- Insertion of CS2 into iridium-fluorine bonds
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CS2 jumps in: C-F bond formation occurs by reactions of the fluorido complexes trans-[Ir(ArF)(F)(H)(PiPr3) 2] (ArF=4-C5NF4; see scheme) with CS2 to form the fluorodith
- Klaering, Paul,Braun, Thomas
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Read Online
- Fluoro-Substituted Methyllithium Chemistry: External Quenching Method Using Flow Microreactors
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The external quenching method based on flow microreactors allows the generation and use of short-lived fluoro-substituted methyllithium reagents, such as fluoromethyllithium, fluoroiodomethyllithium, and fluoroiodostannylmethyllithium. Highly chemoselective reactions have been developed, opening new opportunities in the synthesis of fluorinated molecules using fluorinated organometallics.
- Colella, Marco,Degennaro, Leonardo,Higuma, Ryosuke,Ishikawa, Susumu,Luisi, Renzo,Nagaki, Aiichiro,Takahashi, Yusuke,Tota, Arianna
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p. 10924 - 10928
(2020/05/08)
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- Synthesis and reactivity of dinuclear rhodium complexes with Rh=C=CHR and Rh=C=C=CRR′ units as building blocks
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The reaction of [Rh{κ2-O2S(O)CF3} (PiPr3)2] (1) with ethynylferrocene in the presence of KF affords the substituted vinylidene complex trans-[RhF{=C=CH(C5H4) Fe(C5 H5)}(PiPr3)2] (2) which upon treatment with the butadiyne derivative Ph3SnC≡ C-C≡CSnPh3 produces the chain-like compound trans-[(μ-C≡C-C≡C){Rh(=C=CH (C5H4)Fe(C5H5))(Pi Pr3)2}2] (7). The triflato complex 1 reacts with 1,4-C6H4(C≡CH)2 to give the dinuclear compound trans-[{μ-1,4-C6H4 (CH=C=)2}{Rh(η1-OS(O) 2CF3)(PiPr3)2} 2] (3) which in the presence of KF undergoes a ligand exchange to give the corresponding difluoro derivative 4. From 4 and RC≡ CSnPh3 (R=CH3, C6H5) the complexes 5 and 6, in which a C6H4 unit bridges two alkynyl(vinylidene)rhodium(I) fragments, are obtained. Both 6 and 7 react with CO by migratory insertion of the vinylidene units into the alkynyl-metal bonds to afford the dinuclear complexes 8 and 9, in which an unusual C8 or C4(C6H4) C4 chain bridges the two rhodium centers. The reactions of [RhCl(PiPr3)2]2 (10) with the functionalized diynes 1,1′,4,4′-C6 H4(OH)2(C≡CH)2 and 1,4-C6H4[C(Ph)(OH)C≡CH]2 lead, via the corresponding diyne-metal species 11 and 12 as intermediates, to the formation of the bis(vinylidene) complexes 13 and 14, the latter of which reacts with acidic Al2O3 by elimination of water to give the novel phenylene-bridged bis(allenylidenerhodium) compound [{μ-1,4-C6H4(CPh=C= C=)2}{RhCl(PiPr3)2} 2] (15) in 80% yield.
