100780-04-9Relevant articles and documents
Synthesis and Chiral Recognition of Optically Active Crown Ethers incorporating a 4,4'-Biphenanthryl Moiety as the Chiral Centre
Yamamoto, Koji,Noda, Koji,Okamoto, Yoshio
, p. 1065 - 1066 (1985)
Two chiral crown ethers (+)-S-(4) and (-)-(R,R)-(5) with a 4,4'-biphenanthryl moiety as the chiral centre have been prepared, and their chiral recognition properties were examined to show that (+)-(S)-(4) has a high enantiomer selectivity for 2-aminotetralin and 1,2-diphenylethylamine.
Absolute configuration of 3,3'-Dihydroxy-4,4' -biphenanthryl as determined by the stereochemistry of cyclic diester formation with 1,1'-Binaphthyl-2,2'-dicarboxylic acid
Koike,Hattori,Miyano
, p. 1899 - 1900 (1994)
Condensation of racemic 3,3'-dihydroxy-4,4'-biphenanthryl [(±)-2] with (R)-1,1'binaphthyl-2,2'-dicarboxylic acid dichloride (5) allows cyclization of only (-)-2 to give the 12-membered cyclic diester (7), the absolute configuration of which can be assigned (R,R) from steric reasons. Thus, absolute stereochemistry of (-)-2 is determined to be (R).
Pyrene-Fused [7]Helicenes Connected Via Hexagonal and Heptagonal Rings: Stereospecific Synthesis and Chiroptical Properties
Braunschweig, Holger,Radacki, Krzysztof,Ravat, Prince,Swain, Asim Kumar
, p. 993 - 1000 (2022/01/27)
In this manuscript, we portrayed a stereospecific synthesis of C2- and C1-symmetric pyrene-fused [7]helicene compounds 1 and 2, respectively. Compounds 1 and 2 were synthesized via a one-pot Suzuki coupling–C–H activation and two-step Suzuki coupling–Scholl reaction, respectively, with complete retention of configuration. The synthesized molecules differ in the fusing mode of [7]helicene units with pyrene via six- and seven-membered rings for 1 and 2, respectively. There was a significant difference in the functional properties and enantiomerization barrier of both compounds because of their distinct molecular symmetry as well as fusing mode to pyrene moiety. The heptagon-containing molecule 2 showed remarkable photophysical and chiroptical properties with commendable configurational stability compared to 1 and pristine [7]helicene as well as its [5]helicene congener.
The Trityl Cation Embedded into a [7]Helicene-Like Backbone: Preparation and Application as a Lewis Acid Catalyst
Gross, Benjamin M.,Oestreich, Martin
, p. 2512 - 2516 (2021/03/22)
The synthesis of a helically chiral carbenium ion is reported. The new motif is essentially a trityl cation embedded into a [7]helicene-like framework. The key step in its preparation establishes the π-extended fluorenone system in one step by an unprecedented palladium-catalyzed carbonylative annulation of a 4,4′-biphenanthryl-3,3′-diyl precursor. The racemic form of the new carbon Lewis acid was found to catalyze a representative set of reactions typically promoted by the trityl cation.
Enantioselective oxidative-coupling of polycyclic phenols
Takizawa, Shinobu,Kodera, Junpei,Yoshida, Yasushi,Sako, Makoto,Breukers, Stefanie,Enders, Dieter,Sasai, Hiroaki
, p. 1786 - 1793 (2014/03/21)
Enantioselective oxidative-coupling of polycyclic phenols, such as 2-anthracenol, 9- or 3-phenanthrol, and 5-chrysenol was established by using vanadium(V/IV) catalysis under air or O2 as a co-oxidant. In the vanadium catalyzed reaction, the co
Benzylic-type couplings provide an important asymmetric entry to functionalized, non-racemic helicenes
Terrasson, Vincent,Roy, Myriam,Moutard, Stephane,Lafontaine, Marie-Pier,Pepe, Gerard,Felix, Guy,Gingras, Marc
, p. 32412 - 32414 (2014/08/18)
Benzylic-type couplings are key reactions to make non-racemic helicenes. Their simplicity contributes to a short, efficient, and scalable asymmetric route to functionalized [7]helicenes. It widens the scope and uses of enantiopure helicenes, which are unequivocally needed for new chiroptical-electronic materials. A mechanistic proposal featuring an electrocyclization is based on experiments, X-ray crystallography and calculations. the Partner Organisations 2014.
Stereospecific synthesis of hetero[7]helicenes by Pd-catalyzed double N-arylation and intramolecular O-arylation
Nakano, Koji,Hidehira, Yuko,Takahashi, Keita,Hiyama, Tamejiro,Nozaki, Kyoko
, p. 7136 - 7138 (2007/10/03)
(Chemical Equation Presented) Enantioenriched aza- and oxa[7]helicenes are synthesized from an enantiopure biphenanthryldiol in a highly stereoselective manner. An N-phenylaza[7]helicene is prepared by a palladium-catalyzed double N-arylation of aniline w
New Axially Chiral Sulfur Compounds: Synthesis and Conformational Stability of Enantiopure 4,4'-Biphenanthrene-3,3'-dithiol and Related Atropisomeric Derivatives
Dore, Antonio,Fabbri, Davide,Gladiali, Serafino
, p. 779 - 788 (2007/10/02)
Enantiopure (R)- and (S)-4,4'-biphenanthrene-3,3'-dithiol 1a has been prepared for the first time through a synthetic procedure involving in the key stop a stereoconservative Newman-Kwart thermorearrangement of the bis-N,N-dimethylthiocarbamoyl ester of (R)- and (S)-biphenanthrol 2b, respectively.The atropisomeric conformations of 1a are not, interconverted even at temperatures as high as 285 deg C, whereas the related biphenanthrothiophene 3 is completely racemized in a few minutes at 250 deg C.The axially chiral backbone of 1a has been incorporated in a set of novel C2 symmetry sulfur reagents suitable for a variety of stereoselective reactions.
