Highly enantioselective reduction of pyridyl alkyl ketone O-benzyl oxime ethers catalyzed by spiroborate ester: Application to the synthesis of nicotine analogs

ORGN 608

Kun Huang, huangkun7211@hotmail.com1, Margarita Ortiz-Marciales, m_ortiz@cuhac.upr.clu.edu2, and Viatcheslav Stepanenko, the3spiritslava@hotmail.com2. (1) Department of Chemistry, University of Puerto Rico at Humacao, Estacion Postal CUH, 100 Carr. 908, Humacao, PR 00791-4300, (2) Department Of Chemistry, University of Puerto Rico- Humacao, CUH Station, Humacao, PR 00791
Asymmetric synthesis of nonracemic pyridyl alkyl amines is an important step in the preparation of many biological compounds. A detailed study to assess the enantioselective reduction of pyridyl alkyl O-benzyloxime ethers catalyzed by spiroborate ester derived from (S)-diphenyl-L-valinol and ethylene glycol has been carried out. Effects of reaction conditions on the enantioselective reduction were investigated and effective catalytic conditions were achieved for the first time. High yields and excellent enatiometic excess (95-99% ee) were obtained using 30% of catalyst loading in dioxane at 10 ºC. The nicotine analogue 2 was synthesized from starting material 1 in good chemical yield and 97% ee.

 

Materials, Devices and Switches, Metal-Mediated Reactions, Asymmetric Reactions, Total Synthesis, Biologically-Related Molecules and Processes
7:00 PM-9:00 PM, Wednesday, April 9, 2008 Morial Convention Center -- La Louisiane, Blrm. C, Poster

Division of Organic Chemistry

The 235th ACS National Meeting, New Orleans, LA, April 6-10, 2008