- Synthetic method 5 - bromo -1 and 2,3 - trimethoxy benzene
-
The synthesis method of 5 -bromo -1-2,3 -methoxy benzene comprises the following steps: S1, taking the vanillin as a starting raw material, and brominating 5 - bromo -2 - hydroxyl -3 -methoxybenzaldehyde through the hydroxyl group para-position. S2 is obt
- -
-
-
- Orthogonal Stability and Reactivity of Aryl Germanes Enables Rapid and Selective (Multi)Halogenations
-
While halogenation is of key importance in synthesis and radioimaging, the currently available repertoire is largely designed to introduce a single halogen per molecule. This report makes the selective introduction of several different halogens accessible. Showcased here is the privileged stability of nontoxic aryl germanes under harsh fluorination conditions (that allow selective fluorination in their presence), while displaying superior reactivity and functional-group tolerance in electrophilic iodinations and brominations, outcompeting silanes or boronic esters under rapid and additive-free conditions. Mechanistic experiments and computational studies suggest a concerted electrophilic aromatic substitution as the underlying mechanism.
- Deckers, Kristina,Fricke, Christoph,Schoenebeck, Franziska
-
supporting information
p. 18717 - 18722
(2020/08/25)
-
- New procedure for the highly regioselective aerobic bromination of aromatic compounds using copper-based nanocatalyst
-
A new procedure for the highly regioselective aerobic bromination of aromatic compounds in the presence of copper-based nanoparticles (CuO/ZnO nanocatalyst) under reflux condition is described. Mechanistic parameters are discussed and the plausible mechanism is proposed. Recyclability of the CuO/ZnO nanocatalyst has also been explored upon aerobic bromination of aromatic compounds.
- Albadi, Jalal,Jalali, Mehdi
-
p. 234 - 239
(2020/02/29)
-
- PROCESS FOR PRODUCTION OF OXIDATION REACTION PRODUCT OF AROMATIC COMPOUND
-
The present invention provides a process for producing an oxidation reaction product of an aromatic compound, having excellent environmental load reduction performance, cost reduction performance, etc. Provided is a process for producing an oxidation reaction product of a raw material aromatic compound by reacting the raw material aromatic compound with an oxidizing agent. The process further uses an electron donor-acceptor linked molecule. The process includes the step of: reacting the electron donor-acceptor linked molecule in an electron-transfer state, the oxidizing agent, and the raw material aromatic compound, thereby generating an oxidation reaction product resulting from oxidation of the raw material aromatic compound.
- -
-
Page/Page column 18
(2012/07/14)
-
- Predicting the structure of supramolecular dendrimers via the analysis of libraries of AB3 and constitutional isomeric AB2 biphenylpropyl ether self-assembling dendrons
-
The synthesis of 4′-hydroxy-4-biphenylpropionic, 3′,4′- dihydroxy-4-biphenylpropionic, 3′,5′-dihydroxy-4-biphenylpropionic, and 3′,4′,5′-trihydroxy-4-biphenylpropionic methyl esters via three efficient and modular strategies including one based on Ni-catalyzed borylation and sequential cross-coupling is reported. These building blocks were employed in a convergent iterative approach to the synthesis of one library of 3,4,5-trisubstituted and two libraries of constitutional isomeric 3,4- and 3,5-disubstituted biphenylpropyl ether dendrons. Structural and retrostructural analysis of supramolecular dendrimers revealed that biphenylpropyl ether dendrons self-assemble and self-organize into the same periodic lattices and quasi-periodic arrays observed in previously reported libraries, but with larger dimensions, different mechanisms of self-assembly, and improved solubility, thermal, acidic, and oxidative stability. The different mechanisms of self-assembly led to the discovery of two new supramolecular structures. The first represents a new banana-like lamellar crystal with a four layer repeat. The second is a giant vesicular sphere self-assembled from 770 dendrons that exhibits an ultrahigh molar mass of 1.73 × 106 g/mol. Thus, the enhanced size of the self-assembled structures constructed from biphenylpropyl ether dendrons permitted for the first time discrimination of various molecular mechanisms of spherical self-assembly and elaborated a continuum between small filled spheres and very large hollow spheres that is dictated by the primary structure of the dendron. The comparative analysis of libraries of biphenylpropyl ether dendrons with the previously reported libraries of benzyl-, phenylpropyl-, and biphenyl-4-methyl ether dendrons demonstrated biomimetic self-assembly wherein the primary structure of the dendron and to a lesser extent the structure of its repeat unit determines the supramolecular tertiary structure. A "nanoperiodic table" of self-assembling dendrons and supramolecular dendrimers that allows the prediction of the general features of tertiary structures from primary structures was elaborated.
