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Dihalodiazirines and the photochemical generation of dihalocarbenes: new light on old problems
Author(s) -
Moss Robert A.
Publication year - 2010
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1614
Subject(s) - chemistry , diazirine , nitration , photochemistry , computational chemistry , medicinal chemistry , organic chemistry
The Graham oxidation of amidines to halodiazirines, coupled with the diazirine exchange reaction, makes available many new diazirine precursors of carbenes. Nitration of the phenoxy moieties of phenoxychloro‐ or phenoxyfluorodiazirine converts them to leaving groups, ultimately permitting the preparations of CCl 2 , CClF, and CF 2 . Absolute rate constants and activation parameters are measured for the additions of these carbenes to several alkenes. The comparative contributions of Δ H ‡ and Δ S ‡ to Δ G ‡ are assessed for these reactions, as are the dependences of Δ H ‡ and Δ S ‡ on the structures and reactivities of the carbenes and alkenes. Copyright © 2009 John Wiley & Sons, Ltd.