262-12-4

Basic information

• Product Name: DIBENZO-P-DIOXIN
• Synonyms: ai308911;dibenzo(1,4)dioxin;Dibenzo[1,4]dioxin;Dibenzodioxin;dibenzo-para-dioxin;Diphenylene dioxide;diphenylenedioxide;NCI-C03656
• CAS NO: 262-12-4
• Molecular Formula: C₁₂H₈O₂
• Molecular Weight: 184.19
• EINECS: 205-974-2
• Mol File: 262-12-4.mol
• Article Data: 30

Chemical Properties

• Melting Point: 120 °C
• Boiling Point: 278.5°C
• Flash Point: 115.7°C
• Appearance: white crystalline solid
• Density: 1.2430
• Vapor Pressure: 0.0072mmHg at 25°C
• Refractive Index: 1.6250 (estimate)
• Storage Temp.: Sealed in dry,Room Temperature
• Water Solubility: 1.4mg/L(25 oC)
• Stability: Stable. Combustible. Incompatible with strong oxidizing agents.
• CAS DataBase Reference: DIBENZO-P-DIOXIN(CAS DataBase Reference)
• NIST Chemistry Reference: DIBENZO-P-DIOXIN(262-12-4)
• EPA Substance Registry System: DIBENZO-P-DIOXIN(262-12-4)

Safety Data

• Hazard Codes: Xn,N
• Statements: 22-51/53
• Safety Statements: 61
• RIDADR: 3077
• WGK Germany: 3
• RTECS: HP3090000
• HazardClass: 9
• PackingGroup: I
• Hazardous Substances Data: 262-12-4(Hazardous Substances Data)

Usage

Chemical Properties

white crystalline solid

Uses

Dibenzo-?p-?dioxin is a standard used in environmental testing and research as well as in the studying of PCBs, PCDDs and PCDFs in food.

Synthesis Reference(s)

Synthetic Communications, 13, p. 335, 1983 DOI: 10.1080/00397918308066985

General Description

White crystals or crystalline solid.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

DIBENZO-P-DIOXIN is an ether. Ethers may react violently with strong oxidizing agents. In other reactions, which typically involve the breaking of the carbon-oxygen bond, ethers are relatively inert.

Fire Hazard

Flash point data for DIBENZO-P-DIOXIN are not available. DIBENZO-P-DIOXIN is probably combustible.

InChI:InChI=1/C12H8O2/c1-2-6-10-9(5-1)13-11-7-3-4-8-12(11)14-10/h1-8H

Synthetic route

2-chlorodibenzo-p-dioxin (39227-54-8) → dioxin (262-12-4)

Conditions	Yield
With acetophenone In methanol at 20℃; for 0.166667h; Irradiation;	95.7%

2,7-dichloro-dibenzo[1,4]dioxine (33857-26-0) → dioxin (262-12-4)

Conditions	Yield
With sodium hydroxide; palladium on activated charcoal In isopropyl alcohol at 30℃; for 3h;	94.4%
Multi-step reaction with 2 steps 1: 40.2 percent / acetophenone / methanol / 1 h / 20 °C / Irradiation 2: 95.7 percent / acetophenone / methanol / 0.17 h / 20 °C / Irradiation View Scheme
Multi-step reaction with 2 steps 1: 40.2 percent / acetophenone / methanol / 1 h / 20 °C / Irradiation 2: 11.6 percent / methanol / 0.08 h / 20 °C / Irradiation View Scheme

η6-dibenzodioxin-η5-cyclopentadienyliron hexafluorophosphate → dioxin (262-12-4)

Conditions	Yield
at 200 - 250℃; under 1 Torr; for 1h;	91%

2-hydroxybromobenzene (95-56-7) → dioxin (262-12-4)

Conditions	Yield
With potassium carbonate at 120℃; for 12h; Ullmann Condensation;	90%
With pyridine; copper(I) phenylacetylenide 1.) reflux, 5 h, 2.) reflux, 5 h; Yield given. Multistep reaction;

