Synlett 2006(8): 1255-1259  
DOI: 10.1055/s-2006-939682
LETTER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of 4-Nitrophenyl Sulfones and Application in the Modified Julia Olefination

Daniela Mirk, Jean-Marie Grassot, Jieping Zhu*
Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-sur-Yvette Cedex, France
Fax: +33(1)69077247; e-Mail: zhu@icsn.cnrs-gif.fr;
Further Information

Publication History

Received 21 December 2005
Publication Date:
05 May 2006 (online)

Abstract

4-Nitrophenyl (NP) sulfones have been successfully employed in the modified Julia olefination reaction with carbonyl compounds. The olefination reaction proceeds through a sequence of aldol addition, Smiles rearrangement, and elimination. The sulfones are easily prepared in high yields in a two-step sequence starting from inexpensive commercially available para-fluoronitrobenzenes via nucleophilic aromatic substitution by a mercaptane and sub­sequent oxidation under standard conditions. The modified Julia ­reaction between NP sulfones and a wide variety of aromatic aldehydes affords the corresponding styrenes, stilbenes and cinnamate derivatives in yields up to 97% and good stereoselectivities. A mechanistic rationale is advanced to explain the observed results.

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Yields and E/Z ratios of the modified Julia olefination with NP sulfones using KHMDS as base after flash chromatography for 2ba: 14% (97:3), 2bb: 55% (>99:1), 2bd: 33% (96:4), 2bg: 58% (95:5), 2ca: 23% (88:12), 2cb: 48% (52:48), 2cd: 32% (94:6), 2cg: 73% (59:41).