- Rosen, Brad M.,Wilson, Daniela A.,Wilson, Christopher J.,Peterca, Mihai,Won, Betty C.,Huang, Chenghong,Lipski, Linda R.,Zeng, Xiangbing,Ungar, Goran,Heiney, Paul A.,Percec, Virgil
-
scheme or table
p. 17500 - 17521
(2010/03/25)
-
- PROCESSES FOR THE PREPARATION OF BIPHENYL COMPOUNDS
-
The invention concerns processes for the synthesis of a compound of the formula: wherein: R1 and R2 are each, independently, C1-C12 alkyl, CO2R3, OR4, R5(OR6), or C6-C18 aiyl; R3 -R6 are each, independently, C1-C12 alkyl or C6-C12 aryl; and n and m are each, independently, O or an integer from 1-5; said process comprising: — contacting a compound of the formula H0-R7-0H with BH3 and a compound of the formula in the presence of a nickel-containing catalyst to produce a first product, where R7 is a C2-C12 hydrocarbon group and X is a halogen, OMs or OTs; — contacting the first product in situ with a compound of the formula: in the presence of a nickel-containing catalyst to produce a compound of formula I, where Z is a halogen.
- -
-
Page/Page column 21; 22; 29; 30; 31
(2010/01/29)
-
- Investigation of the mechanism of action of pyrogallol-phloroglucinol transhydroxylase by using putative intermediates
-
Pyrogallol-phloroglucinol transhydroxylase from Pelobacter acidigallici, a molybdopterin-containing enzyme, catalyzes a key reaction in the anaerobic degradation of aromatic compounds. In vitro, the enzymatic reaction requires 1,2,3,5-tetrahydroxy-benzene as a cocatalyst and the trans-hydroxylation occurs without exchange with hydroxy groups from water. To test our previous proposal that the transfer of the hydroxy group occurs via 2,4,6,3′,4′, 5′-hexahydroxydiphenyl ether as an intermediate, we synthesized this compound and investigated its properties. We also describe the synthesis and characterization of 3,4,5,3′,4′,5′-hexahydroxydiphenyl ether. Both compounds could substitute for the cocatalyst in vitro. This indicates that the diphenyl ethers can intrude into the active site and initiate the catalytic cycle. Recently, the X-ray crystal structure of the transhydroxylase (TH) was published[16] and it supports the proposed mechanism of hydroxy-group transfer.
- Paizs, Csaba,Bartlewski-Hof, Ulrike,Rétey, János
-
p. 2805 - 2811
(2008/02/05)
-
- Exploring and expanding the structural diversity of self-assembling dendrons through combinations of AB, constitutional isomeric AB2, and AB3 biphenyl-4-methyl ether building blocks
-
General, efficient and inexpensive methods for the synthesis of dendritic building blocks methyl 3′,4′-dihydroxybiphenyl-4-carboxylate, 3′,5′-dihydroxybiphenyl-4-carboxylate, and methyl 3′,4′,5′-trihydroxybiphenyl-4-carboxylate were elaborated. In all syntheses the major step involved an inexpensive NiII-catalyzed Suzuki cross-coupling reaction. These three building blocks were employed together with methyl 4′-hydroxybiphenyl-4-carboxylate in a convergent iterative strategy to synthesize seven libraries containing up to three generations of 3′,4′-, 3′,5′-, and 3′,4′,5′-substituted biphenyl-4-methyl ether based amphiphilic dendrons. These dendrons self-assemble into supramolecular dendrimers that self-organize into periodic assemblies. Structural and retrostructural analysis of their assemblies demonstrated that these dendrons self-assemble into hollow and non-hollow supramolecular dendrimers exhibiting dimensions of up to twice those reported for architecturally related dendrons based on benzyl ether repeat units. These new dendrons expand the structural diversity and demonstrate the generality of the concept of self-assembling dendrons based on amphiphilic arylmethyl ethers.
- Percec, Virgil,Holerca, Marian N.,Nummelin, Sami,Morrison, John J.,Glodde, Martin,Smidrkal, Jan,Peterca, Mihai,Rosen, Brad M.,Uchida, Satoshi,Balagurusamy, Venkatachalapathy S. K.,Sienkowska, Monika J.,Heiney, Paul A.
-
p. 6216 - 6241
(2008/12/22)
-
- Non-steroidal ligands for the glucocorticoid receptor, compositions and uses thereof
-
The invention provides non-steroidal ligands for the glucocorticoid receptor, methods for making non-steroidal ligands of the glucocorticoid receptor, compositions of non-steroidal ligands of the glucocorticoid receptor and methods of using non-steroidal
- -
-
-
- Tetraphenylethene-derived columnar liquid crystals and their oxidative photocyclization
-
The synthesis of novel tetraphenylethenes 9a-f, 13, and 18a,b bearing ether, biphenyl, and 4-cyanobiphenyl moieties via a McMurry reaction and Suzuki coupling as key steps is described. Mesogenic properties of these compounds were studied by differential
- Schultz, Andreas,Laschat, Sabine,Diele, Siegmar,Nimtz, Manfred
-
p. 2829 - 2839
(2007/10/03)
-
- Ortho substituted chiral phosphines and phosphinites and their use in asymmetric catalytic reactions
-
3,3′-Substituted chiral biaryl phosphine and phosphinite ligands and metal complexes based on such chiral ligands useful in asymmetric catalysis are disclosed. The metal complexes are useful as catalysts in asymmetric reactions, such as, hydrogenation, hy
- -
-
-
- Synthesis and Tubulin-Binding Properties of Some AC- and ABC-Ring Analogues of Allocolchicine
-
Fourteen analogues of the powerful antimitotic agent allocolchicine (5) have been prepared and evaluated for their ability to prevent tubulin polymerization.The X-ray structure of one of the more active compounds, tricyc
- Banwell, Martin G.,Cameron, Jennifer M.,Corbett, Madeline,Dupuche, Joseph R.,Hamel, Ernest,et al.