1-chlorodibenzo-p-dioxin (39227-53-7) → dioxin (262-12-4)

Conditions	Yield
With acetophenone In methanol at 20℃; for 3h; Irradiation;	87.4%

hexachloroantimonate of the dibenzo-p-dioxin radical-cation → dioxin (262-12-4)

Conditions	Yield
With zinc In acetonitrile for 0.166667h; Product distribution;	86%

2,3,7,8-Tetrachloro-dibenzo[1,4]dioxine (1746-01-6) → dioxin (262-12-4)

Conditions	Yield
With potassium tert-butylate; isopropyl alcohol In N,N-dimethyl-formamide at 20℃; for 48h; UV-irradiation;	83%
With borane-ammonia complex In water; isopropyl alcohol at 50℃; for 5h; Sealed tube;	92 %Chromat.

2,3-dichloro-dibenzo[1,4]dioxine (29446-15-9) → dioxin (262-12-4)

Conditions	Yield
With potassium tert-butylate; isopropyl alcohol In N,N-dimethyl-formamide at 20℃; for 48h; UV-irradiation;	81%
Multi-step reaction with 2 steps 1: 55.9 percent / acetophenone / methanol / 3 h / 20 °C / Irradiation 2: 95.7 percent / acetophenone / methanol / 0.17 h / 20 °C / Irradiation View Scheme
Multi-step reaction with 2 steps 1: 55.9 percent / acetophenone / methanol / 3 h / 20 °C / Irradiation 2: 11.6 percent / methanol / 0.08 h / 20 °C / Irradiation View Scheme
Multi-step reaction with 2 steps 1: 24.3 percent / methanol / 0.17 h / 20 °C / Irradiation 2: 95.7 percent / acetophenone / methanol / 0.17 h / 20 °C / Irradiation View Scheme
Multi-step reaction with 2 steps 1: 24.3 percent / methanol / 0.17 h / 20 °C / Irradiation 2: 11.6 percent / methanol / 0.08 h / 20 °C / Irradiation View Scheme

1,2,6,7-tetrachlorodioxine (40581-90-6) → dioxin (262-12-4)

Conditions	Yield
With sodium hydroxide; palladium on activated charcoal In isopropyl alcohol at 23℃; for 3h;	74.1%

2-trimethylsilyldibenzo<1,4>dioxin (139458-06-3) + acetyl chloride (75-36-5) → dioxin (262-12-4) + 2-acetyldibenzo<1,4>dioxin (22693-98-7)

Conditions	Yield
With aluminium trichloride for 1h; Heating;	A 56% B 36%

2,3-dichloro-dibenzo[1,4]dioxine (29446-15-9) → dioxin (262-12-4) + 2-chlorodibenzo-p-dioxin (39227-54-8)

Conditions	Yield
With acetophenone In methanol at 20℃; for 3h; Irradiation;	A 19.9% B 55.9%

2-monochlorophenol (95-57-8) → dioxin (262-12-4)

Conditions	Yield
With Tris(3,6-dioxaheptyl)amine; potassium carbonate; copper(l) chloride In diethylene glycol dimethyl ether for 19h; Heating;	50%
With copper; potassium carbonate at 170 - 180℃;	45%
With copper; potassium carbonate at 180℃;
With potassium hydroxide; copper at 184.85℃; for 4h;

benzene-1,2-diol (120-80-9) + (η5-2,4-cyclopentadien-1-yl)(η6-1,2-dichlorobenzene)iron(1+) hexafluorophosphate(1-) → dioxin (262-12-4) + 2-chlorophenyl 2-hydroxyphenyl ether (21567-19-1)

Conditions	Yield
With potassium carbonate In tetrahydrofuran for 22h; Heating;	A 50% B 36%

2,7-dichloro-dibenzo[1,4]dioxine (33857-26-0) → dioxin (262-12-4) + 2-chlorodibenzo-p-dioxin (39227-54-8)

