464-72-2

Usage

Uses

Used in Research and Development:
Benzopinacole is used as a research chemical for its unique properties and potential applications in the scientific community. It aids in the development and understanding of new chemical compounds and processes.
Used in Flame Resistant Materials:
In the Chemical Industry, Benzopinacole is used as a component in the production of flame-resistant resins. Its properties contribute to the enhancement of safety standards in materials that require fire-resistant qualities, such as in the construction and electronics industries.
Used in Pharmaceutical Applications:
Although not explicitly mentioned in the provided materials, Benzopinacole's unique chemical structure may also hold potential in the pharmaceutical industry for the development of new drugs or drug delivery systems, similar to the applications of Gallotannin in anticancer treatments and drug delivery systems. Further research would be required to explore these possibilities.

Purification Methods

Crystallise benzopinacol from EtOH. [Beilstein 6 IV 7053.]

InChI:InChI=1/C26H22O2/c27-25(21-13-5-1-6-14-21,22-15-7-2-8-16-22)26(28,23-17-9-3-10-18-23)24-19-11-4-12-20-24/h1-20,27-28H

Synthetic route

benzophenone (119-61-9) → tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With hydrogen sulfide; phosphorous acid trimethyl ester In diethylene glycol dimethyl ether for 2.75h; Product distribution; Irradiation; variation of solvents, reagents and conditions;	100%
With hydrogen sulfide; phosphorous acid trimethyl ester In diethylene glycol dimethyl ether for 2.75h; Irradiation;	100%
With iodine; magnesium In diethyl ether; benzene for 0.5h; pinacol coupling; sonication;	99%

2C13H10O(1-)*2Na(1+)*4C6H18N3OP → tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With hydrogenchloride	100%

(naphthalene)Yb(THF)3 → ytterbium hydroxide + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With benzophenone; hydrogen cation In tetrahydrofuran addn. of benzophenone in THF to the Yb-compd., hydrolysis; pptn. of Yb(OH)3, benzpinacol detd. in the THF soln. by LSC;	A 100% B 67%

benzophenone (119-61-9) → 1,1-Diphenylmethanol (91-01-0) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With LiCrH4*2LiCl*2THF In tetrahydrofuran at 25℃; for 12h;	A 98% B 2%
With triethylamine; cadmium(II) sulphide In methanol for 6h; Irradiation;	A 88% B 11%
With sodium tetrahydroborate; nickel dichloride In tetrahydrofuran at 20℃; for 0.25h;	A 88% B 4%

2C13H10O(1-)*3C6H18N3OP*Ca(2+) → tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With hydrogenchloride	98%
With hydrogenchloride	98%

benzophenone (119-61-9) + N-butylamine (109-73-9) → tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
In benzene for 20h; Product distribution; Quantum yield; Irradiation;	96%

α-acetoxy-α-phenylbenzeneacetic acid (3808-00-2) → tetraphenylethane-1,2-diol (464-72-2) + acetic anhydride (108-24-7)

Conditions	Yield
With triethylamine In acetonitrile Ambient temperature; electrolysis;	A 93% B n/a
With triethylamine In acetonitrile Product distribution; Ambient temperature; electrolysis;	A 93% B n/a

benzophenone (119-61-9) + ethyl acetoacetate (141-97-9) → tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
In benzene for 48h; Irradiation;	92%

4-Chloropyridine (626-61-9) + benzophenone (119-61-9) → 2-(4-pyridyl)propan-2-ol (15031-78-4) + diphenyl(pyridin-4-yl)methanol (1620-30-0) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
In water; isopropyl alcohol for 24h; Product distribution; Mechanism; Irradiation; conc. H2SO4 added;	A 19% B 6% C 90%

benzophenone (119-61-9) + SEC-BUTYLAMINE (33966-50-6) + n-pentanethiol (110-66-7) + tert-butylamine (75-64-9) → N-2-butylidene-2-aminobutane (38836-40-7) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
In benzene for 20h; Product distribution; Quantum yield; Irradiation;	A 76% B 90%

