alpha-Fluoro-alpha-nitro(phenylsulfonyl)methane as a fluoromethyl pronucleophile: Efficient stereoselective Michael addition to chalcones

作者：Prakash G K Surya^*; Wang Fang; Stewart Timothy; Mathew Thomas; Olah George A

来源：Proceedings of the National Academy of Sciences, 2009, 106(11): 4090-4094.

DOI：10.1073/pnas.0900179106

• fluorinated substituents
• H bonding
• stereoselective catalysis
• steric effect

Highly efficient stereoselective 1,4-addition of racemic alpha-fluoro-alpha-nitro(phenylsulfonyl) methane (FNSM) as a fluoromethyl pronucleophile to alpha,beta-unsaturated ketones using a wide range of chiral organobifunctional catalysts under moderate conditions in the absence of an additional base has been achieved. A series of catalysts was screened for the enantioselective addition of FNSM to chalcones and the catalysts CN I, CD I, QN I-IV, and QD I were found to enable this reaction, successfully providing exclusive 1,4-addition products stereoselectively in high yields (conversion, diastereomeric ratio, and enantiomeric excess). Studies involving a model reaction and systematic analysis of the absolute configuration support the suggested mechanism.

• 出版日期2009-3-17