5628-11-5Relevant articles and documents
3D Coumarin Systems Based on [2.2]Paracyclophane: Synthesis, Spectroscopic Characterization, and Chiroptical Properties
Delcourt, Marie-Léonie,Reynaud, Corentin,Turcaud, Serge,Favereau, Ludovic,Crassous, Jeanne,Micouin, Laurent,Benedetti, Erica
, p. 888 - 899 (2019/01/24)
In this article, we report the preparation of a series of [2.2]paracyclophane-fused coumarin systems through a simple and general procedure involving a transition-metal-catalyzed cyclization of aryl alkynoates as the key step. We also highlight the influence of the [2.2]paracyclophane (pCp) motif and its "phane" interactions on the spectroscopic properties of the newly synthesized fluorophores, which emit in the blue-green region of the visible spectrum (?em up to 560 nm) and show extremely large Stokes shifts (up to 230 nm). Finally, we demonstrate that our straightforward approach can easily be used to access optically active planar chiral 3D coumarins. Compared to previously described fluorescent paracyclophanes and other organic dyes, our compact heteroaromatic derivatives show promising chiroptical properties, both in term of circular dichroism (gabs 8 × 10 -3) and circularly polarized luminescence (glum 5 × 10 -3), thus demonstrating a practical application of our synthetic method.
Development of Planar Chiral Iodoarenes Based on [2.2]Paracyclophane and Their Application in Catalytic Enantioselective Fluorination of β-Ketoesters
Wang, Yang,Yuan, Hang,Lu, Hongfei,Zheng, Wen-Hua
, p. 2555 - 2558 (2018/05/17)
The design and synthesis of novel planar chiral iodoarenes based on [2.2]paracyclophane is reported. A process of highly enantioselective oxidative fluorination of a β-ketoester with 3HF-Et3N as a nucleophilic fluoride source mediated by these new hypervalent iodine catalysts has been developed. This represents the first highly enantioselective reaction catalyzed by planar chiral hypervalent iodine.
Tuning the Reactivity of Peroxo Anhydrides for Aromatic C-H Bond Oxidation
Pilevar, Afsaneh,Hosseini, Abolfazl,?ekutor, Marina,Hausmann, Heike,Becker, Jonathan,Turke, Kevin,Schreiner, Peter R.
, p. 10070 - 10079 (2018/09/06)
Phenol moieties are key structural motifs in many areas of chemical research from polymers to pharmaceuticals. Herein, we report on the design and use of a structurally demanding cyclic peroxide (spiro[bicyclo[2.2.1]heptane-2,4′-[1,2]dioxolane]-3′,5′-dione, P4) for the direct hydroxylation of aromatic substrates. The new peroxide benefits from high thermal stability and can be synthesized from readily available starting materials. The aromatic C-H oxidation using P4 exhibits generally good yields (up to 96%) and appreciable regioselectivities.
Highly Efficient Kinetic Resolution of PHANOL by Chiral Phosphoric Acid Catalyzed Asymmetric Acylation
Mori, Keiji,Kishi, Hiroki,Akiyama, Takahiko
, p. 365 - 370 (2016/12/24)
We report herein a highly efficient kinetic resolution of PHANOL by chiral phosphoric acid catalyzed asymmetric acylation. PHANOL enantiomers were well differentiated by the chiral environment of chiral phosphoric acid, and both the corresponding monoester and PHANOL were obtained with excellent enantioselectivities (98% ee and 92% ee, respectively). Detailed examination of the substrates suggests that the presence of two hydroxy groups in PHANOL was critical for both reactivity and enantioselectivity.
Synthesis of bromo-substituted 4-hydroxy[2.2]paracyclophanes and [2.2]paracyclophane-4,7-quinones as versatile chiral building blocks
Atman, Natalia V.,Zhuravsky, Roman P.,Antonov, Dmitrii Yu,Sergeeva, Elena V.,Godovikov, Ivan A.,Starikova, Zoya A.,Vologzhanina, Anna V.
supporting information, p. 325 - 330 (2015/03/03)
Approaches to a number of bromo-substituted derivatives of 4-hydroxy[2.2]paracyclophane, including the regioselective mono- and dibromination of this phenol, were investigated. The applicability of the regioisomeric monobromo-substituted phenols for the synthesis of substituted [2.2]paracyclophane-4,7-quinones through a one-pot diazonium coupling/reduction/oxidation sequence was demonstrated. The compounds obtained possess various substitution patterns and could be used for the synthesis of a wide range of [2.2]paracyclophane derivatives by transformation of the bromine, hydroxy, and quinoid fragments.
Photochromism of novel chromenes constrained to be part of [2.2]paracyclophane: Remarkable 'phane' effects on the colored o-quinonoid intermediates
Moorthy, Jarugu Narasimha,Mandal, Susovan,Kumar, Amrit
, p. 82 - 88 (2013/02/25)
The photochemistry of rationally designed chromenes that are constrained to be part of [2.2]paracyclophane, i.e., CP-H and CP-OMe, was investigated to examine the effect of through-space delocalization in the cyclophane core (phane effect) on the photochr
Modular synthesis of planar-chiral para-substituted paracyclophanes by double Suzuki coupling
Cakici, Murat,Braese, Stefan
, p. 6132 - 6135 (2013/01/15)
The first synthesis of enantiomerically pure 4,7-paracyclophane ditriflate starting from a quinone was reported. Using this molecule, mono-or dicoupling with boronic acids delivered enantiomerically pure arylparacyclophanes.
Unprecedented directing group ability of cyclophanes in arene fluorinations with diaryliodonium salts
Graskemper, Joseph W.,Wang, Bijia,Qin, Linlin,Neumann, Kiel D.,Dimagno, Stephen G.
, p. 3158 - 3161 (2011/08/06)
For the first time it is shown that exceptionally electron-rich arene rings can be fluorinated exclusively during the reductive elimination reactions of diaryliodonium fluorides. The 5-methoxy[2.2]paracyclophan-4-yl directing group simultaneously reduces unproductive aryne chemistry and eliminates ligand exchange reactions by a combination of steric and electronic effects. Use of the cyclophane directing group permits an unprecedented degree of control in fluorination reactions of diaryliodonium salts.
Regiospecific reductive elimination from diaryliodonium salts
Wang, Bijia,Graskemper, Joseph W.,Qin, Linlin,DiMagno, Stephen G.
supporting information; experimental part, p. 4079 - 4083 (2010/08/07)
(Figure Presented) Out-of-plane steric bulk furnished by a cyclophane substituent on iodine(III) strongly destabilizes the transition state in the reductive elimination from diaryliodonium salts and leads to regiochemical control (dubbed SECURE), as is demonstrated by computational and experimental studies. This approach should be general for high-valent maingroup and transition metal ions. X=N3, OAc, PhO, CF3CH2O, SCN, PhS.
Improved synthesis of enantiopure 4-hydroxy[2.2]paracyclophane
Friedmann, Christian J.,Ay, Sefer,Braese, Stefan
experimental part, p. 4612 - 4614 (2010/09/09)
(Figure presented) 4-Hydroxy[2.2]paracyclophane is readily prepared via an improved synthetic protocol from unsubstituted [2.2]paracyclophane. The key step is a Dakin oxidation of 4-formyl[2.2]paracyclophane. This allows a rapid access to large quantities of the product and an easy synthesis of the enantiopure form.
