indicates that ?+ is underestimating the stabilizing effect of these substituents for a fully formed cation.A plot versus ?C+, a parameter obtained from the analysis of NMR spectra of solutions of carbocations, is reasonably linear.A two-parameter correlation indicates that polar andresonance interactions of substituents do not proceed in parallel along the reaction coordinate, the addition of water to cation resulting at the transition state in the loss of 73percent of the equilibrium resonance effect but only a 33percent loss of the polar effect.A rate-equilibrium plot (log ks versus pKR) was constructed which covers 23 pKR units.A single line of slope 0.64 can be drawn to include the entire set of data for both triarylmethyl and diarylmethyl cations.From a small extrapolation the ks value for the tert-butyl cation in water is obtained as 1E10.5 s-1.

The Torsional Barrier around the Phenyl-C+ Bond in Phenylcarbenium Ions

The barrier to rotation around the phenyl-carbenium carbon bond in a series of carbenium ions R1R2C+Ph (with R1 and/or R2=H, CH3, cyclopropyl, and C6H4X) has been measured by complete line-shape analysis of the n.m.r. spectra or by the spin saturation transfer method. ΔG(excit.) Values range from 36 to 78 kJ mol-1.The results are discussed in terms of steric and electronic contributions and the relationship of the 13C chemical shift of the carbenium centre with the ?C+ values of the para-substituent is analysed.