Synthesis of SF₅-containing benzisoxazoles, quinolines, and quinazolines by the Davis reaction of nitro-(pentafluorosulfanyl)benzenes

Abstract

Summary Meta- or para-nitro-(pentafluorosulfonyl)benzenes underwent the Davis reaction with arylacetonitriles to provide the SF5-containing benzisoxazoles. Good yields were obtained with arylacetonitriles containing the electron-neutral or electron-donor group, while those with the electron-acceptor group were found to be unreactive. Reductions of the benzisoxazoles gave ortho-aminobenzophenones in high yields. Their synthetic utility was demonstrated by condensation reactions with carbonyl compounds or amines to provide SF5-containing quinolines and quinazolines, respectively.

Single crystal X-ray structural features of aromatic compounds having a pentafluorosulfuranyl (SF5) functional group

“…Compounds 1-3 were obtained from Apollo Scientific without further purification; compounds 4 [19], 5 [20], 6 [19], 7 [21], 8 [22], and 9 [21] were prepared according to the literature method. The crystal structure data were collected by using a Rigaku SCX-Mini diffractometer (Mercury 2 CCD) at -148℃with graphite-monochromated Mo-Kα radiation (λ= 0.71073 Å) for compounds 1-4, 6, 7 and 9; a Mercury diffractometer (Mercury 70) at -148℃ for compound 5, and the St Andrews Robotic diffractometer (Saturn70 CCD) at -148℃ [23][24][25] for compound 8.…”

Synthesis and Characterization of 2‐Pyridylsulfur Pentafluorides

“…The first group is larger and is composed of fused bicyclic heterocycles, where the SF 5 group is attached to the benzene part of a benzannulated heterocycle. These compounds have always been prepared from a SF 5 ‐substituted aryl precursor, exploiting well‐known cyclization techniques to build heterocyclic systems of indole,5a,b indazole,5c benzimidazole,5d–f benzoxazole,5g benzisoxazole,5h benzothiophene,5a benzothiazole,5i benzotriazole,5d quinoline,3d,e,h, 5h quinoxaline,5d and quinazoline 5h. The second smaller group comprises monocyclic aromatic SF 5 ‐substituted heterocycles: pyrroles,5j,k furans,5l,m thiophenes,5j,k pyrazoles,5n,o isoxazoles,5m and triazoles 5o–q.…”

Introduction of Carbon Substituents into Nitroarenes via Nucleophilic Substitution of Hydrogen: New Developments

“…2,1-Benzisoxazoles were also formed in the reaction of 1-nitro-4-and -3-(pentafluorosulfanyl)benzenes with a variety of arylacetonitriles (Scheme 29). 74…”