An Efficient Direct Asymmetric Synthesis of 3-Substituted Phthalides

作者：Zhang Zhan Bin; Lu Yong Qin; Duan Xin Fang^*

来源：Synthesis, 2011, (21): 3435-3438.

DOI：10.1055/s-0030-1260222

• phthalide
• magnesiation
• chiral auxiliary
• diastereoselective addition
• asymmetric synthesis

A facile, two-step, asymmetric synthesis of 3-substituted phthalides has been developed. The enantiopure amide, obtained through coupling of 2-iodobenzoic acid with (S)-1-(pyrrolidin-2-yl-methyl)-1H-imidazole, was magnesiated using isopropylmagnesium chloride. Corresponding reactions with a range of aldehydes were carried out in situ by either direct addition or transmetallation using zinc(II) chloride. Intramolecular esterification of the adduct allowed the versatile asymmetric synthesis of phthalides in up to 88% enantiomeric excess.

• 出版日期2011-11
• 单位北京师范大学