Organocatalytic Asymmetric C(sp2 )-H Allylic Alkylation: Enantioselective Synthesis of Tetrasubstituted Allenoates.

Herein we describe the first organocatalytic asymmetric C(sp2 )-H allylation of racemic trisubstituted allenoates with Morita-Baylis-Hillman (MBH) carbonates to access axially chiral tetrasubstituted allenoates. Various trisubstituted allenoates and MBH carbonates were well tolerated under mild reaction conditions, providing novel chiral tetrasubstituted allenoates with adjacent axial chirality and tertiary carbon stereocenters in high yields with good to excellent diastereoselectivities and enantioselectivities.