ortho-halogeno substituents effect in asymmetric cyclization of 4-aryl-4-pentenals using a rhodium catalyst
Asymmetric cyclization of 4-aryl-4-pentenals by using a cationic [Rh((R)-BINAP)]ClO4 afforded (3R)-3-substituted cyclopentanones; on the other hand, the cyclization of 4-pentenals bearing ortho-halogeno phenyl groups afforded the opposite (3S)-ones.