Phosphorus, Sulfur, and Silicon, 186:769–771, 2011
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Taylor & Francis Group, LLC
C
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426507.2010.499549
N-PHOSPHORYL-2-OXO-1,2-AZAPHOSPHOLANES:
FIRST EXAMPLE OF CYCLIC O,O-BIDENTATE LIGANDS
WITH THE P-N-P BACKBONE
Inga M. Aladzheva, Olga V. Bykhovskaya, Yulya V. Nelyubina,
Pavel V. Petrovskii, and Irina L. Odinets
A. N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy
of Sciences, Moscow, Russia
Abstract A convenient one-pot synthesis of N-phosphoryl-2-oxo-1,2-azaphospholanes was
developed starting from commercially available or simple-to-prepare phosphorus (III) acid
chlorides and 3-bromopropylamine. The compounds readily form complexes with f-elements of
ML, ML2, and M2L3 composition including (µ2-peroxo)-bridged uranium complexes, depend-
ing on both the ligand and metal nature.
Keywords 1,2-Azaphospholanes; complexes; ligands
Bidentate chelate ligands with the P-N-P backbone in which oxygen or sulfur atoms of the
phosphoryl groups serve as coordination sites are known to coordinate to a number of met-
1
2
als. Some ligands of this type are useful as selective metal extractants or find application as
3
4
NMR shift reagents, and their lanthanide complexes possess high luminescent properties,
5
whereas silver and palladium ones are promising for homogeneous catalysis. Note that all
such ligands known until now present linear compounds, whereas cyclic ligands are known
to be advantageous for selectivity over the complex formation. Therefore, we have devel-
oped facile cascade synthesis of cyclic ligand systems with a P-N-P backbone 3a–c based
on an intramolecular Arbuzov reaction of N,N-bis-P(III)-substituted 3-bromopropylamines
1a,b, generated in situ from phosphorus (III) acid chlorides, followed by either oxidation or
the second intermolecular Arbuzov reaction of the intermediate 2-oxo-1,2-azaphospholanes
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2
a,b (Scheme 1). In the case of compounds 3b,c having two chiral P-atoms, the diastere-
omers were separated by column chromatography. A comparison of X-ray and NMR data
∗
∗
allowed us to conclude that the opposite configuration of asymmetric centers (R ,S ) is
typical for the isomer having downfield chemical shift of the endocyclic P-atom in the
3
1
P-NMR spectra and smaller JP-P coupling constant.
-Oxo-1,2-azaphospholanes 3a–c readily form complexes with f-elements in neutral
media. Depending on the nature of both the ligand and metal, the isolated complexes
2
∗
∗
differ in composition (ML, ML2, and M2L3). Thus, reacting with Eu(III) nitrate, R ,S -
3
3
b afforded the [Eu(L2)(NO3)3] complex, that is, ML2, whereas both diastereomers of
c form with Eu(III), Nd(III), and Pr(III) nitrates complexes [Ln2L3(NO3)6], regardless
Received 1 June 2010; accepted 6 June 2010.
Address correspondence to Irina L. Odinets, A. N. Nesmeyanov Institute of Organoelement Compounds,
RAS, 28 Vavilova Street, Moscow 119991, Russian Federation. E-mail: odinets@ineos.ac.ru
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