Conditions	Yield
With acetophenone In methanol at 20℃; for 1h; Irradiation;	A 49.1% B 40.2%

benzene-1,2-diol (120-80-9) + 1,2-Dinitrobenzene (528-29-0) → dioxin (262-12-4)

Conditions	Yield
Stage #1: benzene-1,2-diol With potassium In N,N,N,N,N,N-hexamethylphosphoric triamide at 20℃; Inert atmosphere; Stage #2: 1,2-Dinitrobenzene In N,N,N,N,N,N-hexamethylphosphoric triamide at 110℃; for 4h;	41%
With potassium 1) HMPA, 20 deg C; 2) 110 deg C, 4 h; Yield given. Multistep reaction;

2-chlorodibenzo-p-dioxin (39227-54-8) + carbon dioxide (124-38-9) → dioxin (262-12-4) + dibenzo<1,4>dioxin-2-carboxylic acid (17054-75-0)

Conditions	Yield
With tetrabutylammomium bromide In N,N-dimethyl-formamide at -5 - 0℃; Dehalogenation; Carboxylation; Electrochemical reaction;	A 2% B 21%

1,2-Diiodobenzene (615-42-9) + benzene-1,2-diol (120-80-9) → dioxin (262-12-4)

Conditions	Yield
With copper(l) iodide; iron(III)-acetylacetonate; potassium carbonate In dimethyl sulfoxide at 110℃; for 168h; Ullmann Condensation; Inert atmosphere;	18%

2-chlorodibenzo-p-dioxin (39227-54-8) → 5-chloro-[1,1'-biphenyl]-2,2'-diol + dioxin (262-12-4)

Conditions	Yield
In methanol at 20℃; for 0.0833333h; Irradiation;	A 16.6% B 11.6%

2-hydroxybromobenzene (95-56-7) → dibenzofuran (132-64-9) + 4-bromodibenzofuran (89827-45-2) + dioxin (262-12-4) + 4,6-dibromodibenzo-[b,d]furan (201138-91-2)

Conditions	Yield
With oxygen at 650℃; under 760 Torr; for 0.000555556h; Product distribution; Further Variations:; Temperatures;	A 0.9% B 0.82% C 16.6% D 2.4%

2-monochlorophenol (95-57-8) → dioxin (262-12-4) + 2,6-Dichlorophenol (87-65-0) + 1-chlorodibenzo-p-dioxin (39227-53-7) + 4,6-dichlorodibenzofuran

Conditions	Yield
With oxygen at 600℃; for 0.000555556h; Product distribution; Further Variations:; Temperatures;	A 1.32% B 0.59% C 0.92% D 9.43%

2-hydroxybromobenzene (95-56-7) → dibenzofuran (132-64-9) + 4-bromodibenzofuran (89827-45-2) + dioxin (262-12-4) + phenol (108-95-2)

Conditions	Yield
at 600℃; under 760 Torr; for 0.000555556h; Product distribution; Further Variations:; Temperatures; Pyrolysis;	A 0.17% B 0.05% C 5.96% D 0.36%

2-monochlorophenol (95-57-8) → dioxin (262-12-4) + 2,6-Dichlorophenol (87-65-0) + 1-chlorodibenzo-p-dioxin (39227-53-7) + 2,4-dichlorophenol (120-83-2)

Conditions	Yield
With oxygen; silica gel; copper dichloride at 400℃; Product distribution; Further Variations:; Temperatures;	A 0.6915% B 0.219% C 0.7511% D 0.238%
With oxygen; silica gel; copper dichloride at 350℃; Formation of xenobiotics; Further byproducts.;	A 0.0672% B 0.229% C 0.3293% D 0.282%

phenol (108-95-2) → dibenzofuran (132-64-9) + dioxin (262-12-4) + 2-monochlorophenol (95-57-8) + 4-chloro-phenol (106-48-9)

