In:
European Journal of Organic Chemistry, Wiley, Vol. 2009, No. 30 ( 2009-10), p. 5153-5161
Abstract:
The photoacetylation of diamondoids (nanodiamonds), in particular [1212]pentamantane, [1(2,3)4] pentamantane, and [123]tetramantane, with diacetyl almost exclusively gives apical acetyl derivatives. The mechanism of the photoacetylation was studied on the basis of a comparative analysis of the experimental deuterium kinetic isotope effects as well as the observed C–H bond substitution selectivities, which were also computed at the B3LYP, B3PW91, and MP2 levels of theory including polarized continuum modeling of solvent effects. The high apical C–H bond selectivities in the photoacetylation of diamondoids are determined by the higher polarizabilities of the cages along the apical direction in the transition structures for hydrogen abstraction with the triplet diacetyl diradical. Steric effects play only a minor role, and in combination with solvation, outweigh charge‐transfer effects that usually favor medial substitution with electrophiles and electrophilic radicals.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Type of Medium:
Online Resource
ISSN:
1434-193X
,
1099-0690
DOI:
10.1002/ejoc.v2009:30
DOI:
10.1002/ejoc.200900600
Language:
English
Publisher:
Wiley
Publication Date:
2009
detail.hit.zdb_id:
1475010-7
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