Enantioselective Construction of Alkylated Stereogenic Centers

Conjugate addition of stabilized carbanions can also be carried out with high enantiocon-trol. David A. Evans of Harvard University has described (J. Am. Chem. Soc. 2007, 129, 11583) the Ni-catalyzed addition of malonate 15 to nitroalkenes such as 14. Claudio Palomo of the Universidad de Pais Vasco (Angew. Chem. Int. Ed. 2007, 46, 8431) and concurrently Yujito Hayashi of the Tokyo University of Science (Organic Lett. 2007, 9, 5307) have developed organocatalytic protocols for the addition of nitromethane 18 to unsaturated aldehydes such as 17. 

Michael Chong of the University of Waterloo has found (J. Am. Chem. Soc. 2007, 129, 4908) that the Binol-mediated enantioselective conjugate addition of alkenylboronic acids such as 22 required the additional activation of the aryl ketone. Shun-Jun Li of 

Benjamin List of the Max-Planck-Institut, Mulheim has taken advantage J. Am. Chem. Soc. 2007, 129, 11336) of the large-small differential of the substituents on the aldehyde 28. Enantioselective Pd-mediated rearrangement of the protonated enamine derived from condensation of 28 with 29 delivered the aldehyde 30 in high ee. 

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