76041-86-6Relevant articles and documents
Boron–Nitrogen-Doped Nanographenes: A Synthetic Tale from Borazine Precursors
Dosso, Jacopo,Battisti, Tommaso,Ward, Benjamin D.,Demitri, Nicola,Hughes, Colan E.,Williams, P. Andrew,Harris, Kenneth D. M.,Bonifazi, Davide
supporting information, p. 6608 - 6621 (2020/04/22)
In this work, a comprehensive account of the authors’ synthetic efforts to prepare borazino-doped hexabenzocoronenes by using the Friedel–Crafts-type electrophilic aromatic substitution is reported. Hexafluoro-functionalized aryl borazines, bearing an ortho fluoride leaving group on each of the N- and B-aryl rings, was shown to lead to cascade-type electrophilic aromatic substitution events in the stepwise C?C bond formation, giving higher yields of borazinocoronenes than those obtained with borazine precursors bearing fluoride leaving groups at the ortho positions of the B-aryl substituents. By using this pathway, an unprecedented boroxadizine-doped PAH featuring a gulf-type periphery could be isolated, and its structure proven by single-crystal X-ray diffraction analysis. Mechanistic studies on the stepwise Friedel–Crafts-type cyclization suggest that the mechanism of the planarization reaction proceeds through extension of the π system. To appraise the doping effect of the boroxadizine unit on the optoelectronic properties of topology-equivalent molecular graphenes, the all-carbon and pyrylium PAH analogues, all featuring a gulf-type periphery, were also prepared. As already shown for the borazino-doped hexabenzocoronene, the replacement of the central benzene ring by its B3N2O congener widens the HOMO–LUMO gap and dramatically enhances the fluorescence quantum yield.
Directed Metalation-Suzuki-Miyaura Cross-Coupling Strategies: Regioselective Synthesis of Hydroxylated 1-Methyl-phenanthrenes
J?rgensen, K?re B.,Rantanen, Toni,D?rfler, Thilo,Snieckus, Victor
, p. 9410 - 9424 (2015/10/12)
A general, efficient, and regioselective synthesis of a series of hydroxylated 1-methylphenanthrenes 9 by a combined directed ortho metalation (DoM)-Suzuki-Miyaura cross-coupling-directed remote metalation (DreM) sequence is reported. Diversity to this methodology was achieved by a regioselective DoM rather than DreM reaction, affording more highly substituted phenanthrols (Table 2). Application of the turbo-Grignard reagent (i-PrMgCl·LiCl) in the Ni-catalyzed Corriu-Kumada reaction gave efficient decarbamoylation (Tables 3and 4). Additional features are the TMS protecting group and halo-induced ipso-desilylation tactics applied to the regioselective synthesis of phenanthrenes (Scheme 2).
Simple synthesis of amides and weinreb amides Using PPh3 or PolymerSupported PPh3 and Iodine
Kumar, Amit,Akula, Hari Kiran,Lakshman, Mahesh K.
experimental part, p. 2709 - 2715 (2010/08/05)
The combination of PPh3/I2 has been shown to be effective for the conversion of a range of carboxylic acids into secondary, tertiary, and Weinreb amides. Simplification of the procedure was possible with the use of polymer-supported PPh3/ I2. Weinreb amides produced with the use of polymer-supported PPh3 could be filtered through a short silica gel plug and used in further transformations. Thus, the use of polymer-supported PPh3 offers potential applicability to diversityoriented reactions. Formal total syntheses of apocynin and pratosine, as well as syntheses of anhydrolychorinone and hippadine, have been achieved through the use of this amide-forming method. An attempt has been made to gain insight into this reaction.