benzophenone (119-61-9) + benzophenone semicarbazone (14066-73-0) → 9H-fluoren-1-ol (6344-61-2) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
Irradiation;	A 89% B n/a

benzophenone (119-61-9) → 9H-fluoren-1-ol (6344-61-2) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With benzophenone semicarbazone Mechanism; Irradiation; other nitrogen-containing reagents;	A 89% B n/a
With propan-2-one azine In methanol Irradiation;	A 23% B 1.6 g

benzaldehyde (100-52-7) → tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With triethylamine; poly(p-phenylene) In methanol for 6h; Irradiation;	87%

benzophenone (119-61-9) + (trimethylsilyl)potassium (56859-17-7) → 1,1,1,2,2,2-hexamethyldisilane (1450-14-2) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
In 1,2-dimethoxyethane for 12h; Ambient temperature;	A 85% B 80%

benzophenone (119-61-9) + triphenylsilylkalium (15487-82-8, 6735-25-7) → hexaphenyldisilane (1450-23-3) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
In 1,2-dimethoxyethane for 12h; Ambient temperature;	A 79% B 85%

Cyclohexa-1,2,4-trienyl-phenyl-methanone → tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
samarium(III) chloride In various solvent(s) at 20℃; electrolysis, Al anode;	85%

benzophenone (119-61-9) + carbon dioxide (124-38-9) → 1,1-Diphenylmethanol (91-01-0) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With cadmium(II) sulphide; triethylamine In N,N-dimethyl-formamide at 20℃; for 2h; Irradiation;	A 0% B 85%
With cadmium(II) sulphide; triethylamine In N,N-dimethyl-formamide at 20℃; for 2h; Irradiation;	A 78% B 3%

benzophenone (119-61-9) + 3,4-isopropylidenedioxy-Δ1-pyrroline-1-oxide (213598-45-9) → tetraphenylethane-1,2-diol (464-72-2) + (3aS,4R,6aR)-4-(hydroxydiphenylmethyl)-2,2-dimethyl-tetrahydro-[1,3]dioxolo[4,5-c]pyrrol-5-ol (1384970-76-6)

Conditions	Yield
With samarium diiodide; water In tetrahydrofuran at -78℃; for 2h; Inert atmosphere; diastereoselective reaction;	A 10% B 85%

benzophenone (119-61-9) → 1-deuteriodiphenylmethanol (17498-07-6) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With water-d2; magnesium; ethylene dibromide In tetrahydrofuran at 70℃; for 2h; Catalytic behavior; Reagent/catalyst; Inert atmosphere; Schlenk technique;	A 83% B 12%

benzophenone (119-61-9) + 1-Methoxy-1-(tert-butyldimethylsiloxy)-2-phenylcyclopropane → tetraphenylethane-1,2-diol (464-72-2) + meso-3,4-diphenyladipic acid dimethyl ester (7028-47-9) + Methyl 4-hydroxy-3,4,4-triphenylbutanoate

Conditions	Yield
With magnesium(II) perchlorate; water In acetonitrile at -40℃; Irradiation;	A 9% B 8% C 78%

benzophenone (119-61-9) + methyl 2-oxopyrrolidine-1-carboxylate (26407-91-0) → tetraphenylethane-1,2-diol (464-72-2) + methyl 2-(diphenylmethylene)pyrrolidine-1-carboxylate (1365921-07-8) + C19H21NO4 (1365921-23-8)

Conditions	Yield
Stage #1: benzophenone; methyl 2-oxopyrrolidine-1-carboxylate With titanium tetrachloride; zinc In tetrahydrofuran at 0℃; for 12h; McMurry reaction; Stage #2: With hydrogenchloride In tetrahydrofuran; water at 0℃; for 0.25h;	A n/a B 7% C 76%

benzophenone (119-61-9) + 4-(methylamino)-3-penten-2-one (14092-14-9) → tetraphenylethane-1,2-diol (464-72-2) + N-(2,2-diphenyl-2-hydroxyethyl)-4-amino-3-penten-2-one (74783-91-8)

