126613-06-7Relevant articles and documents
Synthesis and properties of macrocyclic diazene switch with binaphthalene unit attached via acrylamide linkers
Kickova, Anna,Kerner, Lukas,Putala, Martin,Horvath, Branislav
, p. 101 - 109,9 (2013)
2,2′-Diiodo-1,1′-binaphthalene undergoes a tandem Heck reaction with methyl acrylate to afford methyl 2-(7H-dibenzo[c,g]fluoren-7-ylidene) acetate. As a consequence, the target macrocyclic diazene with binaphthalene unit attached via acrylamide linker was prepared by the stepwise building of acrylamide at a binaphthalene moiety, including the Doebner modification of the Knoevenagel condensation, and completed by oxidative macrocyclisation of aniline end-groups. Despite being an equimolar mixture of monomer and dimer, it exhibited remarkable changes in CD spectra due to reversible (E/Z) isomerisation of N=N diazene bonds upon irradiation at 365/465 nm. Although the dimer isomerises from (E) to (Z) isomer 7.4 times faster than the monomer, the latter's contribution to the change in ellipticity at 307 nm in the photostationary state is 2.4 times greater.
Large Scale Synthesis of Chiral (3 Z,5 Z)-2,7-Dihydro-1H-azepine-Derived Hamari Ligand for General Asymmetric Synthesis of Tailor-Made Amino Acids
Takahashi, Motohiro,Moriwaki, Hiroki,Miwa, Toshio,Hoang, Brittanie,Wang, Peng,Soloshonok, Vadim A.
, p. 619 - 628 (2019)
An advanced process for large scale (500 g) preparation of a (3Z,5Z)-2,7-dihydro-1H-azepine-derived chiral tridentate ligand (Hamari ligand), widely used for asymmetric synthesis of tailor-made α-amino acids via the corresponding glycine Schiff base Ni(II
Matching and mismatching effects of hybrid chiral biaxial bisphosphine ligands in enantioselective hydrogenation of ketoesters
Sun, Xianfeng,Li, Wei,Zhou, Le,Zhang, Xumu
, p. 7302 - 7305 (2009)
A study was conducted to demonstrate matching and mismatching of hybrid chiral biaxial bisphosphine ligands in enantioselective hydrogenation of ketoesters. A novel class of conformationally rigid Cn-TunePhos was developed by introducing a bridge with variable length to link the chiral atropisometic biaryl groups. The conformationally rigid Cn-TunePhos was introduce to investigate the synthesis and use of new chiral biophosphine ligands in asymmetric catalysis. A strategy was introduced for the synthesis of a pair of diastereoisomeric forms of ligands 1, 2, and an analogous ligand 3 to assess the effects of stereochemical matching and mismatching interactions upon the structural and catalytic properties of the corresponding ruthenium complexes. Their applications in highly efficient Ru-catalyzed asymmetric hydrogenation for the enantioselective synthesis of α- and β-hydroxy acid derivatives were also explored.
Synthesis of new chiral monodentate phosphines and their use in asymmetric hydrogenation
Junge, Kathrin,Oehme, Günther,Monsees, Axel,Riermeier, Thomas,Dingerdissen, Uwe,Beller, Matthias
, p. 4977 - 4980 (2002)
A general synthesis of chiral 4,5-dihydro-3H-dinaphthophosphepines 1a-g is described. The resulting ligands represent a new class of monodentate chiral phosphines. First applications of 1a-g in the rhodium-catalyzed asymmetric hydrogenation of unsaturated
Synthesis of a novel chiral binaphthyl phospholane and its application in the highly enantioselective hydrogenation of enamides.
