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Generation of Phosphoranes Derived from Phosphites. A New Class of Phosphorus Ylides Leading to High E Selectivity with Semi-stabilizing Groups in Wittig Olefinations

Varinder K. Aggarwal,* J. Robin Fulton, Chris G. Sheldon and Javier de Vicente

*School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS, UK, Email: v.aggarwalbristol.ac.uk

V. K. Aggarwal, J. R. Fulton, C. G. Sheldon, J. de Vicente, J. Am. Chem. Soc., 2003, 125, 6034-6035.

DOI: 10.1021/ja029573x (free Supporting Information)


Abstract

Aryl tosylhydrazones react with t-BuOK, ClFeTPP, (MeO)3P, and aldehydes to furnish olefins with high E selectivity through a Wittig-type pathway via the corresponding diazo compounds, metal carbenes and phosphorous ylides. A Horner-Wadsworth-Emmons-type reaction of ethyl diazoacetate with aldehydes occurs with high E selectivity in the presence of LiBr via the phosphonate anion, formed through an Arbuzov reaction under completely base-free conditions.

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proposed reaction pathway


proposed reaction pathway



Key Words

Wittig Reaction, Horner-Wadsworth-Emmons Reaction, Arbuzov Reaction, Hydrazones, α-Diazo Esters, Olefination


ID: J48-Y2003-1480