Cyclization of N-Aryl-N-tert-butoxycarbonyl-o-toluenesulfonamides to 2,3-Dihydro-1,2- benzisothiazole 1,1-Dioxides Accompanied by a Rearrangement of a tert-Butoxycarbonyl Group
摘要:
Treatment of N-aryl-N-tert-butoxycarbonyl-omicron-toluenesulfonamides with tert-butyllithium in the presence of TMEDA followed by addition of N,N-dimethylsulfamoyl chloride gave 2-aryl-3-tert-butoxycarbonyl-2,3-dihydro-1,2-benzisothiazole 1,1-dioxides in moderate yields accompanied by a rearrangement of a tert-butoxycarbonyl group.
The copper‐mediated fluroalkylation/cyclization of N‐allyl anilines has been described with unactivated double bonds as the radical acceptor. The reaction provides an efficient and direct access to 3‐fluoroalkyl indolines in moderate to good yields. This protocol combines a simple experimental procedure with low‐costing fluoroalkylated sources and excellent functional group tolerance.
Copper-Salt-Promoted Carbocyclization Reactions of α-Bromo-N-arylacylamides
作者:Che-Ping Chuang、Ying-Yu Chen、Tsung-Han Chuang、Cheng-Hao Yang
DOI:10.1055/s-0036-1588642
日期:——
Abstract A mild and convenient synthetic method for oxindoles and α-arylacylamides bearing an all carbon quaternary stereocenter from the readily available α-bromo-N-arylacylamides has been developed. This Cu(acac)2/Phen-promoted radical cyclization reaction, via the intramolecular radical cyclization onto the aryl moiety, can proceed in two different routes depending on the substituents on the nitrogen
Infrared Spectra of Phenylsulfonyl Derivatives. (4). The Infrared Spectra of N-Acylsulfonamide Derivatives. (Organic Analysis. XLVIII)
作者:Yo Ueda、Hiroshige Yano、Tsutomu Momose
DOI:10.1248/cpb.12.5
日期:——
The splitting phenomenon of the carbonyl absorptions and the shifts of S-N stretching vibrations to a longer wave length region of some N-acyl-N-substituted-sulfonamide derivatives measured in solid state were described. Tertiary sulfonamides had their SO2 stretching vibrations at a shorter wave length region than secondary sulfonamides. N-Acetyl-N-alkylmethane (or ethane) sulfonamide showed strong C-N stretching vibrations of the group N-CH2-R at about 1125cm-1. N-Acyl-N-substituted-sulfonamide derivatives had very strong asymmetric stretching vibrations of the group C-CO-N at 1250∼1290cm-1. Synthesis of some sulfonamide derivatives is also described.
Characteristic Hydrogen Bonding Observed in the Crystals of Aromatic Sulfonamides: 1D Chain Assembly of Molecules and Chiral Discrimination on Crystallization
achiral, except for kryptoracemates. In contrast, a high proportion of compounds with Helical or Straight patterns in the crystals showed chiral crystallization. Our classification is useful for discussion regarding the chirality of molecular assemblies, on the basis of the conformationalchirality of the molecules in the crystal.