Substrate scope^a,b,c,d.

^aReaction conditions: allylboronate (±)-3 (0.3 mmol, 3.0 equiv.), aldehyde (0.1 mmol, 1.0 equiv.), (S)-A (5 mol%), 4 Å molecular sieves, toluene, −45 °C; then NaOH, H₂O₂, 0 °C.

^b Z/E-selectivities were determined by ¹H NMR analysis of the crude reaction products.

^cYields of isolated products 4 are listed.

^dEnantiopurities of 4 were determined by HPLC analysis.

^eThe reactions were conducted with 10 mol% of (S)-A.