4th EucheMs chemistry congress

Poster Session 2
s1280
chem. Listy 106, s257–s1425 (2012)
Poster session 2 - organic chemistry
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SoMe AqueouS CheMiStry of the
thioPhoSPhoryL GrouP
L. ConwAy 1 , M. trMCiC 1 , r. deLLey 1 ,
J. norCLiffe 1 , d. hodGSon 1
1 Durham University, Chemistry, Durham, United Kingdom
the Aqueous reduction of Azides using Sodium
thiophosphate: We present a clean, aqueous method for the
conversion of azides to amines with trisodium thiophosphate as
the reducing agent. [1] The transformation is shown to be effective
on a range of alkyl and aryl substrates.
thiophosphoryl ‘Click’ Chemistry: Our group has
developed a one-pot synthesis allowing two organic groups to be
conjugated by a thiophosphoramidate linker. [2] The reaction has
been tested on a range of substrates and has been found to be
widely applicable. The method shows high levels of conversion
and generates innocuous by-products. This chemistry has potential
as a mimic of phosphate-containing biological systems, and as an
example of this, we have applied the methodology to the synthesis
of a thymidyl-(3'-5')-thymidine thiophosphoramidate analogue
with a view to studying the hydrolytic properties of this system.
references:
1. J. L. Norcliffe, L. P. Conway, and D. R. W. Hodgson,
Tetrahedron Lett., 2011, 52, 2730-2732
2. M. Trmcic and D. R. W. Hodgson, Chem. Comm., 2011,
47, 6156-6158
Keywords: Aqueous; Azide; Phosphate; Thiophosphate;
4 th EucheMs chemistry congress
P - 0 8 3 5
reACtivitieS of ethyL AryLACetAte AnionS
f. CorrAL BAutiStA 1 , h. MAyr 1
1 Ludwig-Maximilians-Universität, Chemie, München, Germany
The anions of ethyl arylacetates are frequently used as
nucleophiles in Michael additions and Claisen condensations.
Furthermore, they can easily be alkylated or added to carbonyl
groups, imines, or acetylenes leading to a wide variety of products
of biological and medicinal interest.
Kinetic investigations of the reactions of the anions of ethyl
arylacetates with quinone methides and diethyl
benzylidenemalonates in DMSO allowed us to quantify their
nucleophilic reactivities according to the linear free energy
relationship eq [1] , in which electrophiles are characterized by one
parameter E and nucleophiles are characterized by
the solvent-dependent parameters s (sensitivity) and
N
N (nucleophilicity). 1
lg k (20 °C) =s (N + E) (1)
2 N
Our investigations show that the nucleophilic reactivities of
these compounds are highly affected by the substitution pattern
of the aromatic ring. Their nucleophilicities are comparable to
those of the anions of phenyl acetonitriles. [2] The title compounds
thus belong to the most reactive nucleophiles so far studied by
our group and can be used to characterize very weak electrophiles.
references:
1. H. Mayr, T. Bug, M. F. Gotta, N. Hering, B. Irrgang,
B. Janker, B. Kempf, R. Loos, A. R. Ofial, G. Remennikov,
H. Schimmel, J. Am. Chem. Soc. 2001, 123, 9500–9512.
2. For a comprehensive listing of nucleophilicity parameters
N, s and electrophilicity parameters E,
N
see www.cup.uni-muenchen.de/oc/mayr/DBintro.html.
Keywords: Kinetics; Carbanions; Linear free energy
relationship;
AUGUst 26–30, 2012, PrAGUE, cZEcH rEPUbLIc