- Contribution to the study of the mechanism of directed remote-metalation. Evidence for the intermediacy of a geminal dimetallo dialkoxide C(OM) 2 (M = Li, K), first doubly charged director of ortho metalation
-
(Chemical Equation Presented) The mechanism of the metalation of 2-biphenyl carboxylic acid (1) with the Lochmann-Schlosser superbase was determined by deuteriolysis. Both ortho (C3) and remote (C2′) positions are metalated. The C2-metalated species 2 cyclizes instantaneously. Under suitable conditions, the doubly charged geminal dimetallo dialkoxide group C(OM)2 4 directs metalation in the adjacent position (C1), affording a stable 1-metallo-9H-fluorene-9,9-dimetallo dialkoxide 5 that can be trapped by diverse electrophiles to give 1-substituted 9H-fluoren-9-ones 7 and 9 after acidic workup.
- Tilly, David,Samanta, Subhendu S.,De, Asish,Castanet, Anne-Sophie,Mortier, Jacques
-
-
Read Online
- Combined directed ortho metalation - Intramolecular Friedel-Crafts connections. Regiospecific route to 1-substituted fluoren-9-ones
-
ortho-Substituted-2-biphenyl carboxylic acids of the type 3a-j were prepared by the tandem metalation sequence from 2-biphenyl carboxylic acid 1 with sec-butyllithium in THF at -78°C followed by quenching with electrophiles. The carboxylic acids 3a-f were converted into 1-substituted fluorenones 4a-f upon treatment with methanesulfonic acid.
- Tilly, David,Samanta, Subhendu S,Faigl, Ferenc,Mortier, Jacques
-
-
Read Online
- Preparation method of 1-bromofluorenone
-
The invention discloses a preparation method of 1-bromo fluorenone, and belongs to the field of organic chemical synthesis. The method is realized by the following steps of: reacting 2-bromophenyl acetonitrile serving as an initial raw material with nitrobenzene to synthesize 3-(2-bromophenyl)-5-benzoisoxazole; reducing 3-(2-bromophenyl)-5-benzoisoxazole by iron powder to obtain 2-aminobenzene-2'-bromobenzophenone, and finally performing intramolecular cyclization to synthesize 1-bromofluorenone with the content of 99.5% (HPLC) or above and the total yield of 76% or above. The synthesis methodis low in production cost and suitable for industrial production, and 1-bromofluorenone can be used in the fields of organic photoelectric materials, biomedicines and dyes.
- -
-
Paragraph 0010; 0020; 0023-0024 ;0027-0028; 0031
(2021/03/30)
-
- C1-Linked Spirobifluorene Dimers: Pure Hydrocarbon Hosts for High-Performance Blue Phosphorescent OLEDs
-
Reported here are C1-linked spiro-bifluorene dimers. A comprehensive study is carried out to analyze the electronic properties of these highly twisted structures. This work shows that the C1-position enables the design of pure hydrocarbon materials, with a high triplet energy, for hosting blue phosphors in efficient phosphorescent OLEDs (PhOLEDs). To date, this work describes the highest performance of blue PhOLEDs ever reported for pure hydrocarbons (external quantum efficiency of ca. 23 %), thus highlighting the potential of the C1-spirobifluorene scaffold in organic electronics.
- Sicard, Lambert J.,Li, Hong-Cheng,Wang, Qiang,Liu, Xiang-Yang,Jeannin, Olivier,Rault-Berthelot, Jo?lle,Liao, Liang-Sheng,Jiang, Zuo-Quan,Poriel, Cyril
-
supporting information
p. 3848 - 3853
(2019/02/24)
-
- Synthesis of Fluorenones from Benzaldehydes and Aryl Iodides: Dual C-H Functionalizations Using a Transient Directing Group
-
The first synthesis of substituted fluorenones directly from benzaldehydes and aryl iodides via a Pd(II)-catalyzed C(sp2)-H functionalization cascade is reported. Featuring anthranilic acid as an inexpensive transient directing group, the process is compatible with a variety of benzaldehydes and aryl iodides. A three-step synthesis of the antiviral drug Tilorone was completed in an excellent overall yield (40%), demonstrating the utility of this method.
- Chen, Xiao-Yang,Ozturk, Seyma,Sorensen, Erik J.
-
supporting information
p. 1140 - 1143
(2017/03/14)
-
- The expedient and regioselective metalation of unprotected biphenyl-2-, -3-, and -4-carboxylic acids
-
Unprotected biphenyl-2-carboxylic acid can be cleanly metalated with sec-butyllithium at the position adjacent to the carboxylate and can then be subjected to site-selective electrophilic substitution. The remote C2′-position is attacked by the superbasic
- Tilly, David,Samanta, Subhendu S.,Castanet, Anne-Sophie,De, Asish,Mortier, Jacques
-
p. 174 - 182
(2007/10/03)
-
- Practical synthesis of an open geodesic polyarene with a fullerene-type 6:6-double bond at the center: Diindeno[1,2,3,4-defg;l′,2′,3′,4′-mnop]chrysene
-
Diindeno[1,2,3,4-defg;l′,2′,3′,4′-mnop]chrysene (1), the smallest possible alkene-centered C60 substructure with a curved π-system, is obtained in 25-35% yield by flash vacuum pyrolysis of the twisted 1,1′-dibromobifluorenylidene (2) on a 100 mg scale at 1050 °C. At 1200 °C, the bowl-shaped hydrocarbon I rearranges to the planar isomer diindeno[5,6,7,1-defg;5′,6′,7′,1′-Imnop]chrysene (14) by a double 5/6 ring-expansion/ring-contraction. X-ray crystallography establishes that the central carbon atoms of 1 are nearly 80% as pyramidalized as the carbon atoms of C60 (POAV angles = 9.0° and 11.6° for 1 and C60, respectively). A four-step synthesis has been developed to prepare the pyrolysis precursor (2) as a mixture of (E)- and (Z)-isomers in 39% overall yield from commercially available 9-fluorenone-l-carboxylic acid (10).
- Bronstein, Hindy E.,Choi, Neil,Scott, Lawrence T.
-
p. 8870 - 8875
(2007/10/03)
-
- Intramolecular Addition of Aryl Radicals to Carbon-Nitrogen Double Bonds
-
Cyclisation of radicals 6a,b is highly regioselective towards a 5-exo process; 6-endo ring closure is a minor route and their ratio depends on the substituents.No ring expansion of the five-membered radical intermediates 7a,b was observed.Radicals 27a,b give rise to 5-exo cyclisation regiospecifically.A competitive 1,5-hydrogen shift leading to imidoyl radicals was noticed.An analogous behaviour is also exhibited by vinyl radicals when allowed to add to carbon-nitrogen double bonds.
- Gioanola, Milena,Leardini, Rino,Nanni, Daniele,Pareschi, Patrizia,Zanardi, Giuseppe
-
p. 2039 - 2054
(2007/10/02)
-