Barbas III

A Knoevenagel condensation/Michael addition sequence has been reported by Barbas III and coworkers (Scheme 2.70) [158] using benzaldehyde, diethyl malonate, and acetone in the presence of the chiral amine (S)-l-(2-pyrrolidinyl-methyl)-pyrrolidine (2-301). As the final product the substituted malonate 2-302 was isolated in 52% yield with 49% ee. 

List/Barbas III (2000) proline and proline analogs iminuim Cataiysis... 

Enantioselective aldol reactions also can be used to create arrays of stereogenic centers. Two elegant ot-amino anion approaches have recently been published. Fujie Tanaka and Carlos F. Barbas III of the Scripps Institute, La Jolla, have shown (Org. Lett. 2004,6,3541) that L-proline catalyzes the addition of the aldehyde 6 to other aldehydes with high enantio- and diastereocontroJ. Keiji Maruoka of Kyoto University has developed (J. Am. Chem. Soc. 2004,126,9685) a chiral phase transfer catalyst that mediates the addition of the ester 9 to aldehydes, again with high enantio- and diastcrcocontrol. 

The current version of the vector is available from C. F. Barbas III at the Research Institute of Scripps Clinic, 10666 North Torrey Pines Road, La Jolla, CA 92037. This vector contains a number of modifications in the promoter regions designed to minimize recombination. In addition, the vector contains two different stuffer fragments (1200 and 300 bp) in the insertion sites, which is an improvement over using the TT antibody clone as the parent vector. 

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