Superacid-catalyzed chemistry of olefinic pyrazines: A new example of anti-Markovnikov addition

ORGN 648

Douglas A. Klumpp, dklumpp@niu.edu1, Yiliang Zhang, zhangyiliang@yahoo.com1, and Rendy Rendy2. (1) Department of Chemistry and Biochemistry, Northern Illinois University, DeKalb, IL 60115, (2) Department of Chemistry, California State Polytechnic University, 3801 West Temple Aveune, Pomona, CA 91768
Olefinic pyrazines are found to react with benzene in CF3SO3H and give anti-Markovnikov-type addition products. We propose that this is caused by two effects: destabilization of the carbocationic intermediates that would lead to Markovnikov-type products and the generation of a considerable amount of positive charge at the terminal carbon of the olefinic groups. This suggests that acid-catalyzed addition reactions can give anti-Markovnikov-type products when a multiply charged (i.e. superelectrophilic) group is adjacent to the olefinic site.

 

Asymmetric Reactions, Heterocycles, Aromatics, Combinatorial, and Physical Organic Chemistry
8:00 PM-10:00 PM, Wednesday, 31 August 2005 Washington DC Convention Center -- Hall A, Poster

Sci-Mix
8:00 PM-10:00 PM, Monday, 29 August 2005 Washington DC Convention Center -- Hall A, Sci-Mix

Division of Organic Chemistry

The 230th ACS National Meeting, in Washington, DC, Aug 28-Sept 1, 2005