-
p. 1967 - 1982
(2007/10/02)
-
- The Palladium-Mediated Cross Coupling of Bromotropolones with Organostannanes or Arylboronic Acids: Applications to the Synthesis of Natural Products and Natural Product Analogues
-
The bromotropolones (4), (5) and (10) undergo palladium-mediated cross coupling with a wide range of organostannanes to produce alkenyl-, alkyl- and aryl-substituted tropolones.The methodology has been applied to the synthesis of the monoterpenes β-dolabrin (11), β-thujaplicin (12), 4-isopropyl-7-methoxytropolone (13) and β-thujaplicinol (14).Cross coupling of bromotropolones (4), (5) and (10) with various aryltrimethylstannanes or arylboronic acids has permitted the preparation of the bicyclic colchicine analogues (30)-(43) which have been tested for tubulin-binding activity.The X-ray crystal structure of the most active of these systems, compound (38), is reported.
- Banwell, Martin G.,Cameron, Jennifer M.,Collis, Maree P.,Crisp, Geoffrey T.,Gable, Robert W.,'et al.
-
p. 705 - 728
(2007/10/02)
-
- THE INVENTION OF RADICAL REACTIONS. PART XVI. RADICAL DECARBOXYLATIVE BROMINATION AND IODINATION OF AROMATIC ACIDS
-
Thiohydroxamic esters of aromatic carboxylic acids undergo clean decarboxylative bromination or iodination on treatment with bromotrichloromethane, iodoform or diiodomethane in the presence of a radical initiator.
- Barton, Derek H.R.,Lacher, Brigitte,Zard, Samir Z.
-
p. 4321 - 4328
(2007/10/02)
-
- RADICAL DECARBOXYLATIVE BROMINATION OF AROMATIC ACIDS
-
Thiohydroxamic esters (mixed anhydrides) of aromatic and α,β-unsaturated carboxylic acids undergo clean decarboxylative bromination on treatment with bromotrichloromethane in the presence of a radical initiator.
- Barton, Derek H.R.,Lacher, Brigitte,Zard, Samir Z.
-
p. 5939 - 5942
(2007/10/02)
-
- Stereoselective Synthesis of an Analogue of Podophyllotoxin by an Intramolecular Diels-Alder Reaction
-
The dihydrobenzocyclobutene 90 having a 4-hydroxycrotonate unit attached via an ester linkage as an internal dienophile can be cyclized to a 3:1 mixture of the trans lactone 92 (an analogue of podophyllotoxin, 1) and the cis lactone 93.This stereoselective reaction proceeds via the intermediacy of the o-quinodimethane 91 which cyclizes from the endo transition state 91n in preference to the exo-one 91x, presumably because of stabilization of the former by secondary orbital overlap.This result provides evidence that a proposed general route to the synthesis of podophyllotoxin, 1, and its analogues via the internal cycloaddition of the o-quinodimethane 8 to 9n may prove successful.Several possible approaches to the synthesis of the trans-2-aryldihydrobenzocyclobutenol 4 are described.The benzyne 11 was prepared and underwent but no cycloadditions.Although the 2-bromobenzocyclobutenone 23 could be synthesized in an efficient manner, it proved impossible to convert it into 4 by means of the aryl organometallic reagents 22ab.The bromo epoxide 52 was prepared and subjected to metal-halogen exchange and Lewis acid catalyzed epoxide rearrangement in an attempt to prepare 4.The aldehyde 56 was obtained in this reaction, clearly indicating that the desired intermediate 54 had been formed but could not be trapped under these conditions.Two ring contraction routes to 4 are also described, both beginning with the 1-indanone 74 prepared in good yield from piperonal 14.The diol monomesylate 78, prepared from 74, suffered base-catalyzed E2 elimination rather than the desired rearrangement to 80.The diazo ketone 83 underwent Wolff rearrangement to give the desired ester 84, but only in 7percent yield.Two interesting transformations were observed in these ring contraction schemes, namely the formation of the oxathiole dioxide 77 on mesylation of the ketol 75 and the preparation of the diazirene 86 on photolysis of the diazo ketone 83 at long wavelengths.The ester 84 was then saponified to the acid 87 which was coupled with methyl 4-hydroxycrotonate, 5, to give 90.The assignment of the structures of the products of thermolysis of 90 was based on high field 1H NMR and analogy to the spectra of similar compounds in the literature.
- Jung, Michael E.,Lam, Patrick Yuk-Sun,Mansuri, Muzzamil M.,Speltz, Laurine M.
-
p. 1087 - 1105
(2007/10/02)
-
