Fig. 4.

Scope of the substrate and Grignard reagent. ^aFor details see Supplementary Information. Isolated yields for all the products are shown. The absolute configuration of the products obtained with (R)-L4 or (R,R)-L5 as the ligands are opposite. ^bReaction conditions: 0.1 M of the substrate in tBuOMe with 5 mol% (R)-L4/CuBr·SMe₂ or in tBuOMe/toluene = 1/1 with 10 mol% (R,R)-L5/CuBr·SMe₂, 2–3 equiv. of Me₃SiOTf and RMgBr. ^cUsing 5 mol% (R,R)-L5/CuBr·SMe₂ as a catalyst in the same condition led to 1a with 93% ee. ^dUsing 5 mol% (R)-L4/CuBr·SMe₂ as a catalyst led to 2e with 57% ee. ^eThe reaction performed using 10 mol% of (R)-L4/CuBr·SMe₂. ^fThe reaction performed at −40 °C