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ERIC Number: EJ820317
Record Type: Journal
Publication Date: 2006-Nov
Pages: 5
Abstractor: As Provided
Reference Count: 13
ISBN: N/A
ISSN: ISSN-0021-9584
Polar Addition to C=C Group: Why Is Anti-Markovnikov Hydroboration-Oxidation of Alkenes Not "Anti-"?
Ilich, Predrag-Peter; Rickertsen, Lucas S.; Becker, Erienne
Journal of Chemical Education, v83 n11 p1681-1685 Nov 2006
For 137 years Markovnikov's rule has been extensively used in organic chemical education and research to describe the regioselectivity in electrophilic addition reactions to alkenes and alkynes. When the structures of the final reaction products are used as reference, the rule requests that certain polar addition reactions be termed anti-Markovnikov. We use first principles thermodynamic calculations to analyze six polar addition reactions to alkenes, expected to be of either Markovnikov or anti-Markovnikov regioselectivity. Our results show no difference between the two reaction types: in each case the alkene atomic charges and the form of the intermediate completely determine the course of the overall reaction and the form of the predominant final product. We redefine this type of regioselectivity and propose that teaching of organic chemistry should be based more on robust and portable concepts such as energy difference and atomic charge than on historical labels. (Contains 3 figures, 1 scheme, 1 table, and 3 notes.)
Division of Chemical Education of the American Chemical Society. Subscription Department, P.O. Box 1267, Bellmawr, NJ 08099-1267. Tel: 800-691-9846; Tel: 856-931-5825; Fax: 856-931-4115; e-mail: jchemed@egpp.com; Web site: http://www.jce.divched.org
Publication Type: Journal Articles; Reports - Evaluative
Education Level: Higher Education; Postsecondary Education
Audience: Teachers
Language: English
Sponsor: N/A
Authoring Institution: N/A