193469-78-2

Basic information

• Product Name: benzyne
• CAS NO: 193469-78-2
• Molecular Weight: 76.0978
• Mol File: 193469-78-2.mol

Chemical Properties

• CAS DataBase Reference: benzyne(CAS DataBase Reference)
• NIST Chemistry Reference: benzyne(193469-78-2)
• EPA Substance Registry System: benzyne(193469-78-2)

Safety Data

• Hazardous Substances Data: 193469-78-2(Hazardous Substances Data)

Upstream product

• 6383-11-5 benzocyclobutene-1,2-dione 
• 85-44-9 phthalic anhydride 
• 1488-42-2 Diphenyliodonium-2-carboxylate 
• 591-50-4 iodobenzene 
• 1608-42-0 benzenedizolium-2-carboxylate 
• 4733-52-2 phthaloyl peroxide 
• 118-92-3 anthranilic acid 
• 462-06-6 fluorobenzene 
• 1239886-72-6 [[MeC(N(2,6-ⁱPr₂C₆H₃))CHC(Me)(NCH₂CH₂NMe)]Sc=N(2,6-ⁱPr₂C₆H₃)(DMAP)] 
• 100-66-3 methoxybenzene 
• 108-86-1 bromobenzene 
• 108-90-7 chlorobenzene 
• 1072-85-1 o-fluorobromobenzene 
• 164594-13-2 Phenyl[2-(trimethylsilyl)phenyl]iodonium trifluoromethanesulfonate 

Downstream Products

• 37755-73-0 1,2,3,4,9-pentaphenyl-1,4-dihydro-1,4-epiphosphano-naphthalene 9-oxide 
• 54400-55-4 2-phenyl-4λ⁴-benzo[3,4][1,2]dithiolo[1,5-b][1,2,4]dithiazole 
• 95-15-8 Benzo[b]thiophene 
• 13131-19-6 (1R,8S)-9-Methyl-9-aza-tricyclo[6.2.2.0^2,7]dodeca-2,4,6,11-tetraen-10-one 
• 13131-19-6 (1S,8R)-9-Methyl-9-aza-tricyclo[6.2.2.0^2,7]dodeca-2⁽⁷⁾,3,5,11-tetraen-10-one 
• 83021-73-2 (1S,8S)-8,9-Dimethyl-11-phenyl-9-aza-tricyclo[6.2.2.0^2,7]dodeca-2,4,6,11-tetraen-10-one 
• 83021-73-2 (1R,8R)-8,9-Dimethyl-11-phenyl-9-aza-tricyclo[6.2.2.0^2,7]dodeca-2⁽⁷⁾,3,5,11-tetraen-10-one 
• 1499-10-1 9,10-diphenylanthracene 
• 169560-87-6 3,3-diphenyl-3H-indazole 
• 197780-83-9 2-methyl-5-(9-triptycyl)benzaldehyde 
• 2379-55-7 2,3-dimethylquinoxaline 
• 6187-89-9 3-methyl-1,2-benzisothiazole 
• 75-05-8 acetonitrile 
• 51787-74-7 1-methyl-3-phenyl-isoquinolin-4-ol 

Relevant articles and documents

DETECTION BY INFRARED SPECTROSCOPY OF BENZYNE FORMED BY FLASH VACUUM PYROLYSIS AND TRAPPED IN AN ARGON MATRIX

Benzyne has been detected in the argon matrices obtained from pyrolyses of isobenzofuran-1,3-dione (1), 2,3-benzodioxin-1,4-dione (2), benzocyclobutenedione (3), 2,2-dimethyl-5-(octahydro-1',2',4'-methano-3'H-cyclobutapentalen-3'-ylidene)-1,3-dioxan-4,6-dione (8) and 5,5'-(pentacyclo2,6.04,10.05,8>decane-3'',9''-diylidene)bis(2,2-dimethyl-1,3-dioxan-4,6-dione) (9).At both 650 deg C and 700 deg C compound (3) yields only benzyne while (8) yields ketenes and benzyne.It is suggested that compounds (1), (2) and (3) undergo concerted fragmentation to benzyne while (8) and (9) give ketene intermediates which fragment to benzyne.

Synthesis of Fused Polycyclic 1,4-Benzodiazepines via Metal-Free Cascade [5 + 2]/[2 + 2] Cycloadditions

A metal-catalyst-free, mild, and efficient synthetic protocol for polycyclic 1,4-benzodiazepines via cascade [5 + 2]/[2 + 2] cycloadditions between pyridinium zwitterions and arynes is reported. Mechanistic experiments revealed that pyridinium zwitterions act as 1,5-dipoles in [5 + 2] cycloadditions with arynes for the construction of 1,4-benzodiazepines, which further undergo [2 + 2] cycloaddition resulting in the one-pot formation of one C-N bond and three C-C bonds.

