Enantioselective Preparation of Secondary Alcohols and Amines

Hyunsoo Han of the University of Texas, San Antonio has described Tetrahedron Lett. 2007, 48,7094) an improved protocol for the enantioselective conversion of primary aUy-Uc carbonates 16 to secondary amines 17. Rene Peters of ETH Zurich has used (Angew. Chem. Int. Ed. 2007,46,7704) a related procedure for the construction of aminated cpiater-nary centers. Mukund P. Sibi of North Dakota State University has devised J. Am. Chem. Soc. 2007,129, 8064) a catalyst for the conjugate addition of the benzyloxyamine 20 to acyl pyrazoles, and Claudio Palomo of the Universidad de Pais Vasco has found (Angew. Chem. Int. Ed. 2007, 46, 8054) that a simple diphenyl prolinol catalyst will effect enantioselective a-amination of aldehydes. 

Carbon-carbon bond formation can also be used to assemble enantiomeiically-pure secondary alcohols. Herfried Griengl of Graz University of Technology has foimd (Adv. Synth. Cat. 2007, 349,1445) that a commercial nitrile lyase effects addition of nitromethane to an aldehyde such as 24 to give the nitro alcohol 25 in high ee. Markus Kalesse of Leibniz Universitat Hannover has constructed a catalyst (Organic Lett. 2007, 9, 5637) for the enantioselective addition of the ketene silyl acetal 27 to aldehydes. Hajime Ito and Masaya Sawamura of Hokkaido University (J. Am. Chem. Soc. 2007,129, 14856) (depicted), and Dennis G. Hall of the University of Alberta (Angew. Chem. Int. Ed. 2007, 46, 5913) have reported complementary enantioselective preparations of allyl boronates such as 31. 

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