Direct asymmetric aldol reaction co-catalyzed by L-proline and isothiouronium salts

作者：Cho Eun; Kim Taek Hyeon^*

来源：Tetrahedron Letters, 2014, 55(47): 6470-6473.

DOI：10.1016/j.tetlet.2014.10.009

• Aldol reaction
• Asymmetric catalysis
• Isothiouronium salt
• Solvent-free condition

An efficient, simple, and highly selective protocol for the direct asymmetric aldol reaction between cyclohexanone and aromatic aldehydes using L-proline as a chiral catalyst is reported. Catalytic amounts of achiral isothiouronium iodide salt Id have been used for the first time as a co-catalyst for this reaction, which proved to be an excellent catalyst, producing good to excellent yields (up to 93%) with good stereoselectivities (up to 93:7 dr and 99% ee). These aldols are formed under solvent-free catalytic system, inside a standard laboratory refrigerator, and without stirring.

• 出版日期2014-11-19