Hidden Brønsted acid catalysis: pathways of accidental or deliberate generation of triflic acid from metal triflates.
The generation of a hidden Brønsted acid as a true catalytic species in hydroalkoxylation reactions from metal precatalysts has been clarified in case studies. The mechanism of triflic acid (CF(3)SO(3)H or HOTf) generation starting either from AgOTf in 1,2-dichloroethane (DCE) or from a Cp*RuCl(2)/AgOTf/phosphane combination in toluene has been elucidated. The deliberate and controlled generation of HOTf from AgOTf and cocatalytic amounts of tert-butyl chloride in the cold or from AgOTf in DCE at elevated temperatures results in a hidden Brønsted acid catalyst useful for mechanistic control experiments or for synthetic applications.
Department Chemie, Technische Universität München, 85748 Garching b. München, Germany.
Tuan Thanh
TT
Dang
Florian
F
Boeck
Lukas
L
Hintermann