Brook/Elimination/Aldol Reaction Sequence for the Direct One-Pot Preparation of Difluorinated Aldols from (Trifluoromethyl)trimethylsilane and Acylsilanes

• Published in: Advanced synthesis & catalysis Vol. 358; no. 4; pp. 526 - 531
• Main Authors: Decostanzi, Mélanie, Godemert, Jérémy, Oudeyer, Sylvain, Levacher, Vincent, Campagne, Jean-Marc, Leclerc, Eric
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 18-02-2016; WILEY‐VCH Verlag; Wiley-VCH Verlag
• Subjects: Aldehydes; aldol reaction; Anions; Asymmetry; Brook rearrangement; Catalysis; Chemical reactions; Chemical Sciences; Fluorides; fluorine; organocatalysis; Reagents; Synthesis
• ISSN: 1615-4150; 1615-4169
• DOI: 10.1002/adsc.201500849

A methodology allowing the one‐pot preparation of difluorinated aldols directly from Ruppert–Prakash reagent, acyltrimethylsilanes and aldehydes is reported. The process, initiated by a catalytic amount of an ammonium salt, involves the addition of (trifluoromethyl)trimethylsilane to the acylsilane, followed by a Brook rearrangement and elimination of a fluoride anion that promotes the subsequent aldol reaction. An efficient racemic reaction catalyzed by tetrabutylammonium difluorotriphenylsilicate is described, as well as our first efforts towards an asymmetric version.