Direct Coupling of Arylacetonitriles and Primary Alcohols to α‐Alkylated Arylacetamides with Complete Atom Economy Catalyzed by a Rhodium Complex–Triphenylphosphine– Potassium Hydroxide System
A direct synthesis of α‐alkylated arylacetamides from arylacetonitriles and primary alcohols has been accomplished for the first time. In the presence of the rhodium complex [Rh(cod)Cl]2/triphenylphosphine/potassium hydroxide system, the desired α‐alkylated arylacetamides were obtained in 74–92% yield under microwave conditions. The experimental results in this paper are in sharp contrast with previous reports, where the coupling of arylacetonitriles and primary alcohols produced the α‐alkylated arylacetonitriles. Mechanistic investigations show that arylacetonitriles are first α‐alkylated with primary alcohols to produce α‐alkylated arylacetonitriles, which are further hydrated with the water resulting from the α‐alkylation step to produce α‐alkylated arylacetamides. More importantly, this research shows the potential of developing completely atom‐economical reactions that involve the hydrogen autotransfer (or hydrogen borrowing) process.
