1454-80-4Relevant articles and documents
Development of 7-membered N-heterocyclic carbene ligands for transition metals
Scarborough, Christopher C.,Popp, Brian V.,Guzei, Ilia A.,Stahl, Shannon S.
, p. 6143 - 6155 (2005)
We recently reported the first example of a seven-membered N-heterocyclic carbene (NHC) ligand for transition metals. These ligands are attractive because the heterocyclic framework, derived from 2,2′-diaminobiphenyl, exhibits a torsional twist that results in a chiral, C2-symmetric structure. The present report outlines the synthetic efforts that led to the development of these ligands together with the synthesis and structural characterization of metal complexes bearing seven-membered NHCs as ancillary ligands. The identity of nitrogen substituent, neopentyl versus 2-adamantyl, influences the synthetic accessibility and stability of the seven-membered amidinium salts and the NHC-metal complexes obtained via in situ deprotonation/metallation. Computational analysis of the seven-membered ring structures reveals the Hückel antiaromatic 8π electron system achieves significant M?bius aromatic stabilization upon undergoing torsional distortion of the heterocyclic ring.
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Ross et al.
, p. 4122,4123 (1952)
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Formation of 1,10-Disubstituted Benzo[c]cinnolines. Synthesis and Molecular Structure of 1-Amino-10-propylthiobenzo[c]cinnoline and Cyclization to 4-Propylcinnolino[5,4,3][c,d,e][1,2]benzothiazine
Benin, Vladimir,Kaszynski, Piotr,Pink, Maren,Young Jr., Victor G.
, p. 6388 - 6397 (2000)
The first 1,10-heterodisubstituted benzo[c]cinnoline derivative 1 was prepared from the trinitrobiphenyl 2. Investigation of the mechanism of ring closure in 2, 5, and 8 revealed a complex reduction-oxidation-cyclization sequence. The mechanism is discussed in light of the stereoelectronic demands of the substituent functionalities. Benzo[c]cinnoline derivative 1 [C15H15N3S, monoclinic, P21/c: a = 7.4063(3) A, b = 10.3739(5) A, c = 16.7642(8) A, β = 91.816(1)°, Z = 4] and its 5-N-oxide 7(N5) [C18H18N3OS, triclinic, P1: a = 8.1510(7) A, b = 8.6106(7) A, c = 12.102(1) A, α = 86.262(1)°, β = 83.364(1)°, γ = 74.711(1)°, Z = 4] were structurally characterized and showed a significant helical distortion of the heterocyclic ring. Oxidation of 1 with NCS or triamine 12 with PhI(OAc)2 led to a new heterocyclic ring system, ylide 13. Both benzo[c]cinnoline 1 and ylide 13 were characterized spectroscopically and the absorption spectra were correlated with the results of ZINDO calculations.
Macrocyclic [Cu(I/II)(bite)](+/2+) (bite = biphenyldiimino dithioether): An example of fully-gated electron transfer and its biological relevance
Flanagan, Scott,Dong, Jun,Haller, Kenneth,Wang, Shengke,Scheidt, W. Robert,Scott, Robert A.,Webb, Thomas R.,Stanbury, David M.,Wilson, Lon J.
, p. 8857 - 8868 (1997)
Template condensation of 2,2'-diaminobiphenyl, 1,4-bis(2-formylphenyl)-1,4-dithiabutane, and copper(II) tetrafluoroborate yields the new macrocyclic compound [Cu(I)(bite)l(BF4) (bite = biphenyldiimino dithioether). [Cu(I)(bite)]BF4 c
Biphenyl Bis(amino alcohol) Oxalamide Gelators: Complex Gelation Involving Coupled Equilibria, Central-to-Axial Chirality Transfer, Diastereoisomer Interconversion, and Self-Sorting
Portada, Tomislav,Mol?anov, Kre?imir,?ijakovic Vuji?ic, Nata?a,?inic, Mladen
, p. 1205 - 1214 (2016)
Chiral gelators 3 and 4, with two valinol- or leucinol-oxalamido arms attached to the 2,2′-positions of the proatropisomeric biphenyl group, were prepared, and their gels were studied. Compound (R,R)-3 in the solution and gel states forms a mixture of major [(R,aR,R)-3] and minor [(R,aS,R)-3] diastereomers due to central-to-axial chirality transfer. 1H NMR studies of its toluene gel provide evidence of diastereomer interconversion and self-sorting, which results in exclusive incorporation of (R,aR,R)-3 into the gel network. Gels formed in the 10-3 M concentration range show an irregular Tg/concentration dependence, which is in contrast to those formed in the 10-2 M concentration range. The peculiar properties of the former gels may be explained by kinetic effects due to the presence of coupled equilibria comprising diastereomer interconversion and (R,aR,R)-3 self-assembly where the rate of gelation becomes dependent on the rate of formation of the gelling (R,aR,R)-3 from the nongelling (R,aS,R)-3.
