Synthesis of axially chiral C10-BridgePHOS oxides and their use as organocatalysts in enantioselective allylations of aldehydes

A series of C10-BridgePHOS oxides possessing different substituted groups on the diphenyl phosphine system were synthesized and tested as organocatalysts in the allylation of aldehydes with allyltrichlorosilane, providing chiral homoallylic alcohols. These types of organocatalysts showed high catalytic activity and only 2 mol% catalyst loading was required to induce short reaction times. Under optimal reaction conditions, excellent product yields and up to 92% ee were obtained for a variety of substrates.