Methanol, diphenyl

Figure 4.2 Microsoft Excel spreadsheet output of green metrics analysis for the synthesis of diphenyl-methanol using the Crignard methodology.

Lewis, T. W. Curtin, D. Y. Paul, I. C. Thermal, photochemical and photonucleated thermal dehydration of /j-hydroxytriary I methanols in the solid state. (3,5-Dimethyl-4-hydroxyphenyl)diphenyl methanol and (3,5-dibromo-4-hyrdoxyphenyl)di phenyl methanol X-ray crystallography of (4-hydroxyphenyl)diphenyl methanol and its 3,5-dimethyl derivative. J. Am. Chem. Soc. 1979, 101, 5717-5725. 

Mejorado investigated the asymmetric addition of various organometallic nucleophiles using method A, but the reaction could not be catalyzed. The intermediates proved to be far too reactive. However, he established that the addition of a stoichiometric amount of a preformed chiral complex [an admixture of Taddol (r/om-a, -(dimethyl-1,3-dioxolane-4,5-diyl)bis(diphenyl methanol)) and EtMgBr] to 5 affords some enantiomeric excess in the resulting phenol product 6 (Fig. 4.12).13... 

Phenolic compounds were confirmed to be very stable against thermal treatment. Diphenyl methanol and benzophenone were stable against decomposition but hydrogenated to form diphenyl -methane quantitatively. Phenyl benzyl ketone was found to be partially hydrogenated or decarbonylated to form diphenyl alkanes. 

Auch bei der Umsetzung von 4-Methyl-benzolsulfonsaure-imidazolid und Kalium-imidazolid mit Diphenyl-methanol wird C-Alkylierung beobachtet. Hier entsteht ein Gemisch aus 1-(22%), 2- (12%) und 4(5)-Diphenylmethyl-imidazol (24%)845. Beim Belichten von Imidazol und Diazo-diphenyl-methan in Tetrahydrofuran entsteht das gleiche Produktgemisch845. 

There are numerous reactions of interest that fit the description mentioned above. For example, the reaction of tert-butoxyl with aliphatic alcohols is essentially invisible or silent in nLFP. A practical example would be the reaciton of f-BuO" with 2-propanol, in which the reaction with benzhydrol (diphenyl methanol) could be used as a probe. The mechanism is shown in Scheme 18.3 for this example. 

In the examples of Figures 18.8 and 18.9 the probe molecule is diphenyl-methanol, and it reacts with ferf-butoxyl radicals as shown in Scheme 18.3. Usual probe concentrations were between 50 and 200 mM. Figure 18.8 shows a representative trace for the formation of the ketyl radical from diphenylmethanol (i.e., the same formed by photoreduction of benzophenone), the only detectable species in the system. Figure 18.8 shows how the value of growth, given by the slope of the plots, changes with substrate (1,7-octadiene) concentration, as predicted by Eq. 18. 

Diphenyl-methanol, Diphenylmethylol, Benz-hydrol or Diphenylcarhinol, (CgHs CHOH, mw 184,23 ndls, mp 68—69°, bp 298.5° si sol in w v sol in ale, eth, chlf CC14 insol in iigroin can be prepd by reduction of benzophenone (C8H5)2CO with Mg or Zn dust and by other methods (Refs 1 2)... 

Much work in the review period has concerned enantioselective substitution in five-membered heterocyclics. The enantioselective alkylation of some pyrroles by unsaturated 2-acylimidazoles catalysed by the bis(oxazolinyl)pyridine-scandium(in) triflate complex (31) has been reported.39 Compound (33) is formed in 98% yield and 94% ee from the 2-acylimidazole (32) and pyrrole at —40 °C. A series of enantiomer- ically pure aziridin-2-ylmethanols has been tested as catalysts in the alkylation of /V-mclhylpyrrolc and (V-methylindole by ,/l-unsalura(cd aldehydes.40 Enantiomeric excesses of up to 75% were observed for the alkylation of /V-mcthylpyrrole by ( >crotonaldehyde using (2.S ,3.S )-3-mclhylazirin-2-yl(diphenyl)methanol TFA salt as catalyst to form (34). 

A completely different course of reaction was established when one or both benzylic protons in the benzyl alcohol molecule were replaced with phenyl or methyl substituents diphenyl methanol gives bis(diphenylmethyl) ether, while 2-phenyl-2-propanol was transformed to 2,4-diphenyl-4-methyl-l-pentene)106 (Scheme 40). 

Benzyl alcohol and benzene in a mixture of glacial acetic acid and sulfuric acid give diphenylmethane even at room temperature,646 and diphenyl-methanol gives an almost theoretical yield of diphenyl-p-tolylmethane when boiled with toluene and phosphoric oxide 647 diphenylacetic acid is formed in yields up to 96% on reaction of mandelic acid with benzene in the presence of aluminum chloride.648... 

The hypothesis has been verified by the reaction of (1-naphthyl)diphenyl-methanol using P(l-Nap)3 as ligand, in which naphthalene and benzophenone are produced quantitatively (Eq. 29) [52]. In this case, the addition of catalytic amounts of bromobenzene and CS2CO3 promotes the reaction. Thus, one of the most bulky aromatic phosphines, P( 1 -Nap)3, appears to be a suitable ligand for the dehydroarylation of triarylmethanols,but to be too bulky for their aryl-aryl... 

The -carbon elimination becomes the main path when PCy3 is used. Reaction of triphenylmethanol (18) with bromobenzene gave rise to biphenyl (19) in 93 % yield, along with o-terphenyl (10) in 6 % yield. For the arylation, aryl chlorides can be used as coupling partners. The coupling of 2,6-dimethylphenyl(diphenyl)-methanol (20) with chlorobenzene afforded, 2,6-dimethylbiphenyl (21) in 98%... 

A review has illustrated the importance of atomic-level DFT studies in elucidation of the function of hydrogen bonds in organocatalytic reactions through influence on the mechanism of substrate activation and orientation, and the stabilization of transition states and intermediates. Examples discussed include stereoselective catalysis by bifunctional thioureas, solvent catalysis by fluorinated alcohols in epoxidation by hydrogen peroxide, and intra-molecular cooperative hydrogen bonding in trans-a,a -(dimethyl-l,3-dioxolane-4,5-diyl)bis(diphenyl methanol) (TADDOL) (7)-type catalysts. ... 

Copper(I) complexes of trans-a, o -(dimethyl-l,3-dioxolane-4,5-diyl)bis(diphenyl methanol) (TADDOL)-based ligands, such as (255), with bulky substituents at the... 

The sterically more demanding benzophenone is reduced to yield diphenyl methanol after hydrolysis. 

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