Conditions	Yield
In benzene for 48h; Irradiation;	A 75% B 17%

methanol (67-56-1) + benzophenone (119-61-9) → 1,1-diphenyl-1,2-ethanediol (4217-62-3) + tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With TiO2 P25 at 20℃; for 48h; UV-irradiation; Inert atmosphere;	A 20% B 71%

1,1-Diphenylmethanol (91-01-0) → tetraphenylethane-1,2-diol (464-72-2)

Conditions	Yield
With air; 2,2'-thiobis(2,4-di-tert-butylphenol); triethylamine; copper(l) chloride In tetrahydrofuran at 20℃; for 12h;	68%
With thiobenzoic acid; (4,4'-di-tert-butyl-2,2'-dipyridyl)-bis-(2-phenylpyridine(-1H))-iridium(III) hexafluorophosphate; magnesium sulfate; benzaldehyde In N,N-dimethyl acetamide at 20℃; for 24h; Inert atmosphere; Irradiation;	34%
With acetone; butanone; benzene Sonnenlicht;
With benzophenone; benzene Sonnenlicht;
With benzene Sonnenlicht;

benzophenone (119-61-9) + 1-Methoxy-1-(tert-butyldimethylsiloxy)-2-phenylcyclopropane → tetraphenylethane-1,2-diol (464-72-2) + meso-3,4-diphenyladipic acid dimethyl ester (7028-47-9) + 4,5,5-triphenyldihydrofuran-2(3H)-one (57697-68-4) + Methyl 4-hydroxy-3,4,4-triphenylbutanoate

Conditions	Yield
With magnesium(II) perchlorate; water In acetonitrile for 10h; Product distribution; Mechanism; Ambient temperature; Irradiation; other times, temperature; also under anhydrous conditions in the presence or absence of naphthalene; also for other cyclopropanone acetals and carbonyl compounds;	A 24% B 9% C 3% D 67%

2-Cyanopyridine (100-70-9) + benzophenone (119-61-9) → diphenyl(2-pyridyl)methanol (19490-90-5) + tetraphenylethane-1,2-diol (464-72-2) + [2,4']Bipyridinyl-2'-yl-diphenyl-methanol (74439-11-5)

Conditions	Yield
In water; isopropyl alcohol for 17h; Product distribution; Mechanism; Irradiation;	A 64% B 0.6 g C 2%
In water; isopropyl alcohol for 17h; Irradiation;	A 64% B 0.6 g C 2%

benzophenone (119-61-9) + trimethyl(allyl)stannane (762-73-2) → tetraphenylethane-1,2-diol (464-72-2) + 1,1-diphenyl-3-buten-1-ol (4165-79-1)

Conditions	Yield
In acetonitrile for 5h; Mechanism; Irradiation; other aromatic carbonyl compounds also investigated;	A 10% B 64%
In acetonitrile for 5h; Irradiation;	A 10% B 64%

N-[1-morpholino(benzyl)] benzamide (22027-65-2) + benzophenone (119-61-9) → 3-(diphenylhydroxymethyl)morpholine (26581-79-3) + tetraphenylethane-1,2-diol (464-72-2) + 1,1,2-triphenyl-1-hydroxy-N-benzoylaminoethane (860522-56-1) + (+/-)-N,N'-dibenzoyl-1,2-diphenyl-1,2-diaminoethane (880141-47-9)

Conditions	Yield
In benzene at 30℃; for 4h; Irradiation; uranium filter;	A n/a B n/a C 63% D 5%

benzophenone (119-61-9) → 3-(diphenylhydroxymethyl)morpholine (26581-79-3) + tetraphenylethane-1,2-diol (464-72-2) + 1,1,2-triphenyl-1-hydroxy-N-benzoylaminoethane (860522-56-1) + (+/-)-N,N'-dibenzoyl-1,2-diphenyl-1,2-diaminoethane (880141-47-9)

Conditions	Yield
With N-[1-morpholino(benzyl)] benzamide In benzene at 30℃; for 4h; Irradiation; uranium filter;	A n/a B n/a C 63% D 5%

benzophenone (119-61-9) → di-tert-butylacetylene (17530-24-4) + tetraphenylethane-1,2-diol (464-72-2) + 4,4-Dimethyl-2-pentinsaeure-tert-butylester (83747-02-8) + 1,5,6-Tri-tert-butyl-3,3-diphenyl-2-oxabicyclo<2.2.0>hex-5-en-4-carbonsaeure-tert-butylester (86260-40-4)

