1062-99-3

Upstream product

• 123-91-1 1,4-dioxane 
• 728-87-0 4,4'-Dimethoxybenzhydrol 
• 76-03-9 trichloroacetic acid 
• 64-19-7 acetic acid 
• 615-93-0 2,5-Dichloro-1,4-benzoquinone 
• 726-18-1 4,4'-dianisylmethane 
• 118-75-2 chloranil 
• 7525-23-7 4,4'-dimethoxydiphenylmethyl chloride 
• 1214-54-6 5-benzylidene Meldrum's acid 
• 100-52-7 benzaldehyde 
• 3709-27-1 5-benzyl-2,2-dimethyl-1,3-dioxane-4,6-dione 
• 855229-58-2 bis(4-methoxyphenyl)methyl nitrite 
• 174968-73-1 bis(4-methoxyphenyl)methyl trimethylsilyl ether 
• 640-19-7 fluoroacetamide 

Downstream Products

• 90-96-0 bis(p-methoxyphenyl)methanone 
• 726-18-1 4,4'-dianisylmethane 
• 78073-91-3 α-deutero-4,4'-dimethoxydiphenylmethane 
• 56652-42-7 α,α-dideutero-4,4'-dimethoxydiphenylmethane 

Relevant academic research and scientific papers

Competitive decay pathways of the radical ions formed by photoinduced electron transfer between quinones and 4,4′-dimethoxydiphenylmethane in acetonitrile

The reactivity of the cation radical of (4-MeOC6H4)2CH2 photosensitized by 1,4-benzoquinone (BQ), 2,5-dichloro-1,4-benzoquinone (Cl2BQ), and tetrachloro-1,4-benzoquinone (chloranil, CA) was investigated in acetonitrile. The main photoreaction products obtained by steady-state irradiation were identified to be: (4-MeOC6H4)2CHOC6H4OH, sensitized by BQ; (4MeOC6H4)2CHCl, sensitized by Cl2BQ; (4-MeOC6H4)2CHOH, sensitized by CA. The mechanism of their formation was investigated by nanosecond laser flash photolysis that allowed transient species (radical ions, neutral radicals, and ions) to be detected and characterized in terms of absorption spectra, formation quantum yields, and decay rate constants. For all systems, the interaction between the triplet quinone (Q) and (4-MeOC6H4)2CH2 produced the corresponding radical ions (quantum yield φ ≥ 0.72) which mainly decay by back electron transfer processes. Less efficient reaction routes for the radical ions Q.- and (4-MeOC6H4)2CH2.+ were also: i) the proton-transfer process with the formation of the radical (4MeOC6H4)2CH. by use of Cl2BQ; ii) the hydrogen-transfer process with the formation of the cation (4-MeOC6H4)2CH+ in the case of CA. Instead, BQ sensitized a much higher yield of BQH. and (4MeOC6H4)2CH., mainly by the direct interaction of triplet BQ with (4MeOC6H4)2CH2. It was also shown that the presence of salts decreases significantly the rate of the back electron transfer process and enhances the quantum yields of formation of the neutral radicals and ions when Cl2BQ and CA are used, respectively. The behavior of BQ.-, Cl2BQ.-, and CA.- appears to be mainly determined by the Mulliken charges on the oxygen atom obtained from quantum mechanical calculations with the model B3LYP/6-311G(d,p). Spin densities seem to be much less important.

One-Step Hydroxy Substitution of 4,4′-Dimethoxybenzhydrol with Amides, Lactams, Carbamates, Ureas and Anilines

A series of amides, lactams, carbamates, ureas and anilines, equipped with various functionalities, were readily N-alkylated with the 4,4′-dimethoxybenzhydryl residue by reaction with 4,4′-dimethoxybenzhydrol [bis(4-methoxyphenyl)methanol] in acetic acid,

Iodine-catalyzed transformation of aryl-substituted alcohols under solvent-free and highly concentrated reaction conditions

Iodine-catalyzed transformations of alcohols under solvent-free reaction conditions (SFRC) and under highly concentrated reaction conditions (HCRC) in the presence of various solvents were studied in order to gain insight into the behavior of the reaction intermediates under these conditions. Dimerization, dehydration and substitution were the three types of transformations observed with benzylic alcohols. Dimerization and substitution reactions were predominant in the case of primary- and secondary alcohols, whereas dehydration prevailed in the case of tertiary alcohols. The relative reactivity of substituted 1-phenylethanols in I2-catalyzed dimerization under SFRC provided a good Hammett plot ρ+ = -2.8 (r2 = 0.98), suggesting the presence of electron-deficient intermediates with a certain degree of developed charge in the rate-determining step.

Di- and triarylmethylium ions as probes for the ambident reactivities of carbanions derived from 5-benzylated Meldrum's acid

The kinetics of the reactions of carbocations with carbanions 1 derived from 5-benzyl-substituted Meldrum's acids 1-H (Meldrum's acid=2,2-dimethyl-1,3- dioxane-4,6-dione) were investigated by UV/Vis spectroscopic methods. Benzhydryl cations Ar2CH+ added exclusively to C-5 of the Meldrum's acid moiety. As the second-order rate constants (kC) of these reactions in DMSO followed the linear free-energy relationship lg k=s N(N+E), the nucleophile-specific reactivity parameters N and s N for the carbanions 1 could be determined. In contrast, trityl cations Ar3C+ reacted differently. While tritylium ions of low electrophilicity (E-2) reacted with 1 through rate-determining β-hydride abstraction, more Lewis acidic tritylium ions initially reacted at the carbonyl oxygen of 1 to form trityl enolates, which subsequently reionized and eventually yielded triarylmethanes and 5-benzylidene Meldrum's acids by hydride transfer.

