2041-27-2Relevant academic research and scientific papers
Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone
Bracher, Franz,Jourjine, Ilya A. P.,Krau?, Jürgen,Zeisel, Lukas
supporting information, p. 2668 - 2679 (2021/11/30)
Highly substituted fluorenones are readily prepared in mostly fair to good yields via metal- and additive-free TBHP-promoted cross-dehydrogenative coupling (CDC) of readily accessible N-methyl-2-(aminomethyl)biphenyls and 2-(aminomethyl)biphenyls. This methodology is compatible with numerous functional groups (methoxy, cyano, nitro, chloro, and SEM and TBS-protective groups for phenols) and was further utilized in the first total synthesis of the natural product nobilone.
Spirocentric Compounds and Polymers Thereof
-
, (2019/09/20)
The present invention is directed to novel functionalized spirocentric compounds and polymers thereof that produce hyper-rigid cross-linked membranes.
The synthesis, chain-packing simulation and long-term gas permeability of highly selective spirobifluorene-based polymers of intrinsic microporosity
Bezzu, C. Grazia,Carta, Mariolino,Ferrari, Maria-Chiara,Jansen, Johannes C.,Monteleone, Marcello,Esposito, Elisa,Fuoco, Alessio,Hart, Kyle,Liyana-Arachchi,Colina, Coray M.,McKeown, Neil B.
, p. 10507 - 10514 (2018/06/13)
Membranes composed of Polymers of Intrinsic Microporosity (SBF-PIMs) have potential for commercial gas separation. Here we report a combined simulation and experimental study to investigate the effect on polymer microporosity and gas permeability by placing simple substituents such as methyl, t-butyl and fused benzo groups onto PIMs derived from spirobifluorene (PIM-SBFs). It is shown that methyl or t-butyl substituents both cause a large increase in gas permeabilities with four methyl groups enhancing the concentration of ultramicropores (a greater concentration of larger, less selective, micropores (>1.0 nm). Long-term ageing studies (>3.5 years) demonstrate the potential of PIM-SBFs as high-performance membrane materials for gas separations. In particular, the data for the PIM derived from tetramethyl substituted SBF reaches the proposed 2015 Robeson upper bound for O2/N2 and, hence, hold promise for the oxygen or nitrogen enrichment of air. Mixed gas permeation measurements for CO2/CH4 of the aged PIM-SBFs also demonstrate their potential for natural gas or biogas upgrading.
Palladium-catalyzed synthesis of fluoreones from bis(2-bromophenyl)methanols
Gao, Qian,Xu, Senmiao
, p. 208 - 212 (2018/01/12)
A palladium-catalyzed synthesis method of fluorenones has been developed. A variety of bis(2-bromophenyl)methanols could undergo the reaction smoothly in the presence of Pd(OAc)2, affording a series of fluorenones in moderate to good yields (two steps). Mechanistic studies reveal that the reaction might be triggered by oxidation of alcohol followed by intramolecular reductive coupling.
Palladium-catalyzed cyclocarbonylation of cyclic diaryliodoniums: Synthesis of fluorenones
Liu, Li,Qiang, Jian,Bai, Shuhua,Li, Yang,Miao, Chunbao,Li, Jian
, (2017/09/30)
An efficient approach to the synthesis of fluorenones via the palladium-catalyzed cyclocarbonylation of cyclic diaryliodoniums was developed. Our route enables facile access to fluorenones with various substituents in modest to high yields.
Metal free TBHP-promoted intramolecular carbonylation of arenes: Via radical cross-dehydrogenative coupling: Synthesis of indenoquinolinones, 4-azafluorenones and fluorenones
Mishra, Kalpana,Pandey, Ashok Kumar,Singh, Jay Bahadur,Singh, Radhey M.
, p. 6328 - 6336 (2016/07/11)
A metal-free, TBHP-promoted economical route is developed via the sp2 C-H bond functionalization strategy for the synthesis of indenoquinolinones, 4-azafluorenones and fluorenones. Reactions provided excellent yield of the products under mild conditions. We have successfully synthesized 11H-indeno[1,2-b]quinolin-11-one, an antibacterial agent, in excellent yields.
Domino Oxidative [Pd]-Catalysis: One-Pot Synthesis of Fluorenones Starting from Simple Benzylamines and Iodo Arenes
Ravi Kumar, Devarapalli,Satyanarayana, Gedu
supporting information, p. 5894 - 5897 (2015/12/11)
A domino [Pd]-catalysis for the efficient synthesis of fluorenones is presented. The overall reaction proceeds through the formation of a five membered Pd(II)-cycle via a highly regioselective ortho C(sp2)-H activation(s) of simple benzylamine that combines with external iodo arenes to give ortho arylated products. Significantly, the reaction further activates the C(sp3)-H and C(sp2)-H (intramolecular oxidative Heck coupling) bonds to give tricyclic imine systems. Then the usual water workup affords the fused tricyclic ketones (fluorenones). Remarkably, this one-pot operation enabled the effective construction of two C-C to three C-C bonds
Intramolecular Friedel-Crafts Acylation Reaction Promoted by 1,1,1,3,3,3-Hexafluoro-2-propanol
Motiwala, Hashim F.,Vekariya, Rakesh H.,Aubé, Jeffrey
, p. 5484 - 5487 (2015/11/18)
Simple dissolution of an arylalkyl acid chloride in 1,1,1,3,3,3-hexafluoro-2-propanol promotes an intramolecular Friedel-Crafts acylation without additional catalysts or reagents. This reaction is operationally trivial in both execution and product isolation (only requiring concentration followed by purification) and accommodates a broad range of substrates. Preliminary studies that bear upon potential reaction mechanisms are reported.
Cross dehydrogenative coupling via base-promoted homolytic aromatic substitution (BHAS): Synthesis of fluorenones and xanthones
Wertz, Sebastian,Leifert, Dirk,Studer, Armido
supporting information, p. 928 - 931 (2013/03/28)
Cross dehydrogenative coupling reactions occurring via base-promoted homolytic aromatic substitutions (BHASs) are reported. Fluorenones and xanthones are readily prepared via CDC starting with readily available ortho-formyl biphenyls and ortho-formyl biphenylethers, respectively. The commercially available and cheap tBuOOH is used as an oxidant. Initiation of the radical chain reaction is best achieved with small amounts of FeCp2 (0.1 or 1 mol %).
Regioselective ortho-arylation and alkenylation of N-alkyl benzamides with boronic acids via ruthenium-catalyzed C-H bond activation: An easy route to fluorenones synthesis
Chinnagolla, Ravi Kiran,Jeganmohan, Masilamani
supporting information, p. 5246 - 5249,4 (2020/09/02)
A highly regioselective ruthenium-catalyzed ortho-arylation of substituted N-alkyl benzamides with aromatic boronic acids in the presence of [{RuCl 2(p-cymene)}2], AgSbF6, and Ag2O is described. Further, ortho-arylated N-alkyl benzamides were converted into fluorenones in the presence of trifluoroacetic anhydride and HCl.