Conditions	Yield
With C21H36N2O2 In pentane for 18h; Ambient temperature; Irradiation;	A n/a B 51% C 61% D 7%

tetraphenylethane-1,2-diol (464-72-2) → benzopinacolone (466-37-5)

Conditions	Yield
With tellurium tetrachloride In dichloromethane Ambient temperature;	100%
With toluene-4-sulfonic acid solid/solid reaction;	100%
o-benzenedisulfonimide In toluene at 110℃; for 7h; Pinacol rearrangement;	100%

tetraphenylethane-1,2-diol (464-72-2) → benzophenone (119-61-9)

Conditions	Yield
With N-Bromosuccinimide; triphenylbismuthane; potassium carbonate In water; acetonitrile for 2h; Ambient temperature;	100%
With naphthalene-1,4-dicarbonitrile; oxygen for 90h; Irradiation;	100%
With dinitrogen tetraoxide; ferric nitrate In ethyl acetate Heating; further oxidizing agent;	100%

tetraphenylethane-1,2-diol (464-72-2) + μ-Oxo-I,I'-bis(trifluoroacetato-O)-I,I'-diphenyldiiodine(III) (91879-79-7) → benzophenone (119-61-9)

Conditions	Yield
In chloroform for 24h; Product distribution; Ambient temperature; various substrates;	99%

tetraphenylethane-1,2-diol (464-72-2) → 9,10-diphenylphenanthrene (602-15-3)

Conditions	Yield
With trifluorormethanesulfonic acid In benzene for 12h; Ambient temperature;	99%
With trifluorormethanesulfonic acid In benzene for 12h; Mechanism; Ambient temperature; other functionalised pinacols;	99%
With trifluorormethanesulfonic acid In benzene at 10 - 20℃; for 20h;	75%
With trifluorormethanesulfonic acid In toluene at 0 - 20℃; for 24h; Pinacol Rearrangement; Inert atmosphere;	74%
Multi-step reaction with 2 steps 1: SOCl2, Py / CH2Cl2 2: methanol / Irradiation View Scheme

[Hf(meso-tetra-p-tolylporphyrin)(OCMe2CMe2O)] + tetraphenylethane-1,2-diol (464-72-2) → [Hf(meso-tetra-p-tolylporphyrin)(OC(Ph)2C(Ph)2O)]

Conditions	Yield
In benzene-d6 for 1 h;	99%

tetraphenylethane-1,2-diol (464-72-2) → 2-chloro-4,4',5,5'-tetraphenyl-1,3,2-dioxaphospholane (1033130-16-3)

Conditions	Yield
With triethylamine; phosphorus trichloride In tetrahydrofuran at -40 - 20℃; Schlenk technique;	99%
With triethylamine; phosphorus trichloride In tetrahydrofuran at -40 - 20℃;

tetraphenylethane-1,2-diol (464-72-2) + isobutyraldehyde (78-84-2) → benzophenone (119-61-9) + 3-Methyl-1,1-diphenyl-1,2-butanediol (74031-77-9)

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 99%

2-Ethylbutyraldehyde (97-96-1) + tetraphenylethane-1,2-diol (464-72-2) → benzophenone (119-61-9) + 3-ethyl-1,1-diphenylpentane-1,2-diol

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 99%

tetraphenylethane-1,2-diol (464-72-2) + cyclohexanecarbaldehyde (2043-61-0) → benzophenone (119-61-9) + 1,1-diphenyl-2-cyclohexylethanediol (20805-08-7)

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 99%

tetraphenylethane-1,2-diol (464-72-2) + 2-Pentanone (107-87-9) → benzophenone (119-61-9) + 2-methyl-1,1-diphenylpentane-1,2-diol

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 99%

tetraphenylethane-1,2-diol (464-72-2) + 4-methyl-2-pentanone (108-10-1) → benzophenone (119-61-9) + 2,4-dimethyl-1,1-diphenylpentane-1,2-diol

