Conjugate Additions of <i>o</i>-Iodoanilines and Methyl Anthranilates to Acetylenic Sulfones. A New Route to Quinolones Including First Syntheses of Two Alkaloids from the Medicinal Herb <i>Ruta chalepensis</i>
作者:Thomas G. Back、Masood Parvez、Jeremy E. Wulff
DOI:10.1021/jo026595t
日期:2003.3.1
especially when the aniline contained an electron-withdrawing substituent such as an ester group. In some cases, the reactions were enhanced by the presence of DMAP and the use of an excess of the sulfone in aqueousDMF. N-Formylanilines proved superior to free anilines. The products were either vinyl or allyl sulfones, depending on the conditions and the structure of the reactants. The acetylenic sulfone
Indole Synthesis by Conjugate Addition of Anilines to Activated Acetylenes and an Unusual Ligand-Free Copper(II)-Mediated Intramolecular Cross-Coupling
作者:Detian Gao、Thomas G. Back
DOI:10.1002/chem.201202307
日期:2012.11.12
A versatile new synthesis of indoles was achieved by the conjugate addition of N‐formyl‐2‐haloanilines to acetylenic sulfones, ketones, and esters followed by a copper‐catalyzed intramolecular C‐arylation. The conjugate addition step was conducted under exceptionally mild conditions at room temperature in basic, aqueous DMF. Surprisingly, the C‐arylation was performed most effectively by employing
Direct and Efficient Synthesis of Sulfonium Acyl Sulfonylmethylide Ylides from Acetylenic Sulfones and Dimethyl Sulfoxide
作者:Jiaxi Xu、Duo Fu、Jiayi Wang
DOI:10.1055/a-1541-6271
日期:2021.11
sulfonium ylides – sulfonium acyl sulfonylmethylides – were directly and efficiently prepared from various acetylenic sulfones and aliphatic sulfoxides under heating conditions. The current method features short reaction time, low cost, readily available starting materials, convenient operation, and purification, providing an efficient access to widely applied bifunctionalized sulfonium ylides.
Use of an acetylenic sulfone as an alkene dipole equivalent in the synthesis of (±)-pumiliotoxin C
作者:Thomas G. Back、Katsumasa Nakajima
DOI:10.1016/s0040-4039(96)02506-3
日期:1997.2
yclohexanecarboxylate (3) with 1-p-(toluenesulfonyl)-1-pentyne (4) afforded the corresponding enaminone 2, that was in turn reduced to (±)-pumiliotoxin C (1). The acetylenic sulfone 4 thus functions as the synthetic equivalent of the alkene dipole 5 in this process.
Synthesis of Substituted Piperidines, Indolizidines, Quinolizidines, and Pyrrolizidines via a Cycloaddition Strategy Using Acetylenic Sulfones as Alkene Dipole Equivalents
作者:Thomas G. Back、Katsumasa Nakajima
DOI:10.1021/ol990592u
日期:1999.7.1
The conjugate additions of beta- and gamma-chloroamines to acetylenic sulfones afford enamine sulfones, which then undergo intramolecular alkylation to produce the corresponding cyclic enamines, This provides a convenient route to substituted piperidines, indolizidines, quinolizidines, and pyrrolizidines. The enantioselective total synthesis of the alkaloid (-)-indolizidine 167B (also named gephyrotoxin 167B) was thus achieved by the cycloaddition of (S)-2-(2-chloroethyl)pyrrolidine to 1-(p-toluenesulfonyl)-1-pentyne, followed by stereoselective reduction of the enamine moiety and reductive desulfonylation.