Rhodium-Catalyzed, Enantioselective Hydroacylation of ortho-Allylbenzaldehydes.

The development of a rhodium catalyst for endo- and enantioselective hydroacylation of ortho-allylbenzaldehydes is reported. A catalyst generated in situ from [Rh(COD)Cl]2, (R)-DTBM-SEGPHOS, and NaBARF promotes the desired hydroacylation reactions and minimizes the formation of byproducts from competitive alkene isomerization and ene/dehydration pathways. These rhodium-catalyzed processes generate the 3,4-dihydronaphthalen-1(2H)-one products in moderate-to-high yields (49-91%) with excellent enantioselectivities (96-99% ee).