Solvent-free direct α-alkylation of ketones by alcohols catalyzed by nickel supported on silica-alumina

• Published in: Green chemistry : an international journal and green chemistry resource : GC 2018, Vol.2 (18), p.421-4216
• Main Authors: Charvieux, Aubin, Giorgi, Javier B, Duguet, Nicolas, Métay, Estelle
• Format: Article
• Language: English
• Subjects: Acetophenone; Alcohol; Alkylation; Aluminum oxide; Benzyl alcohol; Catalysis; Catalysts; Chemical Sciences; Green chemistry; Ketones; Nickel; Organic chemistry; Recovering; Recyclability; Silicon dioxide; Solvents
• ISSN: 1463-9262; 1463-9270
• DOI: 10.1039/c8gc01958d

The α-alkylation of acetophenone with benzyl alcohol through borrowing hydrogen has been studied using nickel catalysis. Ni/SiO 2 -Al 2 O 3 was found to be the best catalyst for this transformation and the corresponding alkylated acetophenone was obtained with 93% isolated yield. Following the objectives of clean and sustainable chemistry, the reaction occurs under solvent-free conditions and requires only a catalytic amount of base. This protocol was next applied to a wide range of ketones and alcohols and the desired products were isolated with 18-86% yields (26 examples). The recovery and recyclability of the nickel catalyst was also investigated and it was found to be active over 5 runs without significant loss of activity. Surprisingly, the active catalyst appears to include an amorphous nickel hydroxide layer. The α-alkylation of acetophenone with benzyl alcohol through borrowing hydrogen has been studied using nickel catalysis.