Enantioselective synthesis induced by tetrathia-[7]-helicenes in conjunction with asymmetric autocatalysis

Highly enantioenriched 5-pyrimidyl alkanol was formed using tetrathia-[7]-helicenes as a chiral initiator in the enantioselective addition of diisopropylzinc to pyrimidine-5-carbaldehyde, in conjunction with asymmetric autocatalysis.

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(P)-(+)-7,8-Dipropyldithieno[3,2-e:3′,2′-e′]benzo[1,2-b:4,3-b′]bis[1]benzothiopheneC28H22S4Ee = 98.9%[α]D20=+685 (c 0.187, CHCl3)Source of chirality: resolution using HPLC with a chiral stationary phase (Chiralpak IA)Absolute configuration: P