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 99%

tetraphenylethane-1,2-diol (464-72-2) + cyclohexanone (108-94-1) → benzophenone (119-61-9) + 1--1-cyclohexanol (15015-46-0)

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 99%

tetraphenylethane-1,2-diol (464-72-2) + acetophenone (98-86-2) → benzophenone (119-61-9) + 1,1,2-triphenyl-1,2-propanediol (3784-22-3)

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 99%

tetraphenylethane-1,2-diol (464-72-2) + isovaleraldehyde (590-86-3) → benzophenone (119-61-9) + 4-methyl-1,1-diphenylpentane-1,2-diol (153595-52-9)

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 98%

tetraphenylethane-1,2-diol (464-72-2) + benzaldehyde (100-52-7) → benzophenone (119-61-9) + 1,1,2-triphenyl-1,2-ethanediol (6296-95-3)

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 98%

tetraphenylethane-1,2-diol (464-72-2) + 4-methyl-benzaldehyde (104-87-0) → benzophenone (119-61-9) + 1,1-diphenyl-2-p-tolylethane-1,2-diol (110247-82-0)

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 98%

4-tert-Butylbenzaldehyde (939-97-9) + tetraphenylethane-1,2-diol (464-72-2) → benzophenone (119-61-9) + 2-(4-tert-butylphenyl)-1,1-diphenylethane-1,2-diol

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 98%

tetraphenylethane-1,2-diol (464-72-2) + 1-phenyl-acetone (103-79-7) → benzophenone (119-61-9) + 2-methyl-1,1,3-triphenylpropane-1,2-diol (412018-01-0)

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 98%

tetraphenylethane-1,2-diol (464-72-2) + cyclopentanone (120-92-3) → benzophenone (119-61-9) + 1-(diphenylhydroxymethyl)-1-hydrohycyclopentane (16177-38-1)

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 98%

(E)-3-phenylpropenal (14371-10-9) + tetraphenylethane-1,2-diol (464-72-2) → benzophenone (119-61-9) + (E)-1,2-dihydroxy-1,1,4-triphenylbut-3-ene

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 97%

tetraphenylethane-1,2-diol (464-72-2) + 1-phenyl-propan-1-one (93-55-0) → benzophenone (119-61-9) + 1,1,2-triphenylbutane-1,2-diol

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 97%

tetraphenylethane-1,2-diol (464-72-2) + chloroacetone (78-95-5) → benzophenone (119-61-9) + 3-chloro-2-methyl-1,1-diphenylpropane-1,2-diol

Conditions	Yield
With titanium(IV) tetrabutoxide; triethylsilyl chloride In dichloromethane at 20℃;	A n/a B 97%

Upstream product

• 553-90-2 Dimethyl oxalate 
• 93-58-3 benzoic acid methyl ester 
• 1603-79-8 phenylglyoxylic acid ethyl ester 
• 71-23-8 propan-1-ol 
• 119-61-9 benzophenone 
• 849585-22-4 LACTIC ACID 
• 91-01-0 1,1-Diphenylmethanol 
• 60-29-7 diethyl ether 
• 693-25-4 n-pentylmagnesium bromide 
• 64-17-5 ethanol 
• 110-54-3 hexane 
• 78-83-1 2-methyl-propan-1-ol 
• 111-70-6 n-heptan1ol 
• 598-01-6 4-methylheptan-4-ol 

Downstream Products

• 15015-46-0 1--1-cyclohexanol 
• 119-61-9 benzophenone 
• 91-01-0 1,1-Diphenylmethanol 
• 470-35-9 tetraphenyloxirane 
• 53484-85-8 pentaphenyl-1,3,2-dioxaborolane 
• 34737-62-7 benzopinacol sulfite 
• 1620-30-0 diphenyl(pyridin-4-yl)methanol 
• 74439-10-4 7-Oxa-2-azabicyclo<3.2.1>-6,6-diphenyloctan-3-one 
• 19490-90-5 diphenyl(2-pyridyl)methanol 
• 102102-32-9 1,1,2,2-Tetraphenyl-ethane-1,2-diol; compound with 2-methyl-quinoline 
• 75458-19-4 3',4'-Dihydro-1'H-[2,4']biquinolinyl-2'-one 
• 132548-97-1 2-(α-Hydroxydiphenylmethyl)pyridine-4-carbonitrile 
• 132907-27-8 2,4-Bis(α-hydroxydiphenylmethyl)pyridine 
• 83242-12-0 1,2-dihydro-1,4-naphthalenedicarbonitrile 

