21987-62-2Relevant articles and documents
Two protocols for the conversion of biphenol to binaphthol: Synthesis of diospyrol
Thasana, Nopporn,Pisutjaroenpong, Somchai,Ruchirawat, Somsak
, p. 1080 - 1084 (2006)
The application of directed orthometallation (DoM), Fries rearrangement and transmetallation followed by allylation and cyclization is reported for the conversion of biphenol to binaphthol as a means for the synthesis of diospyrol. Furthermore, the same t
Dynamic axial chirality control of a carboxybiphenol through acid-base interaction
Morioka, Kohei,Tamagawa, Norio,Maeda, Katsuhiro,Yashima, Eiji
, p. 110 - 111 (2006)
A novel, fluorescent 2,2′-biphenol bearing two carboxyl and two ethynyl groups was found to be sensitive to the chirality of the chiral diamines, thus showing an induced circular dichroism due to an excess single-handed, axially twisted conformation. Copyright
Antenna biphenols: Development of extended wavelength chiroptical reporters
Bentley, Keith W.,Joyce, Leo A.,Sherer, Edward C.,Sheng, Huaming,Wolf, Christian,Welch, Christopher J.
, p. 1185 - 1191 (2016)
Molecular hosts capable of chiroptical sensing of complexed guest molecules offer an attractive alternative to conventional methods for the analysis of the absolute configuration and enantiopurity. Sensors based on the Pfeiffer effect rely on complexation
Docking Site Modulation of Isostructural Covalent Organic Frameworks for CO2 Fixation
Chen, Long,Li, Yusen,Xing, Guolong,Yang, Fan,Zhang, Ting,Zhao, Ziqiang
, (2020)
Three isostructural covalent organic frameworks (COFs) with either methoxyl, hydroxyl, or both groups on the channel wall, are synthesized and served as metal-free heterogeneous catalysts for chemical fixation of CO2. Among them, the COF decora
Relay Catalysis to Synthesize β-Substituted Enones: Organocatalytic Substitution of Vinylogous Esters and Amides with Organoboronates
Sundstrom, Sasha,Nguyen, Thien S.,May, Jeremy A.
supporting information, p. 1355 - 1359 (2020/02/13)
Organocatalysis was shown to facilitate conjugate additions to vinylogous esters and amides for the first time. Subsequent elimination of a β-alcohol or amine provided π-conjugated β-substituted enones. Remarkably, nucleophile addition to the electron-rich vinylogous substrates is more rapid than classical enones, forming monosubstituted products. A doubly organocatalytic (organic diol and methyl aniline) conjugate addition synthesized the products directly from alkynyl ketones. Both of these catalytic transformations are orthogonal to transition metal catalysis, allowing for good yields, easily accessible or commercially available reagents, high selectivity, reagent recovery and recyclability, facile scalability, and exceptional functional group tolerance.
Syntheses of Molybdenum(VI) Imido Alkylidene Complexes That Contain a Bidentate Dithiolate Ligand
Tafazolian, Hosein,Tsay, Charlene,Schrock, Richard R.,Müller, Peter
, p. 4024 - 4030 (2018/10/31)
Zn(DCTC) (DCTC = 3,6-dichlorodithiacatecholate) reacts with Mo(NAd)(CHCMe2Ph)Cl2(PPh2Me) (Ad = 1-adamantyl) to give Mo(NAd)(CHCMe2Ph)(DCTC)(PPh2Me). The reactions between Zn(DCTC) and Mo(NAd)(CH-t-Bu)(OTf)2(dme) or Mo(NAr)(CHCMe2Ph)(OTf)2(dme) (Ar = 2,6-i-Pr2C6H3; OTf = triflate; dme = 1,2-dimethoxyethane) produce [Mo(NAd)(CH-t-Bu)(DCTC)]2 and [Mo(NAr)(CHCMe2Ph)(DCTC)]2, respectively. Complexes that contain a 3,3′,5,5′-tetrasubstituted dithiabiphenolate were prepared in a reaction between Mo(NAr)(CHCMe2Ph)(Me2pyr)2 (Me2pyr = 2,5-dimethylpyrrolide) and the 3,3′,5,5′-tetrasubstituted dithiabiphenols, (3,3′,5,5′-tetrachlorodithiabiphenol (H2Cl4S2), 3,3′,5,5′-tetrabromodithiabiphenol (H2Br4S2), and 3,3′,5,5′-tetra-t-Bu-dithiabiphenol (H2Bu4S2)). The isolated complexes include Mo(NAr)(CHCMe2Ph)(Cl4S2)(pyridine), Mo(NAr)(CHCMe2Ph)(Br4S2)(pyridine), Mo(NAr)(CHCMe2Ph)(Bu4S2)(PMe3), and [Mo(NAr)(CHCMe2Ph)(Cl4S2)]2. Only the dithiabiphenolate derivatives (in the presence of B(C6F5)3) show activity for the metathesis of 1-decene, and although that reaction is limited by a sensitivity of the alkylidene complexes to ethylene, as suggested by the reaction between ethylene and Mo(NAr)(CHCMe2Ph)(Bu4S2) to give the ethylene complex, Mo(NAr)(C2H4)(Bu4S2). Mo(NAr)(C2H4)(Bu4S2) was unstable with respect to loss of ethylene and formation of an ethylene-free dimer. Mo(NAd)(CHCMe2Ph)(DCTC)(PPh2Me), [Mo(NAr)(CHCMe2Ph)(DCTC)]2, and [Mo(NAr)(CHCMe2Ph)(Cl4S2)]2 were characterized crystallographically.
