- Methylene Bridging Effect on the Structures, Lewis Acidities and Optical Properties of Semi-planar Triarylboranes
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Three synthetic methods towards semi-planar triarylboranes with two aryl rings connected by a methylene bridge have been developed. The fine-tuning of their stereoelectronic properties and Lewis acidities was achieved by introducing fluorine, methyl, methoxy, n-butyl and phenyl groups either at their exocyclic or bridged aryl rings. X-ray diffraction analysis and quantum-chemical calculations provided quantitative information on the structural distortion experienced by the near planar hydro-boraanthracene skeleton during the association with Lewis bases such as NH3 and F?. Though the methylene bridge between the ortho-positions of two aryl rings of triarylboranes decreased the Gibbs free energies of complexation with small Lewis bases by less than 5 kJ mol?1 relative to the classical Lewis acid BAr3, the steric shielding of the CH2 bridge is sufficient to avoid the formation of Lewis adducts with larger Lewis bases such as triarylphosphines. A newly synthesized spirocyclic amino-borane with a long intramolecular B?N bond that could be dissociated under thermal process, UV-irradiation, or acidic conditions might be a potential candidate in Lewis pairs catalysis.
- Doan, Thu-Hong,Chardon, Aurélien,Osi, Arnaud,Mahaut, Damien,Tumanov, Nikolay,Wouters, Johan,Champagne, Beno?t,Berionni, Guillaume
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supporting information
p. 1736 - 1743
(2020/12/11)
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- Process for the production of bretylium tosylate
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A method of producing pharmaceutical grade bretylium tosylate comprising low amounts of mutagenic impurities. The method comprises forming bretylium tosylate having a purity of less than 99.5% and purifying the bretylium tosylate by: i) forming a slurry of the bretylium tosylate with a mixture of acetone and ethyl acetate; ii) filtering the slurry to obtain purified bretylium tosylate. The bretylium tosylate so produced has a purity of at least 99.5%, and suitably comprises less than 0.5 ppm of the potentially mutagenic impurity ethyl p-toluenesulfonate. The bretylium tosylate so produced also suitably comprises less than 0.5 ppm of the potentially mutagenic impurity 2-bromobenzylbromide.
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Page/Page column 7; 8
(2020/11/23)
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- Complex Boron-Containing Molecules through a 1,2-Metalate Rearrangement/anti-SN2′ Elimination/Cycloaddition Reaction Sequence
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The three-component coupling of benzylamines, boronic esters, and 4-phenyl-3 H -1,2,4-triazole-3,5(4 H)-dione (PTAD) is reported. The boronate complex formed from an ortho -lithiated benzylamine and a boronic ester undergoes a stereospecific 1,2-metalate rearrangement/ anti -S N 2′ elimination in the presence of an N-activator to provide a dearomatized tertiary boronic ester. Interception of this dearomatized intermediate with a dienophile leads to stereopredictable cycloaddition reactions to generate highly complex three-dimensional boron-containing molecular structures. When enantioenriched α-methyl-substituted benzylamines are employed, the corresponding cycloaddition adducts are formed with excellent enantiospecificities.
- Tillin, Chloe,Bigler, Raphael,Calo-Lapido, Renata,Collins, Beatrice S.L.,Noble, Adam,Aggarwal, Varinder K.
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supporting information
p. 449 - 453
(2019/02/26)
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- Enantiospecific Synthesis of ortho-Substituted 1,1-Diarylalkanes by a 1,2-Metalate Rearrangement/anti-SN2′ Elimination/Rearomatizing Allylic Suzuki–Miyaura Reaction Sequence
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The one-pot sequential coupling of benzylamines, boronic esters, and aryl iodides has been investigated. In the presence of an N-activator, the boronate complex formed from an ortho-lithiated benzylamine and a boronic ester undergoes stereospecific 1,2-metalate rearrangement/anti-SN2′ elimination to form a dearomatized tertiary boronic ester. Treatment with an aryl iodide under palladium catalysis leads to rearomatizing γ-selective allylic Suzuki–Miyaura cross-coupling to generate 1,1-diarylalkanes. When enantioenriched α-substituted benzylamines are employed, the corresponding 1,1-diarylalkanes are formed with high stereospecificity.
