5061-91-6Relevant academic research and scientific papers
Pd-Catalyzed Assembly of Fluoren-9-ones by Merging of C-H Activation and Difluorocarbene Transfer
Liu, Xiaobing,Sheng, Heyun,Zhou, Yao,Song, Qiuling
supporting information, p. 2543 - 2547 (2021/05/05)
We disclose a novel Pd-catalyzed assembly of fluoren-9-ones by merging of C-H activation and difluorocarbene transfer. ClCF2COONa served as a difluorocarbene precursor to be harnessed as a carbonyl source in this transformation. The current protocol enables us to afford fluoren-9-ones in high yields with excellent functional group compatibility, which also represents the first example of using difluorocarbene as a coupling partner in transition-metal-catalyzed C-H activation.
Nitrogen introduction of spirobifluorene to form α-, β-, γ-, and δ-aza-9,9′-spirobifluorenes: New bipolar system for efficient blue organic light-emitting diodes
Wu, Peng,Zhu, Jun,Zhang, Zhen,Dou, Dehai,Wang, Hedan,Wei, Bin,Wang, Zixing
, p. 185 - 191 (2018/04/17)
Four aza-9,9′-spirobifluorenes (aza-SBFs) with nitrogen atom at different positions of one fluorene moiety were synthesized to study the structure-properties relationships. α-Aza-SBF and β-aza-SBF possessed almost completely separated the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO), while γ-aza-SBF and δ-aza-SBF showed overlapped HOMO and LUMO orbitals. The aza-SBFs showed excellent bipolar features and good thermal stabilities than those of SBFs. The maximum current efficiencies (CE) of α-, β-, γ-, and δ-aza-SBF-based OLEDs were 28.8, 24.9, 25.5, and 27.2 cd/A, respectively. Compared to the SBF, all of four aza-SBFs showed better devices performances. The CE and power efficiency (PE) of OLED based on α-aza-SBF was 28.8 cd/A and 22.6 lm/W, while the SBF-based OLED was only 12.3 cd/A and 8.2 lm/W. The maximum external quantum efficiency of α-aza-SBF-based OLED was 15.4%, which was 2.5 times than that of the SBF-based one (6.6%) due to introduction of nitrogen improving electron transporting. Novel materials based on these components and their potential applications in organic electronics were expected due to their excellent bipolar features.
Aza-spirobifluorene derivative and preparation method thereof
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Paragraph 0087-0090; 0093, (2017/08/18)
The invention discloses an aza-spirobifluorene derivative. The aza-spirobifluorene derivative is characterized by having a structural formula as shown in the specification, wherein only one of X1, X2, X3 and X4 is a nitrogen atom, and the other three are carbon atoms; and R is an aromatic or heterocyclic aromatic ring containing 6-60 carbon atoms. The aza-spirobifluorene derivative disclosed by the invention can be used as an illuminant material; the aza-spirobifluorene derivative can be independently used as an illuminating layer or doped dye for illuminating or can be formed into an exciplex with the other materials for illuminating; the aza-spirobifluorene derivative also has a carrier transporting capacity; and a group has a hole transmitting capacity and an electron transmitting capacity. The aza-spirobifluorene derivative provided by the invention can be prepared into an excellent amorphous film according to vacuum evaporation or solution methods (spin coating, printing, and the like). The aza-spirobifluorene derivative also has higher thermal stability and photo-stability.
Intramolecular Acylation of Unactivated Pyridines or Arenes via Multiple C-H Functionalizations: Synthesis of All Four Azafluorenones and Fluorenones
Laha, Joydev K.,Jethava, Krupal P.,Patel, Sagarkumar,Patel, Ketul V.
, p. 76 - 85 (2017/04/26)
An unprecedented intramolecular acylation of unactivated pyridines via multiple C(sp3/sp2)-H functionalizations of a methyl, hydroxymethyl, or aldehyde group has been developed providing a general access to all four azafluorenones. The application of this protocol is further demonstrated to the synthesis of azafluorenone related fused nitrogen heterocycles and fluorenones. In addition, design and synthesis of a novel fluorene based organic emitter for potential use in organic light emitting devices (OLEDs) is also reported.
Practical radical cyclizations with arylboronic acids and trifluoroborates
Lockner, Jonathan W.,Dixon, Darryl D.,Risgaard, Rune,Baran, Phil S.
, p. 5628 - 5631 (2011/12/03)
Practical radical cyclizations using organoboronic acids and trifluoroborates take place in water, open to air, and in a scalable fashion employing catalytic silver nitrate and stoichiometric potassium persulfate. Both Pschorr-type cyclizations and tandem radical cyclization/trap cascades are described, illustrating the utility of these mild conditions for the generation of polycyclic scaffolds.
