Connective Stereospecific Generation of Alkenes

Oregon State University, Corvallis OR

Investigators

Abstract

The Chemical Synthesis Program of the NSF Chemistry Division supports the research of Professor Paul Blakemore in the Department of Chemistry, Oregon State University (OSU). Professor Blakemore and his students are exploring a new method for the preparation of alkenes, a class of carbon-based molecules. These substances are of value to many fields including medicine, agriculture, and engineering. Alkenes can exist in either of two geometrical forms. It is essential to control which form of an alkene is prepared because the two types have different physical and biological properties. The chemical reactions developed at OSU enable either geometrical form of an alkene to be made selectively. This research advances the education of students spanning levels of experience from high school, to undergraduate, to graduate, and post-doctoral. In addition, Professor Blakemore foster the participation of students from groups that are traditionally underrepresented in the physical sciences. This research introduces a new approach for stereocontrolled alkene synthesis based on eliminative cross-coupling of enantioenriched sp3-hybridized carbenoids. By contrast to traditional strategies for alkene synthesis, which cannot wholly control stereochemistry, the method developed in this research does not rely on differentiated substituents to bias generation of one isomer over the other. Rather, interplay between pre-existing absolute stereochemical features within the carbenoid subunits is exploited to steer formation of the carbon-carbon double bond toward the desired stereoisomer. To explore the scope of this new method while demonstrating its relevance to society, complex alkene containing bioactive compounds are prepared alongside simpler models. These include a P-glycoprotein stimulator (a potential therapeutic for Alzeheimer's disease), vitamin D3 (a secosteroid with multiple applications), and pumiliotoxin 251D (an alkaloid with sodium ion channel activity). The next generation of scientists is nurtured. High school students participating in statewide summer internship programs are hosted within Professor Blakemore's laboratory.