Enantioselective addition of alkenylzinc reagents to aldehydes with organoboronates as the alkenyl source

Alkenylboronates were used as a vinyl source in the asymmetric addition of an alkenylzinc reagent to aldehydes catalyzed by a dendritic ligand. The resulting allylic alcohol products were obtained in 66–96% ee and 35–64% yields.

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(1S)-(E)-1,3-Diphenylprop-2-en-1-olC15H14OEe = 96%[α]D24=-31.5 (c 0.75, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)

(1S)-(E)-3-Phenyl-1-p-tolylprop-2-en-1-olC16H16OEe = 92%[α]D22=-22.3 (c 0.50, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S)

(1S)-(E)-1-(4-Chlorophenyl)-3-phenylprop-2-en-1-olC15H13ClOEe = 93%[α]D22=-16.8 (c 0.65, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S)

(1S)-(E)-1-(4-Bromophenyl)-3-phenylprop-2-en-1-olC15H13BrOEe = 84%[α]D25=-14.9 (c 0.47, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)

(1S)-(E)-1-(Naphthalen-2-yl)-3-phenylprop-2-en-1-olC19H16OEe = 91%[α]D25=-25.2 (c 0.33, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (S)

(1S)-(E)-1-Cyclohexyl-3-phenylprop-2-en-1-olC15H20OEe = 82%[α]D24=-5.7 (c 0.47, CH2Cl2)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(3R)-(E)-4-Methyl-1-phenylpent-1-en-3-olC12H16OEe = 76%[α]D22=-8.2 (c 0.75, EtOH)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(3R)-(E)-1-Phenylhept-1-en-3-olC13H18OEe = 66%[α]D25=-2.7 (c 0.47, benzene)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(R)-1,2-Diphenylprop-2-en-1-olC15H14OEe = 94%[α]D22=-47.6 (c 0.27, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (R)

(1S)-(E)-1-Phenylhept-2-en-1-olC13H18OEe = 94%[α]D22=+34.2 (c 0.58, CHCl3)Source of chirality: asymmetric synthesisAbsolute configuration: (S)