83179-46-8

Upstream product

• 857488-49-4 N-(3-methyl-[2]naphthyl)-benzamide 
• 59046-65-0 (E)-1-(phenylethynyl)-2-(prop-1-en-1-yl)benzene 
• 100008-35-3 2-(isochroman-1-yl)-1-phenylpropan-1-one 
• 673-32-5 1-Phenylprop-1-yne 
• 59046-72-9 o-(phenylethynyl)benzaldehyde 
• 31675-35-1 (2-Formyl-benzyl)-triphenyl-phosphonium; bromide 
• 591-50-4 iodobenzene 
• 1362738-84-8 C₂₉H₂₅BF₁₀Si₂ 
• 1362738-79-1 C₂₀H₂₂Si 
• 60815-16-9 2-(o-formylphenyl)-1-phenylethanone 
• 7647-01-0 hydrogenchloride 
• 6630-33-7 ortho-bromobenzaldehyde 
• 176910-67-1 2-(4-methoxyphenylethynyl)benzaldehyde 
• 38846-64-9 2-ethynylbenzaldehyde 

Relevant academic research and scientific papers

Metal-free benzannulation to synthesis of 2,3-disubstituted naphthalenes: Reaction of 2-(Phenylethynyl)benzaldehyde and alkynes by Br?nsted acid

Metal-free benzannulation reaction of 2-(phenylethynyl)- benzaldehyde and alkynes proceeded in the presence of Br?nsted acid under microwave irradiation to give the 2,3- disubstituted naphthalenes.

Alkenes as alkyne equivalents in radical cascades terminated by fragmentations: Overcoming stereoelectronic restrictions on ring expansions for the preparation of expanded polyaromatics

Chemoselective interaction of aromatic enynes with Bu3Sn radicals can be harnessed for selective cascade transformations, yielding either Sn-substituted naphthalenes or Sn-indenes. Depending on the substitution at the alkene terminus, the initial regioselective 5-exo-trig cyclizations can be intercepted at the 5-exo stage via either hydrogen atom abstraction or C-S bond scission or allowed to proceed further to the formal 6-endo products via homoallylic ring expansion. Aromatization of the latter occurs via β-C-C bond scission, which is facilitated by 2c,3e through-bond interactions, a new stereoelectronic effect in radical chemistry. The combination of formal 6-endo-trig cyclization with stereoelectronically optimized fragmentation allows the use of alkenes as synthetic equivalents of alkynes and opens a convenient route to α-Sn-substituted naphthalenes, a unique launching platform for the preparation of extended polyaromatics.

Rerouting radical cascades: Intercepting the homoallyl ring expansion in enyne cyclizations via C-S scission

The switch from 5-exo- to 6-endo-trig selectivity in the radical cyclization of aromatic enynes was probed via the combination of experimental and computational methods. This transformation occurs by kinetic self-sorting of the mixture of four equilibrating radicals via 5-exo-trig cyclization, followed by homoallyl (3-exo-trig/fragmentation) ring expansion to afford the benzylic radical necessary for the final aromatizing C-C bond fragmentation. The interception of the intermediate 5-exo-trig product via β-scission of a properly positioned weak C-S bond provides direct mechanistic evidence for the 5-exo cyclization/ring expansion sequence. The overall cascade uses alkenes as synthetic equivalents of alkynes for the convenient and mild synthesis of Bu3Sn-functionalized naphthalenes.

Iron-catalyzed benzannulation reactions of 2-alkylbenzaldehydes and alkynes leading to naphthalene derivatives

An efficient and practical method for the synthesis of naphthalene derivatives via Fe(III)-catalyzed benzannulation of 2-(2-oxoethyl)-benzaldehydes and alkynes has been developed. The system holds the advantages of cheap catalysts, wide substrate scope, and mild reaction conditions.

1,1-carboboration route to substituted naphthalenes

1,2-Bis(alkynyl)benzene derivatives react with strongly electrophilic boranes to yield in boryl-functionalized bulky naphthalene derivatives by means of a sequence of 1,1-carboboration reactions. These substrates can be functionalized by transition metal

ZnCl2-catalyzed [4 + 2] benzannulation of 2-ethynylbenzaldehydes with alkynes: Selective synthesis of naphthalene derivatives

Zn-catalyzed [4 + 2] benzannulation of 2-ethynylbenzaldehydes with alkynes is described for the selective synthesis of naphthalene derivatives. In the presence of ZnCl2, a variety of 2-ethynylbenzaldehydes underwent the [4 + 2] benzannulation reactions with alkynes to selectively afford the corresponding naphthalene derivatives in moderate to good yields.

Annulations Using Phosphonium Salts and Enolate Anions - A Direct Route to Naphthalenes

Ketone enolates react with an aldehyde phosphonium salt to produce naphthalenes in a one-pot reaction.

Lewis acid-catalyzed benzannulation via unprecedented [4+2] cycloaddition of o-alkynyl(oxo)benzenes and enynals with alkynes

The reaction of o-alkynyl(oxo)benzenes 1 with alkynes 2 in the presence of a catalytic amount of AuCl3 in (CH2Cl)2 at 80 °C gave the [4+2] benzannulation products, naphthyl ketone derivatives 3 and 4, in high yields. When the reaction was carried out using AuBr3 instead of AuCl3, the reaction speed was enhanced and the chemical yield was increased. On the other hand, when the reaction was carried out in the presence of a catalytic amount of Cu(OTf)2 and 1 equiv of a Bronsted acid, such as CF2HCO2H, in (CH 2Cl)2 at 100 °C, the decarbonylated naphthalene products 5 were obtained in high yields. Similarly, the Cu(OTf) 2-H2O-promoted reaction of the enynals 7 with an alkyne 2 afforded the corresponding [4+2] benzannulation products, decarbonylated benzene derivatives 8, in good yields. Both AuX3- and Cu(OTf) 2-catalyzed benzannulations proceed most probably through the formation of the benzo[c]pyrylium ate complex 10, the Diels-Alder addition of alkynes 2 to the ate complex, and the resulting bicyclic pyrylium ion intermediate 12. The mechanistic difference between the AuX3 and Cu(OTf)2-HA system is discussed.

TRANSFORMATION OF (ISOCHROMAN-1-YL)METHYLENEKETONES TO NAPHTHALENE DERIVATIVES

Treatment of (isochroman-1-yl)methylketones (2c-h) with potassium tert-butoxide gave different naphthalene derivatives (5-14) via novel ring transformation, depending on the presence or absence and the nature of the substituents adjacent to the carbonyl group in 2.

The Photochemistry of 2-Vinyldiphenylacetylene and Related Compounds

Irradiation of solutions of 2-vinyldiphenylacetylene (5) under anaerobic conditions gives 2-phenylnaphtalene (9) in 90 percent yield.Several derivatives of (5) behave similarly.The reaction is ascribed to the primary formation of a cyclic allene (29), as has been proposed previously for the analogous photocyclization of 1,4-diarylbutenynes into phenylaromatic compounds.The end-product arises from (29) either via a 1,5-hydrogen shift or by addition and elimination of a proton.Irradiation of 2-ethynylstilbene (21) also yields (9), but 1-ethynylphenanthrene (22) is formed as a side-product.