Conditions	Yield
With oxygen; silica gel; copper dichloride at 425℃; Product distribution; Further Variations:; Temperatures;	A 0.06% B 0.002% C 0.041% D 0.002%

2,2'-oxydiphenol (15764-52-0) → dioxin (262-12-4)

Conditions	Yield
With phosphorus; hydrogen bromide at 180 - 190℃;

di(2-methoxyphenyl) ether (1655-70-5) → dioxin (262-12-4)

Conditions	Yield
With hydrogen bromide at 170 - 190℃;
Multi-step reaction with 2 steps 1: AlCl3; benzene 2: hydrobromic acid; red phosphorus / 180 - 190 °C View Scheme

sodium 4-chlorophenolate (1193-00-6) → dioxin (262-12-4)

Conditions	Yield
at 250℃; under 4 Torr;

benzene-1,2-diol (120-80-9) → dioxin (262-12-4)

Conditions	Yield
With phosphorus pentoxide at 260℃;
Multi-step reaction with 2 steps 1: sulfuryl dichloride / diethyl ether / 20 °C / Inert atmosphere 2: potassium carbonate / dimethyl sulfoxide / 24 h / 130 °C View Scheme

2-monochlorophenol (95-57-8) → dioxin (262-12-4) + 2-<2-(2-chlorophenoxy)phenoxy>phenol (79807-70-8) + 2-<2-(2-<2-<2-(2-chlorophenoxy)phenoxy>phenoxy>phenoxy)phenoxy>phenol (79807-69-5)

Conditions	Yield
With potassium hydroxide; copper; potassium carbonate 1.) 170-200 deg C, 6 h, 2.) reflux, 3 h; Yield given. Multistep reaction. Yields of byproduct given;
With potassium hydroxide; copper; potassium carbonate 1.) 170-200 deg C, 6 h, 2.) reflux, 3 h, 3.) ethanol, 0 deg C, 16 h; Yield given. Multistep reaction. Yields of byproduct given;

pyrocatechol monosodium salt (34789-97-4) + C6H4Cl2*C3CrO3 → dioxin (262-12-4) + 2-Phenoxyphenol (2417-10-9) + 2-chlorophenyl 2-hydroxyphenyl ether (21567-19-1) + chlorobenzene (108-90-7)

Conditions	Yield
In N,N,N,N,N,N-hexamethylphosphoric triamide at 120℃; for 113h; Product distribution; further temperatures, reaction times and solvents;

sodium catecholate (20244-21-7, 34789-97-4, 51818-64-5, 7664-47-3) + C6H4Cl2*C3CrO3 → dioxin (262-12-4) + chlorobenzene (108-90-7)

Conditions	Yield
In N,N,N,N,N,N-hexamethylphosphoric triamide at 120℃; for 80h; Product distribution; further solvent, temperatures and reaction times;

dioxin (262-12-4) → 2,3,7,8-tetrabromodibenzodioxin (50585-41-6)

Conditions	Yield
With bromine In trifluoroacetic acid for 6h; Heating;	98%
With bromine; trifluoroacetic acid for 6h; Heating;	97%
With bromine; acetic acid

dioxin (262-12-4) → 2,2',3-trihydroxydiphenyl ether (128292-53-5)

Conditions	Yield
With Escherichia coli JM109 harbouring pJ31BP-F275W In dimethyl sulfoxide at 30℃; for 18h; L-medium; Enzymatic reaction;	97.8%
With oxygen; terminal dioxygenase Conversion of starting material; Enzymatic reaction;

phthalic anhydride (85-44-9) + dioxin (262-12-4) → 2-(dibenzo[1,4]dioxin-2-carbonyl)-benzoic acid

Conditions	Yield
Stage #1: phthalic anhydride With aluminum (III) chloride In dichloromethane for 0.5h; Stage #2: dioxin In dichloromethane	96%
With aluminium trichloride; chlorobenzene

dioxin (262-12-4) → 2,7-dinitrodibenzo-p-dioxin (71400-33-4)

