substrates 1 and 2 can be regioselectively converted into chiral allenyl alcohols 3 through the title reaction [Eq. (1)] with the synergetic reagent iPrSBEt2 and a chiral TiIV catalyst. The dramatic regioselectivity originates from the regulation of the equilibriumbetween propargyl- and allenylstannanes during the catalytic process.
Practical and efficient catalytic asymmetric allylic transfer reactions of achiral aldehydes with tin reagents promoted by BINOL-Ti(IV) complex are achieved with high enantioselectivity by the utilization of subjoined Lewis acid, B(OMe)3.