Relevant academic research and scientific papers

Visible-Light Induced Photofixation of CO2 into Benzophenone Catalyzed by Colloidal CdS Microcrystallites

Photocatalytic fixation of CO2 into benzophenone has been achieved under λ > 400-nm light irradiation of a CO2-saturated DMF solution of colloidal CdS microcrystallites as photocatalysts, triethylamine as a sacrificial electron donor, and benzophenone yielding benzilic acid with benzhydrol and benzopinacol.

Chemical reactions of benzophenone photoirradiated in 1,2-polybutadiene

The photolysis of benzophenone (BP) in 1,2-polybutadiene (1,2PB) was studied at low radiation intensity in order to clarify some aspects of BP photochemistry and of 1,2PB photocrosslinking. The expected primary photoreactions of hydrogen abstraction and c

Interaction between alkali metal aromatic ketone radical anions and the chlorides of lithium and magnesium in solution. A case of a carbon-carbon bond strengthening through complex formation

The interaction between lithium, sodium and potassium salts with the pre-formed radical anions of benzophenone, 2-methylbenzophenone, 2,4,6-trimethylbenzophenone or fluorenone, and lithium or magnesium chlorides has been studied by nuclear magnetic resona

Rate-Determining Step of the Reactions of Benzophenone with Various Grignard Reagents

Carbonyl carbon kinetic isotope effects (KIEs) have been determined for the reaction of benzophenone-7-(14)C with various Grignard reagents at 0 deg C.The observed KIEs are as follows: MeMgI/Et2O, 12k/14k = 1.056 +/- 0.002; MeMgBr/Et2O, 1.050 +/- 0.011; MeMgBr/THF, 1.056 +/- 0.004; PhMgBr/Et2O, 1.056 +/- 0.004; o-CH3C6H4MgBr/Et2O, 1.060 +/- 0.014; CH2=CHCH2MgBr/Et2O, 0.999 +/- 0.003; CH3CH=CHCH2MgBr/Et2O, 0.999 +/- 0.002; PhCH2MgBr/Et2O, 1.024 +/- 0.007; t-BuMgCl/Et2O, 1.010 +/- 0.007, 1.004 +/- 0.004; MeMgI + 5 mol percent FeCl3/Et2O, 1.063 +/- 0.033 (for 1,2-adduct formation), 0.997 +/- 0.019 (for pinacol formation).The relative reactivities of ortho-, meta-, and para-substituted benzophenones with these reagents were also determined by competition experiments.The reactions can be classified into three groups on the basis of these results: the first group gives a large (14)C KIE, a medium-sized Hammett ρ value, and a large steric rate retardation due to ortho substituents; the second gives a KIE of unity, a near-zero ρ value, and no steric rate retardation; and the third gives a small (14)C KIE, a large ρ value, and no steric rate retardation.It was concluded that the intimate mechanism of these Grignard reactions is diffrent although they all follow the single-electron-transfer (SET) scheme; specifically, the rate-determining step for MeMgX, ArMgBr, and PhCH2MgBr is C-C bond formation while that for allylic reagents is initial SET.The rate-determining step for t-BuMgCl is the isomerization of the radical ion pair intermediate.

