269. A. Quintard, S. Belot, E. Marchal, A. Alexakis,
     “Aminal-Pyrrolidine Organocatalysts - Highly Efficient and Modular Catalysts for α-Functionalization of Carbonyl Compounds”
     Eur. J. Org. Chem. 2010, 927-936.

The substitution of the 4-position of hydroxyproline by aphenol group, together with an aminal on the 2-position, gave a synergistic effect leading to two powerful complementary organocatalysts. They show excellent enantiocontrol in the α-functionalization of a wide range of linear/branched aldehydes and ketones, including Michael additions to ethenediyl disulfones or nitrostyrene and α-amination. We obtained ees up to 98.5 % with low catalyst loadings (down to 1 mol-%). As a proof of efficiency, TOFs of up to 1000 h^-1 could be obtained.

DOI : 10.1002/ejoc.200901283 

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