9-Hydroxyazafluorenes and their use in thrombin inhibitors
Stauffer, Kenneth J.,Williams, Peter D.,Selnick, Harold G.,Nantermet, Philippe G.,Newton, Christina L.,Homnick, Carl F.,Zrada, Matthew M.,Lewis, S. Dale,Lucas, Bobby J.,Krueger, Julie A.,Pietrak, Beth L.,Lyle, Elizabeth A.,Singh, Rominder,Miller-Stein, Cynthia,White, Rebecca B.,Wong, Bradley,Wallace, Audrey A.,Sitko, Gary R.,Cook, Jacquelyn J.,Holahan, Marie A.,Stranieri-Michener, Maria,Leonard, Yvonne M.,Lynch Jr., Joseph J.,McMasters, Daniel R.,Yan, Youwei
, p. 2282 - 2293 (2007/10/03)
Optimization of a previously reported thrombin inhibitor, 9-hydroxy-9-fluorenylcarbonyl-L-prolyl-trans-4-aminocyclohexylmethylamide (1), by replacing the aminocyclohexyl P1 group provided a new lead structure, 9-hydroxy-9-fluorenylcarbonyl-L-prolyl-2-aminomethyl-5-chlorobenzylamide (2), with improved potency (Ki = 0.49 nM for human thrombin, 2× APTT = 0.37 μM in human plasma) and pharmacokinetic properties (F = 39%, iv T1/2 = 13 h in dogs). An effective strategy for reducing plasma protein binding of 2 and improving efficacy in an in vivo thrombosis model in rats was to replace the lipophilic fluorenyl group in P3 with an azafluorenyl group. Systematic investigation of all possible azafluorenyl P3 isomers and azafluorenyl-N-oxide analogues of 2 led to the identification of an optimal compound, 3-aza-9-hydroxyfluoren-9(R)-ylcarbonyl-L-prolyl-2-aminomethyl-5- chlorobenzylamide (19b), with high potency (Ki = 0.40 nM, 2× APTT = 0.18 μM), excellent pharmacokinetic properties (F = 55%, T 1/2 = 14 h in dogs), and complete efficacy in the in vivo thrombosis model in rats (inhibition of FeCl3-induced vessel occlusions in six of six rats receiving an intravenous infusion of 10 μg/kg/min of 19b). The stereochemistry of the azafluorenyl group in 19b was determined by X-ray crystallographic analysis of its N-oxide derivative (23b) bound in the active site of human thrombin.
Synthesis and metallation of 2-(pyridyl)benzoic acids and ethyl 2-(pyridyl)benzoates: A new route to azafluorenones
Rebstock, Anne-Sophie,Mongin, Florence,Trécourt, Fran?ois,Quéguiner, Guy
, p. 4973 - 4977 (2007/10/03)
The ring deprotonation of 2-(2- and 4-pyridyl)benzoic acids using lithium dialkylamides in THF at rt, and the in situ cyclization afforded 4- and 2-azafluorenones, respectively. 1-Azafluorenone was obtained from ethyl 2-(3-pyridyl)benzoate using a similar protocol.
Thrombin inhibitors
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, (2008/06/13)
Compounds of the invention are useful in inhibiting thrombin and associated thrombotic occlusions having the following structure: or a pharmaceutically acceptable salt thereof, e.g. where R3 is —CH2NH2, —CH2CH2NH2, or —CH2NHC(O)OC(CH3)3.
Synthesis of azafluorenones using zeolites
Sreekumar,Rugmini,Padmakumar
, p. 2071 - 2075 (2007/10/03)
A convenient method for the synthesis of various azafluorenones (2a-f and 4a-d) by cyclization of substituted arylpyridines (1a-f and 3a-d) using zeolites are described.
SYNTHESES OF 2-AZAFLUORENONES FROM 3-SUBSTITUTED 4-ARYLPYRIDINES
Shiao, Min-Jen,Liu, Kang-Hsiuan,Lin, Pen-Yuan
, p. 507 - 518 (2007/10/02)
3-substituted 4-arylpyridines (5a-i) were synthesized in good yields by reaction of mixed copper, zinc aryl organometallics (2a-e) with 1-ethoxycarbonylpyridinium chlorides (1a-d) followed by o-chloranil oxidation under reflux in toluene.The arylpyridines (5a-i) are obtained predominantly.Having compounds (5a-i) in hand, a convenient method was developed for the synthesis of 2-azafluorenones (7a-f) by using cyclization of 4-arylpyridines (5a-i) with phosphoric acid.