Conditions	Yield
With nitric acid In acetic acid at 20℃; for 3h;	96%
With nitric acid; acetic acid	96%
With nitric acid; acetic acid In water at 20℃; for 3h;	96%
With water; nitric acid; acetic acid

dioxin (262-12-4) → 2,3,7,8-tetranitrodibenzo[b,e][1,4]dioxine (52354-40-2)

Conditions	Yield
With nitric acid; acetic anhydride	88%
With nitric acid; trifluoroacetic anhydride at 70℃; Cooling with ice;	73%
With nitric acid; trifluoroacetic anhydride at 70℃; for 1.5h;	73%

dioxin (262-12-4) + N,N-dimethyl-formamide (68-12-2, 33513-42-7) → dibenzo<1,4>dioxin-1-carboxaldehyde (51689-41-9)

Conditions	Yield
With n-butyllithium In tetrahydrofuran; hexane at 25℃; for 0.166667h;	83%
Stage #1: dioxin With n-butyllithium In diethyl ether; hexane at 20℃; for 1h; Stage #2: N,N-dimethyl-formamide In diethyl ether; hexane at 20℃; for 0.166667h;	68%
With n-butyllithium; N,N,N,N,-tetramethylethylenediamine 1) THF, hexane, -30 deg C, 1h; Yield given. Multistep reaction;
With n-butyllithium 1.) THF, hexane, 25 deg C, 1 d, 2.) THF, hexane, from -78 deg C to 25 deg C; Yield given. Multistep reaction;

dioxin (262-12-4) → 2-nitrodibenzo<1,4>dioxin (38178-41-5)

Conditions	Yield
With dinitrogen tetraoxide In acetonitrile for 0.166667h;	71%
With nitric acid; acetic acid at 20℃; for 2h;	50%
With water; nitric acid; acetic acid at 0℃;
With nitrate radical at 23.85℃; under 735 Torr; Kinetics; Nitration;

dioxin (262-12-4) → hexachloroantimonate of the dibenzo-p-dioxin radical-cation

Conditions	Yield
With antimonypentachloride In acetonitrile	71%

phenyl benzyl ketone (451-40-1) + dioxin (262-12-4) → 2-(dibenzo[b,e][1,4]dioxin-2-yl)-1,2-diphenylethan-1-one

Conditions	Yield
With iron(III) chloride; 2,3-dicyano-5,6-dichloro-p-benzoquinone In hexane at 55℃; Inert atmosphere;	70%
With iron(III) chloride; 2,3-dicyano-5,6-dichloro-p-benzoquinone In 1,2-dichloro-ethane at 80℃; Friedel-Crafts Alkylation; Inert atmosphere;	56%

dioxin (262-12-4) → 2-bromodibenzo<1,4>dioxin (105906-36-3)

Conditions	Yield
With 1,4-dioxane dibromide at 95 - 100℃; for 3h;	60%
With carbon disulfide; bromine
With potassium bromate; acetic acid; potassium bromide
With 1,4-dioxane dibromide In 1,4-dioxane at 95 - 100℃; for 3h;

dioxin (262-12-4) + chromium(0) hexacarbonyl (199620-14-9, 13007-92-6) → tricarbonyl{(1,2,3,4,4a,10a,-η)-dibenzo{b,e}{1,4}dioxin}chromium (105888-12-8)

Conditions	Yield
In tetrahydrofuran; dibutyl ether under N2, heated under reflux for 22 h; filtered through Celite, residue washed with Et2O, solvents removed, chromy. (Me2CO/hexane 1:2); elem. anal.;	58%

dioxin (262-12-4) + chloroacetyl chloride (79-04-9) → 1,1′-(dibenzo[b,e][1,4]dioxine-2,7-diyl)bis(2-chloroethanone) (854397-12-9)

