Synthesis and Application of Substituted 1,16-Dihydroxytetraphenylenes in Catalytic Asymmetric Allylboration of Ketones.

The synthesis and application of a newly designed C2-symmetric chiral-substituted 1,16-dihedroxytetraphenylene (DHTP) is reported. Efficient syntheses of enantiopure substituted DHTP were accomplished, and these enantiopure compounds were used as organocatalysts in asymmetric allylboration of ketones under very mild conditions. Accordingly, several tertiary alcohols were generated in moderate to good yields with up to 99% ee by using the catalyst ( S)-2,15-Br2-DHTP. A gram-scale reaction was achieved in 99% yield with 96% ee.