Substituent effect on benzylic lithiation of sulfides. Synthesis of diboronic acids derived from aryl-sulfides

Marek Dąbrowski , Krzysztof Durka , Tomasz Kliś , Janusz Serwatowski , Krzysztof Woźniak

Abstract

The relative benzylic deprotonation rate constants of aryl–benzyl sulfides have been measured and the obtained values were compared with the substituent constants using the Hammett equation and with deprotonation Gibbs energies calculated on B3LYP/aug-cc-pVDZ level. The deprotonation rate depends on the stabilization of the negative charge, which is spread over the benzene ring. The series of brominated alkyl–aryl sulfides was di-lithiated by Br/Li exchange using t-BuLi and the obtained organolithium compounds were converted into the respective diboronic acids. Lithiation of aryl–benzyl sulfides containing a bromine atom in the para or ortho positions occurs selectively, however for the meta derivative, the process is plagued by competitive benzylic deprotonation. This fact can be rationalized on the basis of the obtained relative deprotonation rate constants. The X-ray analysis of bis-(2-dihydroxyborylphenylthio)methane revealed the existence of three different structural motifs, which stabilize the structure by hydrogen bonding formation.
Author Marek Dąbrowski (FC / DPC)
Marek Dąbrowski,,
- Department Of Physical Chemistry
, Krzysztof Durka (FC / DPC)
Krzysztof Durka,,
- Department Of Physical Chemistry
, Tomasz Kliś (FC / DPC)
Tomasz Kliś,,
- Department Of Physical Chemistry
, Janusz Serwatowski (FC / DPC)
Janusz Serwatowski,,
- Department Of Physical Chemistry
, Krzysztof Woźniak - [University of Warsaw (UW)]
Krzysztof Woźniak,,
-
- Uniwersytet Warszawski
Journal seriesTetrahedron, ISSN 0040-4020
Issue year2013
Vol69
No15
Pages3159-3166
Publication size in sheets0.5
Keywords in Englishlithiation, boronic acids, sulfides, Hammett equation, ab initio calculations
ASJC Classification1605 Organic Chemistry; 3002 Drug Discovery; 1303 Biochemistry
DOIDOI:10.1016/j.tet.2013.02.075
URL http://www.sciencedirect.com/science/article/pii/S0040402013003013
Languageen angielski
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tetrahedron_2013_69_3159.pdf 634.2 KB
Score (nominal)30
Score sourcejournalList
ScoreMinisterial score = 30.0, 02-02-2020, ArticleFromJournal
Ministerial score (2013-2016) = 30.0, 02-02-2020, ArticleFromJournal
Publication indicators Scopus Citations = 5; WoS Citations = 4; Scopus SNIP (Source Normalised Impact per Paper): 2014 = 0.905; WoS Impact Factor: 2013 = 2.817 (2) - 2013=2.772 (5)
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