Conditions	Yield
With aluminum (III) chloride at -78 - 20℃; for 4h;	50%
With aluminum (III) chloride In dichloromethane at -78 - 20℃; for 4h;	50%
With aluminum (III) chloride In dichloromethane at -78 - 20℃; for 4h;	50%

dioxin (262-12-4) → 2,7-dinitrodibenzo-p-dioxin (71400-33-4) + 2,8-dinitrodiphenylene dioxide (71400-34-5)

Conditions	Yield
With dinitrogen tetraoxide In trifluoroacetic acid for 0.25h; other reagent;	A 50% B 44%
With nitric acid In acetic anhydride at 0℃; for 0.25h;	A 18% B 33%
With water; nitric acid

dioxin (262-12-4) → 2,8-dibromobenzo<1,4>dioxin (105836-96-2)

Conditions	Yield
With 1,4-dioxane dibromide In 1,4-dioxane for 3h; Heating;	30%
With potassium bromate; acetic acid; potassium bromide
With bromine; nitrobenzene
With 1,4-dioxane dibromide In 1,4-dioxane at 95 - 100℃; for 3h;

dioxin (262-12-4) + 3,3',4,4'-tetrahexyloxybiphenyl (161691-13-0) → 2,3,6,7-Tetrakis-hexyloxy-10,15-dioxa-dibenzo[a,c]naphthacene

Conditions	Yield
With iron(III) chloride In dichloromethane for 2h;	25%

Upstream product

• 1193-00-6 sodium 4-chlorophenolate 
• 120-80-9 benzene-1,2-diol 
• 50722-41-3 2,7-dimethoxy-9,10-dihydro-phenanthrene 
• 95-50-1 1,2-dichloro-benzene 
• 95-57-8 2-monochlorophenol 
• 95-56-7 2-hydroxybromobenzene 
• 29446-15-9 2,3-dichloro-dibenzo[1,4]dioxine 
• 39227-53-7 1-chlorodibenzo-p-dioxin 
• 615-42-9 1,2-Diiodobenzene 
• 1655-70-5 di(2-methoxyphenyl) ether 
• 15764-52-0 2,2'-oxydiphenol 
• 89-69-0 2,4,5-Trichloronitrobenzene 
• 3428-24-8 4,5-dichlorocatechol 
• 1746-01-6 2,3,7,8-Tetrachloro-dibenzo[1,4]dioxine 

Downstream Products

• 51689-36-2 dibenzo<1,4>dioxin-1-carboxylic acid 
• 57315-76-1 2-benzoylamino-1-dibenzo[1,4]dioxin-2-yl-ethanone 
• 101937-01-3 2-Benzyl-dibenzo[1,4]dioxin 
• 25500-50-9 dodecahydrooxanthrene 
• 1792-81-0 cis-1,2-cyclohexane 
• 2417-10-9 o-Phenoxyphenol 
• 105908-71-2 1-bromodibenzo[b,e][1,4]dioxine 
• 105906-36-3 2-bromodibenzo<1,4>dioxin 
• 105836-96-2 2,8-dibromobenzo<1,4>dioxin 
• 3487-81-8 2-(2-hydroxy-phenoxy)-benzoic acid 
• 50585-37-0 2,3-dibromodibenzo-p-dioxin 
• 38178-41-5 2-nitrodibenzo<1,4>dioxin 
• 1746-01-6 2,3,7,8-Tetrachloro-dibenzo[1,4]dioxine 
• 50585-41-6 2,3,7,8-tetrabromodibenzodioxin 

Relevant articles and documents

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RADIOLYSIS OF POLYCHLORODIBENZODIOXINS IN HEXANE

In the radiolysis of 2,3,7,8-tetrachlorodibenzodioxin in n-hexane (dose 6.5 Mrad), the degree of its decomposition according to data of chromatography-mass spectrometry is not less than 99.99995 rel. percent (detection limit 2E-10 mass percent).In this case, the less-chlorinated dibenzodioxins formed at lower irradiation doses are not detected.