Hein,Jehn
, p. 244,250 (1965)
Poly(3,6-silafluorene-co-2,7-fluorene)-based high-efficiency and color-pure blue light-emitting polymers with extremely narrow band-width and high spectral stability
Wang, Ergang,Li, Chun,Mo, Yueqi,Zhang, Yong,Ma, Gang,Shi, Wei,Peng, Junbiao,Yang, Wei,Cao, Yong
, p. 4133 - 4140 (2006)
A new series of copolymers (PSiFF) based on 3,6-silafluorene and 2,7-fluorene were synthesized via the Suzuki polycondensation. The influences of the 3,6-silafluorene content in the copolymers on the thermal, photophysical, electroluminescence and electrochemical properties were investigated. The incorporation of 3,6-silafluorene into the polyfluorene main chain not only suppressed the long-wavelength emission but significantly improved the efficiency and color purity of the copolymer-based devices. Both fluorene and 3,6-silafluorene took part in π-conjugation of the main chain and the electroluminescence spectra were remarkably blue-shifted with increasing wide bandgap 3,6-silafluorene content. The device based on PSiFF90 with the configuration of ITO/PEDOT: PSS/PVK/polymer/Ba/Al showed a quantum efficiency of 3.34% and a luminous efficiency of 2.02 cd A-1 at a brightness of 326 cd m-2 with CIE 1931 chromaticity coordinates of (0.16, 0.07), which almost match the NTSC standard blue pixel coordinates of (0.14, 0.08). Moreover, the incorporation of 3,6-silafluorene into the polyfluorene main chain significantly improved the spectral stability at annealing. The results indicate poly(3,6-silafluorene-co-2,7-fluorene) could be a promising candidate for blue-emitting polymers of high efficiency and good color purity. The Royal Society of Chemistry 2006.
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Blood,Noller
, p. 711 (1957)
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Highly Chemoselective Access to 2,2-Diaminobiaryls via Ni-Catalyzed Protecting-Group-Free Coupling of 2-Haloanilines
Long, Cheng-Yu,Ni, Shao-Fei,Su, Min-Hui,Wang, Xue-Qiang,Tan, Weihong
, p. 13641 - 13649 (2020)
The development of strategies to access 2,2-diaminobiaryl derivatives via a transition-metal-catalyzed coupling reaction from protecting-group-free starting materials is a challenging task to accomplish, owing to the easy occurrence of undesired side reactions. The exploitation of Ni-catalyzed direct homocoupling of unprotected 2-haloaniline analogues to produce 2,2-diaminobiaryls with a readily available and inexpensive bipyridine ligand has been described. This approach was highlighted by its high chemoselectivity, broad substrate scope, and functional group compatibility. The mechanistic and calculation studies indicated that Ni(0), Ni(I), Ni(II), and Ni(III) species might be involved in the catalytic cycle.
Asymmetric activation of the tropos biphenyldiamidophosphite moiety: Synthesis and complexation to rhodium of a deoxycholic acid derived diamidophosphite
Iannucci, Grazia,Iuliano, Anna
, p. 88 - 94 (2016)
A tropos deoxcholic acid derived diamidophosphite was synthesised starting from deoxycholic acid and N,N′-dimethyl-2,2′-diamino-1,1′biphenyl and its stereodinamic characteristics were assessed by VT-NMR spectroscopy. The capability of the diamidophosphite
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Moore,Furst
, p. 1504 (1958)
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Reductive Coupling of Aryl Halides via C—H Activation of Indene
Zhang, Bo-Sheng,Yang, Ying-Hui,Wang, Fan,Gou, Xue-Ya,Wang, Xi-Cun,Liang, Yong-Min,Li, Yuke,Quan, Zheng-Jun
, p. 1573 - 1579 (2021/05/28)
This paper describes the first case of a reductive coupling reaction with indene, a non-heteroatom olefin used as a reducing agent. The scope of the substrate is wide. The homo-coupling, cross-coupling, and synthesis of 12 and 14-membered rings were realized. The control experiment, indene-product curve and density functional theory calculations showed that the η3-palladium indene intermediate was formed by C—H activation in the presence of cesium carbonate. We speculate that the final product was obtained through a Pd (IV) intermediate or aryl ligand exchange. In addition, we excluded the formation of palladium anion (Pd(0)?) intermediates.
Intermolecular coupling and intramolecular cyclization of aryl nitriles on Au(111)
Klaasen, Henning,Liu, Lacheng,Gao, Hong-Ying,Viergutz, Lena,Held, Philipp A.,Knecht, Tobias,Meng, Xiangzhi,B?rner, Melanie C.,Barton, Dennis,Amirjalayer, Saeed,Neugebauer, Johannes,Studer, Armido,Fuchs, Harald
supporting information, p. 11611 - 11614 (2019/10/02)
The on-surface dimerization reaction of an organic nitrile on Au(111) is reported. The formation of the product, which contains five newly formed σ-bonds and a diazapyrene core structure, was investigated and characterized by scanning tunneling microscopy. Experimental and computational studies of reference compounds support our findings.