1162-70-5Relevant articles and documents
Synthetic access and luminescence tuning in a series of β-H and β-silyl substituted phospholes
Klintuch, Dieter,Kirchmeier, Andreas,Bruhn, Clemens,Pietschnig, Rudolf
, (2020/04/27)
Starting from substituted 1,3-diynes a straightforward strategy to prepare phospholes has been explored for a series of substituents with electron poor and electron rich character (C6H5, C6H4CF3, C6F4OCH3, C5H4N, C4H3S, C4H3O, C6H4OCH3). The reaction involves formal addition of PhPTMSLi to the diyne resulting in the respective β-silyl phosphole bearing the substituents of the diyne in the α-positions. Subsequent desilylation afforded the corresponding β-H substituted phospholes which otherwise are difficult to obtain or inaccessible. The β-H phospholes showed attractive luminescence features including high quantum yields. Their β-silyl analogs revealed hypsochromic shifts in their absorption bands as a consequence of reduced coplanarity of the adjacent rings in vicinity of the silyl unit owing to steric repulsion. The structure property relationship was established on structural data from the solid state, quantum chemical DFT calculations and experimental UV vis and luminescence spectra. The identity of all new compounds was established using multinuclear NMR, mass spectrometry, elemental analysis and XRD where available.
New pinene-derived pyridines as bidentate chiral ligands
Malkov, Andrei V.,Stewart-Liddon, Angus J.P.,Teply, Filip,Kobr, Luká?,Muir, Kenneth W.,Haigh, David,Ko?ovsky, Pavel
, p. 4011 - 4025 (2008/09/20)
A synthesis of new bidentate pyridines 8a-d, 9, and 10 has been developed, starting from triflate 14, readily available from β-pinene 11. A copper complex of the pyridine-oxazoline ligands 8a has been found to catalyze asymmetric allylic oxidation of cyclic olefins 36a-c with good conversion rates and acceptable enantioselectivity (≤67% ee). The imidazolium salt 10 has been identified as a precursor of the corresponding N,N′-unsymmetrical N-heterocyclic carbene ligand, whose complex with palladium catalyzed the intramolecular amide enolate α-arylation leading to oxindole 45 in excellent yield but with low enantioselectivity.
MOESSBAUER STUDIES ON FERROCENE COMPLEXES. IX. PHOSPHAFERROCENES AND THEIR PROTONATED DERIVATIVES
Lukas, B.,Roberts, R. M. G.,Silver, J.,Wells, A. S.
, p. 103 - 110 (2007/10/02)
A number of mono- and di-phosphaferrocenes have been synthesised and their NMR (1H, 31P) and Moessbauer spectra measured.The presence of a phosphorus atom in the cyclopentadienyl (Cp) moiety causes a reduction of about 0.3 mm s-1 in the quadrupole splitting (QS) compared with that of ferrocene.The effect appears to be additive, as does the effect of Cp ring substituents.Thus 2,5-diphenylphosphaferrocene (I), 3,3',4,4'-tetramethyldiphosphaferrocene (II) and 2,2',5,5'-tetraphenyldiphosphaferrocene (III) have QS values of 2.03, 1.82 and 1.52 mm s-1, respectively.III dissolves readily and reversibly in triflic acid (CF3SO3H) to give a phenyl ring protonated species.The Moessbauer spectrum of the frozen solution shows a significant increase in QS to 1.77 mm s-1 which is interpreted in terms of iron participation in the stabilisation of the ? complex.H/D exchange reactions and oxidation of phosphaferrocenes are briefly reported together with an improved synthesis of the important precursor, 1,2,5-triphenylphosphole.