Flexible Zirconium MOFs as Bromine-Nanocontainers for Bromination Reactions under Ambient Conditions
Pang, Jiandong,Yuan, Shuai,Du, Dongying,Lollar, Christina,Zhang, Liangliang,Wu, Mingyan,Yuan, Daqiang,Zhou, Hong-Cai,Hong, Maochun
supporting information, p. 14622 - 14626 (2017/10/23)
A series of flexible MOFs (PCN-605, PCN-606, and PCN-700) are synthesized and applied to reversible bromine encapsulation and release. The chemical stability of these Zr-MOFs ensures the framework's integrity during the bromine adsorption, while the framework's flexibility allows for structural adaptation upon bromine uptake to afford stronger host–guest interactions and therefore higher bromine adsorption capacities. The flexible MOFs act as bromine-nanocontainers which elongate the storage time of volatile halides under ambient conditions. Furthermore, the bromine pre-adsorbed flexible MOFs can be used as generic bromine sources for bromination reactions giving improved yields and selectivities under ambient conditions when compared with liquid bromine.
Control the Structure of Zr-Tetracarboxylate Frameworks through Steric Tuning
Pang, Jiandong,Yuan, Shuai,Qin, Junsheng,Liu, Caiping,Lollar, Christina,Wu, Mingyan,Yuan, Daqiang,Zhou, Hong-Cai,Hong, Maochun
supporting information, p. 16939 - 16945 (2017/11/30)
Ligands with flexible conformations add to the structural diversity of metal-organic frameworks but, at the same time, pose a challenge to structural design and prediction. Representative examples include Zr-tetracarboxylate-based MOFs, which afford assorted structures for a wide range of applications, but also complicate the structural control. Herein, we systematically studied the formation mechanism of a series of (4,8)-connected Zr-tetracarboxylate-based MOFs by altering the substituents on different positions of the organic linkers. Different ligand rotamers give rise to three types of structures with flu, scu, and csq topologies. A combination of experiment and molecular simulation indicate that the steric hindrance of the substituents at different positions dictates the resulting MOF structures. Additionally, the controllable formation of different structures was successfully implemented by a combination of linkers with different steric effects at specific positions.
Biphenol-based phosphoramidite ligands for the enantioselective copper-catalyzed conjugate addition of diethylzinc
Alexakis, Alexandre,Polet, Damien,Rosset, Stephane,March, Sebastien
, p. 5660 - 5667 (2007/10/03)
Phosphoramidite ligands, based on ortho-substituted biphenols and a chiral amine, induce high enantioselectivities (ee's up to 99%) in the copper-catalyzed conjugate addition of dialkylzinc reagents to a variety of Michael acceptors. Particularly, the best reported ee's were obtained for acyclic nitroolefins.
Construction of an ortho-phenol polymer
Xu, Ming-Hua,Lin, Zhi-Ming,Pu, Lin
, p. 6235 - 6238 (2007/10/03)
Synthesis and study of an ortho-phenol polymer, a highly functionalized polyphenylene, have been conducted. A dibromo ortho-biphenol monomer was synthesized and its homocoupling in the presence of Ni(1,5-cyclooctadiene)2 followed by hydrolysis led to the formation of an ortho-phenol polymer. This polymer was soluble in common organic solvents. It was characterized by gel permeation chromatography, UV-vis, IR, 1H and 13C NMR spectroscopic methods. The use of this polymer in the Lewis acid-catalyzed reaction of phenylacetylene with benzaldehyde in the presence of diethylzinc was studied. It was found that the polymer when treated with 1/4 equiv. (relative to the phenol unit of the polymer) of Ti(OiPr)4 generated a much more active Lewis acid catalyst than when treated with excess Ti(OiPr)4. This indicates that different types of catalytic sites in the polymer have been produced under these conditions.
