Hydrovinylation of norbornene. Ligand-dependent selectivity and asymmetric variations.
[reaction: see text] Norbornene undergoes Ni-catalyzed (1-2 mol% allylnickel bromide/phosphine/NaBARF or AgSbF(6), 1 bar ethylene, -50 degrees C) hydrovinylation (>97% yield), giving either a 1:1 or a 2:1 (norbornene/ethylene) adduct depending on the size of the phosphine. Use of binaphthol-derived phosphoramidite ligand results in up to 80% ee for the 1:1 adduct. The course of the reaction is highly dependent on the ligand (size and configuration of the appendages) and the counteranion present.
Department of Chemistry, 100 W. 18th Avenue, The Ohio State University, Columbus, Ohio 43210, USA.
Ramaiah
R
Kumareswaran
Malay
M
Nandi
T V
TV
RajanBabu