Reduction of Crystal Violet by Diphenylketyl Radicals

Crystal violet (CV+) is stable to direct photolysis in acetonitrile at λirr >/= 366 nm even in the presence of hydrogen donors (benzhydrol and 2-propanol).However, when benzophenone (K) is present in samples containing hydrogen donor and λirr + by diphenylketyl (KH.) followed by hydrogen transfer to the intermediate CV. with formation of the leuco dye (CVH) is proposed.The rate constant (k6) for the electron transfer reaction CV+ + KH. -> CV. + K + H+, k6 = 6 +/- 2 x 105 M-1 s-1 (6) has been determined by two methods both of which rely on the competition between reactions 5 and 6 2KH. -> K2H2, k5 = 1.05 +/- 0.02 x 108 M-1 s-1 (5) In the first the quantum yield of sensitized fading is determined as a function of CV+ concentration.In the second the rates of benzpinacol formation in the absence and presence of CV+ are followed.

Visible-light Induced Photocatalytic Fixation of CO2 into Benzophenone Using Poly(p-phenylene) as a Photocatalyst

Photoreductive fixation of CO2 into benzophenone can be achieved in a CO2-saturated DMF solution by using poly(p-phenylene) as a heterogeneous photocatalyst and triethylamine as an electron donor.The presence of quaternary ammonium salts increases the yield of benzylic acid as a CO2-photofixed product from benzophenone.

EFFECT OF THE SOLVENT ON REDUCTION OF AZOMETHINE DYES WITH KETYL RADICALS AND RECOMBINATION OF KETYL RADICALS

The rate constants of transfer of a hydrogen atom from ketyl radicals to azomethine dyes (kH) and the rate constants of recombination of ketyl radicals (2kr) in different solvents were measured by the method of pulsed photolysis.The dependences of kH and 2kr on the polarity of the solvent are V-shaped: kH and 2kr are maximum in weakly solvating solvents and in water and are minimum in nucleophilic solvents of medium polarity.This is due to the fact that nucleophilic solvation decreases and electrophilic solvation increases the reactivity of the ketyl radicals.

Photochemical Cycloaddition of Benzophenone to 7-Methylenetetracyclo2,8.04,6>octan-3-one and its Alcohol Derivative

Irradiation of benzophenone with 2,4-dimethyl- or 1,2,4-trimethyl-7-methylenetetracyclo2,8.04,6>octan-3-one affords oxetans (3a) and (3b), respectively, while irradiation with the alcohol derivative (2) affords a rearranged product (5) in addition to an oxetan.

Visible light-induced photofixation of CO2 into benzophenone: Roles of poly(p-phenylene) as photocatalyst and two-electron mediator in the presence of quaternary onium salts

Visible light-induced photocatalytic fixation of CO2 into benzophenone (1) has been carried out in CO2-saturated DMF (N,N-dimethylformamide) using poly(p-phenylene) (PPP) as a heterogeneous photocatalyst and triethylamine as an electron donor. Diphenylglycolic acid (2) is produced as a CO2-fixed product together with benzhydrol (3), benzopinacol (4) and 1,1-diphenylpropane-1,2-diol (5). The presence of quaternary onium salts such as tetraethylammonium chloride (Et4NCl) increases the yield of 2 in the presence of CO2 and those of 3 and 5 in the absence of CO2. The soft onium cations from quaternary onium salts are proposed to stabilize diphenylcarbinol anion (9) as a common precursor of 2, 3 and 5 on the basis of the HSAB concept. Further, the enhanced formation of PPP dianions (7) through PPP radical anions (6) has been examined in the reduction of PPP with sodium metal in the presence of Et4NCl. Photocatalysis of PPP in the CO2 fixation is discussed in terms of onium salt effects and favorable photoformation of 6 and 7 as an electron pool in the presence of quaternary onium cations.

Ultrasound effects on the photopinacolization of benzophenone

Ultrasonic irradiation is able to modify the course of several photochemical reactions, especially bimolecular, proceeding via triplet states. These effects were illustrated in the study of benzophenone photopinacolization in ethanol. The rates and yields increase when sonication is applied simultaneously to UV irradiation. An explanation is based on a 2-fold effect: (i) light-absorbing transient species undergo sonolytic decomposition, making the photoconversion more efficient, and (ii) sonication induces the triplet state quenching, as shown by Stern-Volmer plots from experiments run in the presence of naphthalene, probably due to the easier collisional deactivation processes favored by the homogeneous distribution of the activated species.