Simple, convenient, and direct conversion of anilines and anilides into arynes

Abstract

EH9 3JJReaction of aniline with pentyl nitrite and acetic anhydride in benzene, or other solvents, gives benzyne in up to 32% yield as measured by trapping with anthracene, and tetraphenylcyclopentadienone and its 2.5-di-p-tolyl analogue. The role of the anhydride is to by-pass the suppressive effect of water on benzyne formation from the diazonium acetate ion pair. Reaction in benzene of aniline-acetic anhydride or (better) acetanilide with p-chlorobenzoyl nitrite (PCBN) (from silver p-chlorobenzoate and nitrosyl chloride) gives benzyne in up to 71% yield as measured by trapping as before and by 9.1 O-dimethoxyanthracene, and by the ene reaction with methyl methacrylate to give ethyl 2-methylene-3-phenylpropionate (31 %). m e w Substituted anilines and acetanilides (m-XCGHQ*-NHAc; X = F. CI, Br, I, CO,Et, MeO, But, CFs, or NO2) and 3-aminopyridine behave like aniline and acetanilide. the para-isomers give lower yields, and the ortho-isomers give little or no arynes. with the exception of ethyl anthranilate and 2.5-dimethoxy-and 2.5-dichloroaniline.

Diels–Alder Cycloaddition with CO, CO2, SO2, or N2 Extrusion: A Powerful Tool for Material Chemistry

“…Subsequently, report from Baigrie and co-workers claimed that substituted anilines and anilides were smoothly converted into substituted benzynes, followed by the application of the benzynes as dienophiles in DA cycloaddition to tetraphenylcyclopentadienone (or in some cases 2,-diphenyl3,4- p -tolylcyclopentadienone) with CO extrusion ( Scheme 227 ) [ 287 ].…”

“… Synthesis of tetraphenylnaphthalene derivatives via cycloaddition of substituted benzynes to tetraphenylcyclopentadienone [ 287 ]. Reagents and conditions: X = H or COOMe; Y = H, F, Cl, Br, I, Me, t -Bu, and other substituents in various position.…”

Solvent free, phosphine free Pd-catalyzed annulations of aryl bromides with diarylacetylenes

“…5-(Trifluoromethyl)-1,2,3,4-tetraphenylnaphthalene (3l) 15 . mp 178-180 uC; 1 H NMR (500 MHz, CDCl 3 ): d: 8.01 (d, J = 7.0 Hz, 1H), 7.89 (d, J = 8.5 Hz, 1H), 7.44 (t, J = 8.0 Hz, 1H), 7.30-7.08 (m, 10H), 6.90-6.73 (m, 10H); 13 C NMR (125 MHz, CDCl 3 ): d: 142.…”

“…It has been observed that the ortho and para substituted aryl bromides reacted with diphenylacetylene to provide only one product. In case of meta substituted aryl bromides (Table 2,entries 3,4,6,9,15,17,and Table 3, entry 2) a small amount of the isomeric product (5-10%) was also formed. Again, the heteroaryl bromides or iodide (Table 3, entries 6, 7 and 9) furnished only one regioisomer.…”

Rhodium‐ and Iridium‐Catalyzed Oxidative Coupling of Benzoic Acids with Alkynes via Regioselective C—H Bond Cleavage.

“…5,7-Dimethyl-1,2,3,4-Tetraphenylnaphthalene (4i) (entry 4 in Table 4): mp 251-257 o C (lit. 25 mp 249 o C); 1 H NMR (270 MHz, CDCl 3 ): d 1.92 (s, 3H), 2.30 (s, 3H), 6.71-6.84 (m, 10H), 7.05-7.22 (m, 11H), 7.28 (s, 1H); 13 C NMR (67.8 MHz, CDCl 3 ): d 21.6, 25.3, 124.8, 125.0, 125.1, 126.0, 126.1 (overlapped), 126.3, 126.7, 127.3, 129.1, 131.0, 131.2, 131.3, 131.5, 132.5, 133.5, 134.8, 135.5, 137.8, 138.3, 138.4, 139.4, 140.3, 140.7 (overlapped), 142.9; MS m/z 460 (M + ).5-Chloro-1,2,3,4-Tetraphenylnaphthalene (4j)24 (entry 5 in Table4) (as a mixture with 4c (4j:4c = 3:1)): 1 H NMR (270 MHz, CDCl 3 ): d 6.72-6.89 (m, 10H), 6.72-6.89 (m, 10H, 4c), 7.05-7.27 (m, 11H), 7.05-7.27 (m, 10H, 4c), 7.31 (dd, J = 9.1, 2.1 Hz, 1H, 4c), 7.51 (dd, J = 7.4, 1.3 Hz, 1H), 7.57 (d, J = 8.9 Hz, 1H, 4c), 7.58 (dd, J = 8.4, 1.3 Hz, 1H), 7.61 (d, J = 2.1 Hz, 1H, 4c);13 C NMR (67.8 MHz, CDCl 3 ): d 125.1, 125.3, 125.4, 125.6, 126.0, 126.2, 126.45, 126.51, 126.6, 127.0, 127.48, 127.52, 127.6, 127.8, 128.4, 128.7, 129.7, 129.8, 130.3, 130.8, 131.05, 131.09, 131.4, 131.85, 131.88, 134.5, 136.9, 138.7, 138.9, 139.0, 139.1, 139.5, 140.0, 141.1, 141.7; MS m/z 466, 468 (M + ).…”