Synthesis and Resolution of Substituted [5]Carbohelicenes
摘要:
Three types of racemic [5]helicenyl acetates (la, 2, and 3a) were synthesized. The synthesis of 2 was achieved by regioselective oxidation using o-iodoxybenzoic acid. The enzymatic kinetic resolution of la-3a was studied. The conversion with the highest rate and ee was obtained using la as the substrate and lipase Amano PS-IM as the enzyme. The two enantiomers of 1-[5]helicenol 3b were separated using (1S)-10-camphorsulfonyl chloride as the chiral resolving agent.
Three types of racemic [5]helicenyl acetates (la, 2, and 3a) were synthesized. The synthesis of 2 was achieved by regioselective oxidation using o-iodoxybenzoic acid. The enzymatic kinetic resolution of la-3a was studied. The conversion with the highest rate and ee was obtained using la as the substrate and lipase Amano PS-IM as the enzyme. The two enantiomers of 1-[5]helicenol 3b were separated using (1S)-10-camphorsulfonyl chloride as the chiral resolving agent.
Internal-Edge-Substituted Coumarin-Fused [6]Helicenes: Asymmetric Synthesis, Structural Features, and Control of Self-Assembly
diverse chemical and electronic structures, as well as tunable physicalproperties. It was rationally anticipated that the self‐assembly of coumarin‐fused helicenes would be controlled by the effects of a substituent on the internal edge of the helix. Here, this work reports the efficient syntheses of coumarin‐fused helicenes 1 a,b (R=Ph, Me), and the enantioselective synthesis of 1 a (R=Ph) by chiral AuI‐catalyzed