- Tetrathiafulvalene-imine-pyridine assemblies for Pb2+ recognition
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A series of donor-π-acceptor systems incorporating a tetrathiafulvalene moiety as the donating unit have been designed and synthesized. The efficiency of the imine (-C=N-) bond as a conjugated π-linker in promoting intramolecular charge transfer is demons
- Balandier, Jean-Yves,Belyasmine, Ahmed,Salle, Marc
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Read Online
- Enhancing catalytic activity of pyridines: Via para -iminophosphorano substituents
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Four pyridines decorated with π-donating iminophosphorano substituents (R3PN-) in the 4-position were assessed as acylation catalysts. These catalysts display high sensitivity to the groups at phosphorus, with activities that are well correlated to the corresponding Hammett-type substituent constants (σp+), and can achieve superior activity over the most active dialkylamino-substituted pyridines. Iminophosphorano-substituted pyridines represent an easily accessible, tunable, and highly active class of nucleophilic organocatalysts. This journal is
- Charlton, Grant D.,Dyker, C. Adam,Richard, Nicholas A.
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p. 9167 - 9171
(2021/11/13)
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- Powerful bispyridinylidene organic reducing agents with iminophosphorano π-donor substituents
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Four members of a new family of powerful bispyridinylidene organic reducing agents have been prepared, which exploit iminophosphorano (-N=PR3; R=Ph, Cy) π-donor substituents. Electrochemical studies show exceptionally high oxidation potentials, ranging from 1.30 to 1.51 V versus SCE. These new reductants were shown to effectively convert 1-bromonaphthalene to naphthalene under mild reaction conditions. From the redox potentials, substituent constants (σp+) for the iminophosphorano groups Ph3P=N- (-1.82) and Cy3P=N- (-2.21) were determined, demonstrating their superior π-donating properties compared to traditional amino substituents. Extra push: Iminophosphorano groups are utilized to significantly increase the reducing power in a new class of neutral, ground state, organic reducing agents (2; see scheme). In comparative reductions involving reductants of type 1 and 2, the latter allow for shorter reaction times and milder conditions. The superb π-donating properties of the studied iminophosphorano groups were quantified by the determination of their Hammett substituent constants.
- Hanson, Samuel S.,Richard, Nicholas A.,Dyker, C. Adam
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supporting information
p. 8052 - 8055
(2015/05/27)
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- Reaction between triphenylphosphine and aromatic amines in the presence of diethyl azodicarboxylate: An efficient synthesis of aryliminophosphoranes under neutral and mild conditions
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An efficient synthesis of aryliminophosphoranes is described. A mixture of an aromatic amine, diethyl azodicarboxylate and triphenylphosphine undergo a Mitsonobu type reaction at ambient temperature in dry dichloromethane to afford aryliminophosphoranes in excellent yields.
- Adib, Mehdi,Sheikhi, Ehsan,Deljoush, Azadeh
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experimental part
p. 4137 - 4140
(2011/06/24)
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- Synthesis of 6H-indolo[2,3-b][1,6]naphthyridines and related compounds as the 5-aza analogues of ellipticine alkaloids
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Treatment of 2-(1-alkynyl)phenyl isocyanates 6 with the iminophosphorane 14 produced in situ the benzoenynyl carbodiimides 15. Thermolysis of 15 under refluxing p-xylene furnished the 6H-indolo[2,3-b][1,6]naphthyridines 5, which could be regarded as the 5-aza analogues of ellipticine alkaloids. Similarly, condensation of 6 with the iminophosphorane 20 led to the formation of the 6H-indolo[2,3-b][1,5]naphthyridines 25 as the major isomer and the 10H-indolo[2,3-b][1,7]naphthyridines 26 as the minor isomer. The indolonaphthyridines 32, 33, and 34 having a methoxyl substituent were likewise synthesized. Treatment of the diisocyanate 43 with 2 equiv of the iminophosphorane 7 furnished 45 having two indoloquinoline units incorporated in a seven-fused-ring system.
- Zhang,Shi,Zhang,Wang
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p. 7977 - 7983
(2007/10/03)
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- Chemistry of Triphenyl-(or Tri-n-butyl-)pyridylphosphonium Salts, 2. - 2,4-Pyridinediylbis(phosphonium) Salts
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2,4-Pyridinediylbis(phosphonium) salts 1 react with nucleophiles to give 4-substituted products 6-8.Under radical reaction conditions the 5-position in 1a is attacked to yield 9.Sodium azide transforms 1a into 8.This salt is used as starting material for
- Anders, Ernst,Markus, Fritz
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p. 119 - 122
(2007/10/02)
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- NEUE METHODE ZUR REGIOSPEZIFISCHEN SUBSTITUTION EINIGER REAKTIONSTRAEGER N-HETEROAROMATISCHER RINGSYSTEME
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N-Trifluoromethanesulfonyl-heteroarylium salts 1 react with phosphanes 2 to give the C4- or C2-substituted products 4 or 5.By means of a similar procedure, bisphosphonium salts 6 and 7 are formed.The reaction of sodium azide (8), and 6 yields the iminophosphorane 10 via the intermediate 9.
- Anders, Ernst,Markus, Fritz
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p. 2675 - 2676
(2007/10/02)
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- 31P-N.M.R. Investigation and Alkylation of N-Hetaryl-triphenylphosphanimides: Estimation of ?--Constants for Several N-Ring Systems from the 31P Chemical Shifts
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On the basis of a Hammett-like relationship we have used the 31P chemical shifts of N-hetaryl-triphenylphosphanimides 2 to estimate ?--constants resp. ?--differences of several N-heteroaromatic rings.The electron-withdrawing influence of these rings on the P chemical shift is additionally increased by a short-range electrical field and magnetic anisotropy effect respectively in case the phosphazene group is linked with the α-position of the hetarene.If one aza substituent is neighbouring to the detector group, this through space effect leads to a downfield shift of about 7 ppm.All compounds are alkylated with methyliodide at the ring N atoms and give the quaternary salts 3.The pyridine-N-oxide derivative 2n exists in the open-chain form and reacts with methyliodide at the O atom.
- Boedeker, J.,Koeckritz, A.,Koeckritz, P.,Radeglia, R.
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p. 723 - 730
(2007/10/02)
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