Generation of phosphoranes derived from phosphites. A new class of phosphorus ylides leading to high E selectivity with semi-stabilizing groups in Wittig olefinations

Aggarwal, Varinder K, Fulton, J Robin, Sheldon, Chris G and de Vincente, Javier (2003) Generation of phosphoranes derived from phosphites. A new class of phosphorus ylides leading to high E selectivity with semi-stabilizing groups in Wittig olefinations. Journal of the American Chemical Society, 125 (20). pp. 6034-6035. ISSN 0002-7863

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Abstract

Tosylhydrazones derived from aryl aldehydes react with t-BuOK, ClFeTPP, (MeO)3P, and aldehydes to furnish olefins with high E selectivity. These reactions occur through a Wittig-type pathway via the corresponding diazo compounds, metal carbenes and phosphorous ylides, with the water-soluble trimethyl phosphate as the byproduct. Similar reactions can also be performed using ethyl diazoacetate; however, high E selectivity was only observed in the presence of LiBr. In this case, the reaction is believed to occur via the phosphonate anion, formed through an Arbuzov reaction. Thus this olefination reaction occurs through a Horner−Wadsworth−Emmons (HWE) reaction but the phosphonate anion is generated under completely base-free conditions.

Item Type: Article
Additional Information: First example using phosphite ylides in Wittig olefination reactions. Unexpectedly high E selectivity was observed, JRF carried out additional studies to understand these results. JRF contributed both to the results and writing of the manuscript in collaboration C. G. Sheldon. Cited over 40 times.
Schools and Departments: School of Life Sciences > Chemistry
Depositing User: Robin Fulton
Date Deposited: 06 Feb 2012 21:17
Last Modified: 30 Mar 2012 08:31
URI: http://sro.sussex.ac.uk/id/eprint/30623
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