Xiao,Zhang,Zhang
, p. 1679 - 1681 (1999)
[formula: see text] A new chiral phosphine, (R,R)-1,2-bis[(R)-4,5-dihydro-3H-dinaphtho[2,1- c:1',2'-e]phosphepino]benzene [abbreviated as (R,R)-binaphane] was prepared on the basis of a practical route from a readily accessible enantiomerically pure binap
Chiral silanediols in anion-binding catalysis
Schafer, Andrew G.,Wieting, Joshua M.,Fisher, Thomas J.,Mattson, Anita E.
, p. 11321 - 11324 (2013)
A perfect pair: Silanediols are effective catalysts for the addition of silyl ketene acetals to N-acylisoquinolinium ions. Importantly, this is the first example of a silanediol plausibly participating in anion-binding catalysis, a relatively new direction in the field of hydrogen-bond-donor catalysis. The chiral, enantiopure C2-symmetric silanediol 1 catalyzes enantioselective transformations. Copyright
Catalytic, asymmetric aza-Baylis-Hillman reaction of N-sulfonated imines with 2-cyclohexen-1-one and 2-cyclopenten-1-one in the presence of a chiral phosphine Lewis base
Shi, Min,Li, Chao-Qun
, p. 1385 - 1391 (2005)
In the aza-Baylis-Hillman reaction of N-sulfonated imines with 2-cyclohexen-1-one or 2-cyclopenten-1-one, we found that by using (R)-2′-dimethylphosphanyl-[1,1′]binaphthalenyl-2-ol LB1 as a chiral phosphine Lewis base, the corresponding Baylis-Hillman adducts 2 or 3 can be obtained in good yields and moderate enantiomeric excess. The structure of this chiral phosphine Lewis base on chiral induction in this reaction has also been discussed.
A scalable synthesis of (R)-3,5-dihydro-4H-dinaphth[2,1-c:1′2′ -e]azepine
Ikunaka, Masaya,Maruoka, Keiji,Okuda, Yoshiaki,Ooi, Takashi
, p. 644 - 648 (2003)
Environmentally benign scalable procedures are developed to supply enantiomerically pure (R)-3,5-dihydro-4H-dinaphth[2,1-c:1′2′ -e]azepine 1 as its hydrogen oxalate salt in a five-step overall yield of 41%, which consist of the following: (1) his O-triflation of (R)-1,1′ -bi-2-naphthol 8 [(CF3SO2)2O, pyridine, PhMe; quantitative yield]; (2) Kumada's cross-coupling [MeMgI, NiCl2(dppp), tert-BuOMe; 96% yield]; (3) radical bromination [N-bromosuccinimide, 2,2′-azobisisobutyronitrile, cyclohexane; 54% yield]; (4) cyclization [allylamine, Et3N, THF, 86%]; (5) N-deallylation [1,3-dimethylbarbituric acid, Pd(OAc)2, Ph3P, PhMe] followed by crystalline salt formation with oxalic acid (overall 92% yield).
Development of a new class of C1-symmetric bisphosphine ligands for rhodium-catalyzed asymmetric hydrogenation
Dai, Qian,Li, Wei,Zhang, Xumu
, p. 6943 - 6948 (2008)
A new class of C1-symmetric bisphosphine ligands with three hindered quadrants have been obtained through facile synthesis from chiral BINOL derivatives. Their rhodium complexes have exhibited high enantioselectivities (up to 98% ee) in the asy
Supramolecular Polymerization of [5]Helicenes. Consequences of Self-Assembly on Configurational Stability
Valera, Jorge S.,Gómez, Rafael,Sánchez, Luis
, p. 2020 - 2023 (2018)
The supramolecular polymerization of [5]helicenes 1 and 2 is investigated. The self-assembly of these helicenes proceeds by the operation of H-bonding interactions with a negligible participation of π-stacking. The enantiopurity of the sample has a dramatic effect on the supramolecular polymerization mechanism since it reverts the isodesmic mechanism for the racemic mixture to a cooperative one for the enantioenriched sample. Noticeably, the formation of supramolecular polymers efficiently increases the configurational stability of 1,14-unsubstituted [5]helicenes.