The first primary aminocatalytic direct cross-aldol reaction of acetaldehyde is presented. Among the various vicinal diamines screened, the L-tert-leucine derivative 1c in conjunction with (H4SiW12O40)0.25 was identified as the optimal catalyst; good catalytic activity (up to 99 % yield in 4 h), and high enantioselectivities (up to 92 % ee) were achieved for a range of donors, including aromatic aldehydes
The ability of counterion enhanced catalysis to promote the asymmetric functionalization of enones was demonstrated. Combining the use of sterically demanding phosphoric acids with simple chiral diamines allowed for the preparation of simple ion-paired and highly tunable organocatalysts. The latter could be applied in four different asymmetric transformations, providing a highly enantioselective access