Iodine-catalyzed disproportionation of aryl-substituted ethers under solvent-free reaction conditions

Iodine was demonstrated to be an efficient catalyst for disproportionation of aryl-substituted ethers under solvent-free reaction conditions. Variously substituted 1,1,1′,1′-tetraaryldimethyl ethers were transformed into the corresponding diarylketone and diarylmethane derivatives. I 2-catalyzed transformation of 4-methoxyphenyl substituted ethers yielded mono- and dialkylated Friedel-Crafts products as well. Treatment of trityl alkyl and trityl benzyl ethers with a catalytic amount of iodine produced triphenylmethane and the corresponding aldehydes and ketones. The electron-donating substituents facilitated the reaction, while the electron-withdrawing groups retarded it; the difference in reactivity is not very high. Such an observation may be in favour of hydride transfer, predominantly from the less electron rich side of the ether with more stable carbocation formation. With the isotopic studies it was established that a substantial portion of the C-H bond scission took place in the rate-determining step, while the carbonyl oxygen atom originated from the starting ether, and not from the air. The transformation took place under air and under argon, and HI was not a functioning catalyst.

Etherification of darylmethanols and 1-phenylalkan-1-ols over platinum on carbon

In the presence of platinum on carbon (Pt/C), diarylmethanols and donor substituted 1-phenylalkan-1-ols undergo cross-etherification with primary and secondary alcohols.

Anomalous reactivity of radical cations produced by photosensitized oxidation of 4-methoxybenzyl alcohol derivatives: Role of the sensitizer

Steady-state and nanosecond laser flash photolysis measurements of 4-methoxybenzyl alcohol (1a), 4-methoxy-α-methylbenzyl alcohol (1b), 4,4′-dimethoxydiphenylmethanol (1c) and 4-methoxy-α,α′- dimethylbenzyl alcohol (1d) were carried out in air-equilibrated CH 2Cl2 and CH3CN solutions, in the presence of 9,10-dicyanoanthracene (DCA) and N-methylquinolinium tetrafluoroborate (NMQ +BF4-) as sensitizers. In particular, steady-state irradiation with DCA produced carbonyl compounds and, with NMQ +BF4-, carbonyl compounds, ethers (substrates 1a-c) and styrene (substrate 1d) while time-resolved investigations gave evidence of charged species produced upon irradiation. The effect of solvent polarity on the reactivity was investigated; in the case of DCA, the reactivity increased with the solvent polarity, while the opposite was obtained when NMQ+BF4- was used. Quantum mechanical calculations at semiempirical (INDO/1-CI) and DFT (B3LYP/6-311G(d)) levels were used to support transient assignments and to obtain the charge and spin density distributions, respectively. The different photooxidation mechanisms operative with the neutral and charged sensitizer were rationalized in terms of the reactivity of free and complexed radical cations, respectively. the Owner Societies.

Ambident reactivity of the nitrite ion revisited

(Chemical Equation Presented) Lost control: The rationalization of the ambident reactivity of NO2- by the change between charge control to orbital control has to be revised. SN1-type reactions of carbocations with NO2- give kinetically controlled product mixtures only when these reactions proceed without activation energy (diffusion control). Activation-controlled SN1 alkylations are reversible and lead to the thermodynamically more stable nitro compounds.

The role of aromatic radical cations and benzylic cations in the 2,4,6-triphenylpyrylium tetrafluoroborate photosensitized oxidation of ring-methoxylated benzyl alcohols in CH2Cl2 solution

A steady-state and laser flash photolysis (LFP) study of the TPPBF 4-photosensitized oxidation of ring-methoxylated benzyl alcohols has been carried out. Direct evidence on the involvement of intermediate benzyl alcohol radical cations and benzylic cations in these reactions has been provided through LFP experiments. The reactions lead to the formation of products (benzaldehydes, dibenzyl ethers, and diphenylmethanes) whose amounts and distributions are influenced by the number and relative position of the methoxy substituents. This behavior has been rationalized in terms of the interplay between the stabilities of benzyl alcohol radical cations and benzyl cations involved in these processes. A general mechanism for the TPPBF 4-photosensitized reactions of ring-methoxylated benzyl alcohols has been proposed, where the a-OH group of the parent substrate acts as the deprotonating base promoting α-C-H deprotonation of the benzyl alcohol radical cation (formed after electron transfer from the benzyl alcohol to TPP*) to give a benzyl radical and a protonated benzyl alcohol, precursor of the benzylic cation. This hypothesis is in contrast with previous studies, where formation of the benzyl cation was suggested to occur from the neutral benzyl alcohol through the Lewis acid action of excited TPP+ (TPP*).

A study of hydrogenation of benzhydrols in the presence of catalytic amount of triflic acid

The ionic hydrogenation of diarylcarbinols by triethylsilane, in the presence of catalytic amount of triflic acid proceeds via dibenzhydryl ethers. These ethers do not disproportionate to benzophenones and diphenylmethanes but are reduced by triethylsilane to diarylmethanes.