- Callejas-Gaspar, Berta,Laubender, Matthias,Werner, Helmut
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p. 144 - 152
(2007/10/03)
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- Methylene-bridged tri- and tetratin compounds as Lewis acids
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Syntheses of a series of trinuclear tin compounds, (Ph2XSnCH2)2SnXPh (2, X = Ph; 6, X = F; 8, X = Cl) and (PhCl2SnCH2)2SnCl2 (10) and tetranuclear tin compounds (Ph2XSnCH2-SnXPh)2CH2 (3, X = Ph; 7, X = F; 9, X = Cl) are reported, and the crystal structure of [(Ph2FSnCH2)2SnFPh·F]-[C 12H24O6·K]+ (6b) is described. Variable temperature 119Sn and 19F NMR studies indicate that the structure observed for the anion in 6b in the solid state is retained in solution. There is no NMR evidence for the formation of 1:2 adducts with fluoride ion, although such species are identified in acetonitrile solutions from electrospray mass spectrometry (ESMS). 119Sn NMR spectral data indicate that reaction of trinuclear tin compound 8 with [(Ph3P)2N]+Cl- and HMPA results in formation of the 1:1 complexes [(Ph2ClSnCH2)2SnClPh·Cl] -[(Ph3P)2N]+ (8a) and (Ph2ClSnCH2)2SnClPh·[(CH 3)2N]3PO (8b), respectively. In contrast, 19F and 119Sn NMR data show that the tetranuclear tin compound 7 reacts with fluoride ion to give a stable 1:2 adduct [(Ph2FSnCH2SnFPh)2CH 2·2F]2-2[Bu4N]+ (7b) in solution, being no NMR evidence for formation of a 1:1 adduct. However, ESMS indicates the presence of both 1:1 and 1:2 adducts in acetonitrile solution.
- Altmann, Reiner,Jurkschat, Klaus,Schürmann, Markus,Dakternieks, Dainis,Duthie, Andrew
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p. 5716 - 5723
(2008/10/08)
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- Solid-state 119Sn NMR studies of coordination in triorganyltin fluorides
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High-resolution 119Sn spectra of solid trimethyltin fluoride (I), tri-isobutyltin fluoride (II), and triphenyltin fluoride (III) show that all the compounds are five-coordinate in the solid state, with the 119Sn nucleus apparently equally coupled to two f
- Bai, Haiping,Harris, Robin K.,Reuter, Hans
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p. 167 - 172
(2007/10/02)
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- Synthesis, Reactivity and Spectral Studies of Some Pentacoordinate Tin(IV) Complexes Derived from Triphenyltin Trifluoroacetate
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Triphenyltin methoxide/ethoxide prepared in situ reacts with trifluoroacetic acid, yielding triphenyltin trifluoroacetate in quantitative yield.The reactions of Ph3SnOCOCF3 with tetraalkylammonium salts (R4NX) give pentacoordinated Sn(IV) complex anions of the general formulae (+)(-) .Ph3SnOCOCF3 undergoes cleavage with electrophilic reagents such as ICl, IBr, HgCl2, Hg(SCN)2, yielding Ph2Sn(OCOCF3)*X (X=Cl, Br, SCN).These compounds like the parent Ph3SnOCOCF3 are polymeric in nature with five coordinated Sn(IV) atoms and bridging trifluoroacetate groups.These undergo nucleophilic substitution of (X) with other electronegative groups and form 1:1 molecular adducts with common Lewis bases.All these compounds have been characterized by elemental analyses, and IR and PMR data.
- Srivastava, T. N.,Singh, Jai Deo
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p. 489 - 492
(2007/10/02)
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- SYNTHESIS AND 1H NMR STUDIES OF SOME PENTACOORDINATE TIN(IV) COMPLEXES DERIVED FROM TRIPHENYLTIN HALIDES
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Several anionic-cationic and neutral pentacoordinate tin(IV) complexes were prepared by the reaction of triorganotin(IV) halides, R3SnX (R=Me and X=Cl; R=Ph and X=F, Cl, Br) with tetraalkylammonium halides and neutral ligands (pyridine, 4-(dimethylamino)pyridine, hexamethylphosphoramide and triphenylphosphine oxide).The complexes were examined in solution by 1H NMR spectroscopy and characterized as having trigonal bipyramidal geometry around tin where the phenyl groups occupy the equatorial sites and more electronegative ligands are at axial positions.The 1H NMR spectra of these comlexes showed two distinct sets of aromatic multiplets arising from ortho-protons at low field, and meta- and para-protons at high field.A possible rationale has been offered for this observation.The upward shift of the tetraalkylammonium proton resonances in the phenyl-substituted complexes has been postulated to arise from shielding caused by the aromatic ring.
- Sau, Arjun C.,Carpino, Louis A.,Holmes, Robert R.
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p. 181 - 198
(2007/10/02)
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