Details

Autor(en) / Beteiligte

• Coyle, Emma E.
• Doonan, Bryan J.
• Holohan, Andrew J.
• Walsh, Killian A.
• Lavigne, Florie
• Krenske, Elizabeth H.
• O'Brien, Christopher J.

Titel

Catalytic Wittig Reactions of Semi- and Nonstabilized Ylides Enabled by Ylide Tuning

Ist Teil von

• Angewandte Chemie International Edition, 2014-11, Vol.53 (47), p.12907-12911

Auflage

International ed. in English

Ort / Verlag

Weinheim: WILEY-VCH Verlag

Erscheinungsjahr

2014

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• The first examples of catalytic Wittig reactions with semistabilized and nonstabilized ylides are reported. These reactions were enabled by utilization of a masked base, sodium tert‐butyl carbonate, and/or ylide tuning. The acidity of the ylide‐forming proton was tuned by varying the electron density at the phosphorus center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement of E selectivity up to >95:5, E/Z. Time for a tune up: Catalytic Wittig reactions with semi‐ and nonstabilized ylides were enabled by use of a masked base (NaOCO2tBu) and/or ylide tuning. The acidity of the ylide‐forming proton was tuned by varying the electron density at the P center in the precatalyst, thus facilitating the use of relatively mild bases. Steric modification of the precatalyst structure resulted in significant enhancement of E selectivity.