A structurally simple l-proline derivative promotes the asymmetric allylation of aldehydes with tribromoallyltin

An asymmetric allylation of aldehydes with the allyltin tribromide was achieved using the l-proline derivative as a chiral promoter in dichloromethane in the presence of a Lewis base. Various optically active homoallylic alcohols were obtained in high yields with moderate enatioselectivities of up to 62% ee.

Figure optionsDownload as PowerPoint slide

(R)-(+)-1-Phenyl-3-buten-1-olC10H12O[α]D20=+22.3 (c 2, benzene)Absolute configuration: (R)

(R)-(+)-1-(p-Chlorophenyl)-3-buten-1-olC10H11ClO[α]D20=+15.5 (c 2.4, benzene)Absolute configuration: (R)

(R)-(+)-1-(p-Fluorophenyl)-3-buten-1-olC10H11FO[α]D20=+21.5 (c 2, CHCl3)Absolute configuration: (R)

(R)-(+)-1-(p-Bromophenyl)-3-buten-1-olC10H11BrO[α]D20=+12.6 (c 3.5, benzene)Absolute configuration: (R)

(R)-(+)-1-(p-Methylphenyl)-3-buten-1-olC11H14O[α]D20=+15.5 (c 2, benzene)Absolute configuration: (R)

(R)-(+)-1-(p-Methoxyphenyl)-3-buten-1-olC11H14O2[α]D20=+15.4 (c 2, benzene)Absolute configuration: (R)

(R)-(+)-1-(p-Trifluorophenyl)-3-buten-1-olC11H14F3O[α]D20=+14.2 (c 1.7, CHCl3)Absolute configuration: (R)