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.
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 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
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.
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
A Binaphthyl-Based Scaffold for a Chiral Dirhodium(II) Biscarboxylate Ligand with α-Quaternary Carbon Centers
Chen, Po-An,Setthakarn, Krit,May, Jeremy A.
, p. 6155 - 6161 (2017)
A chiral dirhodium(II) paddlewheel complex has been synthesized from biscarboxylate ligands derived from BINOL, and the resulting complex has been used in enantioselective carbene/alkyne cascade reactions. The ligand design was guided by requirements of α
Single-component, low molecular weight organic supergelators based on chiral barbiturate scaffolds
Seidenkranz, Daniel T.,Langworthy, Kurt A.,Zakharov, Lev N.,Pluth, Michael D.
, p. 499 - 507 (2019)
We report here the first chiral barbiturate to act as a single-component LMOG capable of gelating a variety of chlorinated and aromatic solvents. Solution-based DOSY NMR experiments, solid-state VP-SEM, and X-ray crystallography techniques were used to ch
Enantioselective alkynylation of aromatic aldehydes catalyzed by new chiral amino alcohol-based ligands
Lu, Gui,Li, Xingshu,Zhou, Zhongyuan,Chan, Wing Lai,Chan, Albert S.C.
, p. 2147 - 2152 (2001)
A series of binaphthyl-derived amino alcohols were synthesized and used as catalytic ligands in the asymmetric alkynylation of aromatic aldehydes in the presence of a dialkylzinc reagent. The alkynylation of a variety of aromatic aldehydes gave the corres
Electrophilic trifluoromethylation of primary phosphines: Synthesis of a P -bis(trifluoromethyl) derivative of BINAP
Armanino, Nicolas,Koller, Raffael,Togni, Antonio
, p. 1771 - 1777 (2010)
The new chiral diphosphine ligand (R)-(2′-(bis(trifluoromethyl) phosphino)-1,1′-binaphthyl-2-yl)diphenylphosphine (2), which contains a bis(trifluoromethyl)phosphine group, was prepared in five steps from (R)-BINOL (5). As a key transformation, the unprecedented electrophilic double trifluoromethylation of the primary phosphine 8 was achieved using the hypervalent iodine trifluoromethylation reagent 1-trifluoromethyl-1,2- benziodoxol-3-(1H)-one (1), derived from o-iodobenzoic acid. The palladium dichloride complex of this ligand (10) shows the P(CF3)2 group with a high degree of pyramidalization at the P atom and a relatively short Pd?P bond (2.2230(4) A), both features being indicative of the strong s-character of the phosphorus lone pair.
Asymmetric Wittig reactions of chiral arsonium ylides. Part 3: Reversal of stereochemistry caused by metal cation in enantioselective olefination of 4-substituted cyclohexanones using a C2-symmetric chiral arsine
Dai, Wei-Min,Wu, Anxin,Wu, Huafeng
, p. 2187 - 2191 (2002)
A novel C2-symmetric chiral arsine was synthesized from (S)-(-)-1,1′-bi-2-naphthol in three steps. It was employed in the enantioselective olefination of 4-substituted cyclohexanones via a stabilized ylide formed in situ from the corresponding arsonium salt. Enantioselectivity up to 40% was obtained. Moreover, a reversal in the stereochemistry of the product was observed simply by changing the counter cation of the base from lithium to potassium.
Elaboration of a novel effective approach to enantiopure functionalised 2,2′-dialkyl-1,1′-binaphthyls by stereoconservative cross-couplings at positions 2 and 2′
Kasák, Peter,Putala, Martin
, p. 5279 - 5282 (2004)
The yield and the stereochemical outcome of methylations of 1,1 ′-binaphthyl-2,2′-dielectrophiles (ditriflate and diiodide) clearly depend on the reactivity of the organometallics used. It was found that only the Negishi reaction of
Application of a Ferrocene-Based Palladacycle Precatalyst to Enantioselective Aryl-Aryl Kumada Coupling
Arthurs, Ross A.,Hughes, David L.,Richards, Christopher J.
supporting information, (2022/02/21)
The palladium catalysed reaction of 1-iodo-2-methylnaphthalene and 2-methyl-1-naphthylmagnesium bromide gave quantitatively an (Sa)-configured cross-coupled product in 80 % e.e. using (R,Sp)-PPFA as a ligand. N,N-Dimethylaminomethylferrocene was cyclopalladated (Na2PdCl4, (S)?Ac?Phe?OH, 93 % e.e., as determined by 1H NMR as a result of self-induced non-equivalence), and the resulting (Sp)-configured dimeric palladacycle was employed as a precatalyst for this cross-coupling reaction (5 mol%). Addition to the palladacycle of diphenylphosphine and subsequent base-promoted bidentate ligand synthesis and palladium capture gave an in situ generated catalyst resulting in an (Sp)-configured product in up to 71 % e.e.
In Situ Generation of Ruthenium Carbonyl Phosphine Complexes as a Versatile Method for the Development of Enantioselective C?O Bond Arylation
Kondo, Hikaru,Kochi, Takuya,Kakiuchi, Fumitoshi
supporting information, p. 1737 - 1741 (2020/02/05)
We report here a method for in situ generation of various ruthenium carbonyl phosphine catalysts for arylation via cleavage of inert aromatic carbon–oxygen bonds. The use of catalyst systems consisting of [RuCl2(CO)(p-cymene)], CsF, styrene, an