A detailed mechanism of the surface-mediated formation of PCDD/F from the oxidation of 2-chlorophenol on a CuO/Silica surface

The formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) via a Cu(II)O-mediated reaction of 2-chlorophenol (2-MCP) has been studied in a packed bed reactor over a temperature range of 200-500 °C. Under oxidative conditions, the principle PCDD/F products were 1-monochlorodibenzo-p-dioxin (MCDD) > 4,6-dichlorodibenzofuran (DCDF) > dibenzo-p-dioxin (DD). EPR studies indicated the presence of a carbon-centered phenoxyl radical on the surface, which is attributed to chemisorption of 2-MCP at a copper oxide site followed by electron transfer to Cu(II) to form Cu(I) and a phenoxyl radical. The presence of a surface bound phenoxyl radical and the formation of MCDD, DCDF, and DD, which were also observed as the principle products of the gas-phase oxidation of 2-MCP, strongly suggest a surface-mediated mechanism involving many of the same radical and molecular species involved in the gas-phase formation of PCDD/F from 2-MCP. Reaction orders of 0.5-1.0 were observed for MCDD and DD formation, indicating an Eley-Rideal formation mechanism. Negative reaction orders were observed for DCDF formation, indicating a Langmuir-Hinshelwood formation mechanism. No highly chlorinated PCDFs were observed, suggesting a mechanism in which DCDF is desorbed from the surface before it can undergo additional chlorination. Highly chlorinated PCDDs were observed, which were consistent with a mechanism in which DD remained adsorbed to the surface and underwent additional chlorination. Chloro-o-quinone and chlorocatechol, which are precursors to semiquinone radicals, were also observed products. A detailed reaction mechanism accounting for all reported products is proposed.

Dechlorination of polychlorinated dibenzo-p-dioxins catalyzed by noble metal catalysts under mild conditions

Dechlorination of polychlorinated dibenzo-p-dioxins such as 2,7-dichlorodibenzo-p-dioxin (2,7-DCDD) and 1,2,6,7-tetrachlorodibenzo-p-dioxin (1,2,6,7-TCDD) was carried out in a solution of NaOH in 2-propanol in the presence of carbon-supported noble metal

Hydrogen bonding promoted simple and clean photo-induced reduction of C-X bond with isopropanol

We herein report a simple and clean photo-induced metal-free reduction of C-X bond under an atmosphere of air at room temperature. Isopropanol is used as both the reducing reagent and solvent. Various functional groups (acids, esters, alcohols, anilines, phenols, indoles, pyridines, cyano and trifluoromethyl groups) and other heterocyclic compounds are tolerated. Different organic halides (including C-I, C-Br and C-Cl bonds) can be dehalogenated with moderate to excellent yields. Polyhalides are also reduced chemoselectively and efficiently. DFT calculation suggests a six-membered ring transition state via C-X H-O hydrogen bonding to decrease the activation energy.

Highly active recyclable heterogeneous Pd/ZnO nanoparticle catalyst: Sustainable developments for the C-O and C-N bond cross-coupling reactions of aryl halides under ligand-free conditions

Efficient Pd supported on ZnO nanoparticles for the ligand-free O-arylation and N-arylation of phenols and various N-H heterocycles with aryl chlorides, bromides, and iodides were readily synthesized and characterized. The amount of palladium on ZnO is 9.84 wt% (0.005 g of the catalyst contains 462 × 10-8 mol% of Pd) which was determined by ICP analysis. This nano sized Pd/ZnO with an average particle size of 20-25 nm and specific surface area 40.61 m2 g-1 was used as a new reusable heterogeneous catalyst for the formation of C-O and C-N bonds in organic synthesis. This protocol gives the arylated product in satisfactory yields without any N2 or Ar flow. The catalyst can be recovered and recycled several times without marked loss of activity.