Photochemistry of fluorophenyl azides in aniline

Photochemically Induced Aryl Azide Rearrangement: Solution NMR Spectroscopic Identification of the Rearrangement Product

“…In the next step, ketenimine 4 is likely converted to anti-Bredt imine 5 by photochemical four-electron electrocyclization, which further rearranges to 6 under irradiation conditions . In agreement with previous studies of mono- ortho -fluoro-substituted phenylnitrenes, ,,− at high temperature, cyclization toward the fluorine-substituted ortho -carbon C2 of 2 , giving benzazirine 3 , is favored over cyclization toward the unsubstituted ortho -carbon C7 which leads to benzazirine 7 . At lower temperatures, the opposite selectivity is expected.…”

Through‐space 19F–19F spin–spin coupling in ortho‐fluoro Z‐azobenzene

“…Belger et al reported the synthesis and photoisomerization of p,p′ ‐disubstituted tetrafluoroazobenzene; we adopted their synthesis for compound 10 . Compounds 9 and 10 have been previously reported . As prepared, the configuration of these compounds is principally the more stable E isomer, which can be converted to a mixture of Z and E within minutes using UV irradiation.…”

“…Compounds 9 and 10 have been previously reported. [11] As prepared, the configuration of these compounds is principally the more stable E isomer, which can be converted to a mixture of Z and E within minutes using UV irradiation. The thermal Z to E isomerization is sufficiently slow so that isomer separation is possible by flash chromatography (R f -Z > R f -E for hydrocarbon mobile phase and silica absorbant).…”

Chemoselective Deprotonative Lithiation of Azobenzenes: Reactions and Mechanisms

“…-Deprotonative Lithiation of Azobenzenes 14−20 with LTMP: Reactions and Structural Elucidation (Table 1-(4-Methoxyphenyl)-2-phenyldiazene ( 14) is commercially available from a chemical supplier. 1-(4-Fluorophenyl)-2-phenyldiazene (15), 29 1-(3fluorophenyl)-2-phenyldiazene (18), 30 1-(2-fluorophenyl)-2-phenyldiazene (20), 31 and 1-(3-methoxyphenyl)-2-phenyldiazene (17) 32 were synthesized by condensation of nitrosobenzene with, respectively, 4-fluoroaniline, 3-fluoroaniline, 2-fluoroaniline, and 3-methoxyaniline. N,N-Diethyl-4-(phenyldiazenyl)benzamide (16) and the meta isomer 19 were synthesized from the corresponding phenyldiazenylbenzoyl chlorides and diethylamine in dry dichloromethane under nitrogen.…”