Enantioselective synthesis of homoallylic alcohols by nucleophilic addition of chirally modified allylboron reagents to aldehydes was investigated. Reaction of enantiopure N-sulfonylamino alcohols (la, Ib, 3a, 4a) with triallylborane gave the chiral allylboration reagents. Aldehydes were converted to enantioenriched homoallylic alcohols with the reagents. Polymer-supported chiral allylboron reagents were also prepared from triallylborane and crosslinked polymers having chiral N-sulfonylamino alcohol moieties (5-8). These polymeric reagents reacted with aldehydes to give optically active homoallylic alcohols in high chemical yield with high enantioselectivities. Optical yield up to 92% ee was obtained by the use of polymeric chiral ligand 7 derived from D-camphor. The potential of this type of approach in asymmetric synthesis is discussed.