Reactions of an Isolable Dialkylstannylene with Propynoates and Benzyne

The reactions of stable monomeric dialkylstannylene 1 with methyl and ethyl propynoates give the corresponding 1:2 adducts, alkenyl(alkynyl)stannane 2 and 3 in high yields, while 1 does not react with parent acetylene or common mono- and disubstituted acetylenes such as phenylacetylene, trimethylsilylacetylene, diethyl 2-butynedioate, etc. Notably, 2 and 3 have the Z-configuration of the alkenyl moieties, in contrast to similar adducts obtained by the known reactions of silylenes with terminal acetylenes. It is suggested that the formation of a carbonyl oxygen-coordinate cyclic zwitterion as a key intermediate is essential for the reactions. Stannylene 1 adds to in situ generated benzyne, forming a 1:1 adduct having a unique 3-stanna-1-silaindane ring system.

Temporary intramolecular generation of pyridine carbenes in metal-free three-component C - H bond functionalisation/aryl-transfer reactions

Nucleophilic addition of pyridines to benzyne generates zwitterionic adducts that evolve by a rapid intramolecular proton shift to produce the corresponding pyridine carbenes, N-phenyl pyrid-2-ylidenes. In the presence of electrophilic ketones (isatin derivatives), the pyridylidenes can further react by an original bis-arylation reaction of the carbonyl compounds involving a formal pyridine C - H bond functionalisation. The overall transformation is an unprecedented three-component reaction featuring a carbene intermediate. The mechanism of this transformation was examined in detail by using both experimental and theoretical approaches. It was found that the generation of N-phenyl pyrid-2-ylidene from pyridine and benzyne is energetically favoured, and that the corresponding carbene dimer can also form easily. Under the three-component reaction conditions, the pyridylidene preferentially adds to the ketone group of the isatin derivative to produce a zwitterionic adduct amenable to an intramolecular aryl transfer reaction by a concerted nucleophilic aromatic substitution. This peculiar reactivity for a carbene was compared to possibly competitive known reactions of stable carbenes with carbonyl compounds, and the reaction was found to be under thermodynamic control. The reported method of generation of N-phenyl pyrid-2-ylidenes and their reactivity with carbonyl compounds unlock new perspectives in organic synthesis. Carbene reactivity: Pyridine reacts with benzyne by a nucleophilic addition/ intramolecular proton shift sequence to generate N-phenyl pyrid-2-ylidenes (see scheme). These unusual carbenes react with isatin derivatives in an original three-component bis-arylation reaction involving a formal pyridine C - H bond functionalisation. The mechanism of the reaction has been investigated experimentally and theoretically.

Arynes and Their Precursors from Arylboronic Acids via Catalytic C-H Silylation

A new, operationally simple approach is presented to access arynes and their fluoride-activated precursors based on Ru-catalyzed C-H silylation of arylboronates. Chromatographic purification may be deferred until after aryne capture, rendering the arylboronates de facto precursors. Access to various new arynes and their derivatives is demonstrated, including, for the first time, those based on a 2,3-carbazolyne and 2,3-fluorenyne core, which pave the way for novel derivatizations of motifs relevant to materials chemistry.

Microwave-induced covalent functionalization of few-layer graphene with arynes under solvent-free conditions

A non-conventional modification of exfoliated few-layer graphene (FLG) with different arynes under microwave (MW) irradiation and solvent-free conditions is reported. The described approach allows reaching fast, efficient and mild covalent functionalization of FLG.

ROOM TEMPERATURE POLYMER CROSSLINKING USING 1-FUNCTIONALIZED BENZOCYCLOBUTENE

Specific benzocyclobutenes serve as intramolecular or intermolecular or both intramolecular or intermolecular crosslinkers. The benzocyclobutenes can be incorporated into polymers post polymerization or can be provided as monomers that participate in homo

Lewis acid triggered reactivity of a lewis base stabilized scandium-terminal imido complex: C-H bond activation, cycloaddition, and dehydrofluorination

A stable scandium-terminal imido complex is activated by borane to form an unsaturated terminal imido complex by removing the coordinated Lewis base, 4-(dimethylamino)pyridine, from the metal center. The ensuing terminal imido intermediate can exist as a

Pitfalls in the photoelectron spectroscopic investigations of benzyne. photoelectron spectrum of cyclopentadienylideneketene

The 9.24 eV ionization energy often quoted in photoelectron spectroscopic investigations of benzyne is not due to benzyne 1 but to benzene, C 6H6. The 8.9 eV ionization is not due to benzyne either but to cyclopentadienylideneketene 12 when a 10.2 eV band is also present, or to biphenylene 5 when a 7.6 eV band is simultaneously present. Cyclopentadienylideneketene 12 has been generated by flash vacuum thermolysis of four different precursors, which permit a linking of infrared, mass, and photoelectron spectroscopic observations.

Mass spectrometry of benzyne and cyclopentadienylideneketene

The formation of cyclopentadienylideneketene 2 and benzyne 1 in flash vacuum thermolysis reactions is investigated by on-line mass spectrometry. Compounds 13, 14, and 15 all afford ketene 2, which decomposes to benzyne and CO in the high-temperature regime. Cyclopentadienylideneketene 2 is stable on the microsecond time-scale of neutralization-reionization experiments. Collisional activation mass spectrometry of m/z 76 from 14, 15, and 5 indicates that the C6H4·+ ions most likely undergo ring opening in the mass spectrometer.