- Rubial, Belén,Collins, Beatrice S. L.,Bigler, Raphael,Aichhorn, Stefan,Noble, Adam,Aggarwal, Varinder K.
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supporting information
p. 1366 - 1370
(2019/01/04)
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- Hypercoordinated organotin(IV) compounds containing C,O- and C,N- chelating ligands: Synthesis, characterisation, DFT studies and polymerization behaviour
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A series of 2-methoxymethyl tetraorganotins [2-(MeOCH2)C6H4]SnR3 (21: R = Ph; 22: R = n-Bu; 23: R = Me), diorganotin chlorides [2-(MeOCH2)C6H4]R2SnCl (24: R = Ph; 25a, 25b: R = n-Bu), monoorganotin dichlorides [2-(MeOCH2)C6H4]RSnCl2 (26: R = Ph; 27: R = n-Bu; 28: R = Me) and the tin trichloride [2-(MeOCH2)C6H4]SnCl3 (29) were successfully prepared from the reaction of the organolithium, [2-(MeOCH2)C6H4]Li, and the appropriate chlorostannane. Similarly, a series of dimethylamino stannanes including the tetraorganotin [2-(Me2NCH2)C6H4]SnPh3 (30), the diorganotin halides [2-(Me2NCH2)C6H4]Ph2SnX (34: X = Cl; 35: X = Br), dichlorides [2-(Me2NCH2)C6H4]RSnCl2 (38: R = Ph; 39: R = n-Bu; 40: R = Me) and the tribromide [2-(Me2NCH2)C6H4]SnBr3 (37) were prepared by reaction of the appropriate organochlorostannane and the organolithium [2-(Me2NCH2)C6H4]Li followed by selective halogenations in the case of 34–37. 2-Methoxymethyl and dimethylamino diorganotin dichlorides (27, 28 and 39, 40) were hydrogenated with LiAlH4 to produce new 2-methoxymethyl [2-(MeOCH2)C6H4]RSnH2 (41: R = n-Bu; 42: R = Me) and dimethylamino [2-(Me2NCH2)C6H4]RSnH2 (44: R = n-Bu; 45: R = Me) dihydrides. X-ray structure determination of 30 revealed a nearly tetrahedral stannane, while structural analysis of 24, 29 and 40 display distorted trigonal bipyramidal geometry at Sn with Cl trans to the datively coordinated heteroatom. A selection of DFT methods were assessed for accuracy in predicting the solid-state geometries of the hypercoordinate Sn complexes. Catalytic dehydrocoupling of C,O- (41) and C,N- (44) diorganotin dihydrides was explored using Wilkinson's catalyst at RT leading to the recovery of modest molecular weight polymers (52: Mw = 3.03 × 104 Da, PDI = 1.4, 53: Mw = 3.1 × 104 Da, PDI = 1.86). The new rigid polymers were isolated in moderate (52: 65%) and low yields (53: 18%) and were found to be amorphous by DSC.
- Khan, Aman,Pau, Jeffrey,Loungxay, Julie,Magobenny, Timbila,Wylie, R. Stephen,Lough, Alan J.,Foucher, Daniel
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supporting information
(2019/09/12)
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- Visible-Light-Mediated α-Oxygenation of 3-(N,N-Dimethylaminomethyl)-Indoles to Aldehydes
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The visible-light-mediated oxygenation of 3-N,N-(dimethylaminomethyl)-indoles bearing various substituents afforded a series of 3-carbaindole derivatives. Herein we describe the reaction scope, a plausible mechanism and a practical application of this transformation in the formal synthesis of (–)-vincorine is described as well.
- Stanek, Filip,Paw?owski, Robert,Mlynarski, Jacek,Stodulski, Maciej
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supporting information
p. 6624 - 6628
(2018/10/20)
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- Lewis Acid-Catalyzed Reductive Amination of Aldehydes and Ketones with N,N-Dimethylformamide as Dimethylamino Source, Reductant and Solvent
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A practical zinc acetate dihydrate-catalyzed reductive amination of various carbonyl compounds with N,N-dimethylformamide (DMF) as dimethylamino (Me2N) source, reductant and solvent has been developed. This reaction shows broad substrate scope,
- Yang, Luo,Lin, Jie,Kang, Lei,Zhou, Wang,Ma, Da-You
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supporting information
p. 485 - 490
(2018/01/15)
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- Graphene-enhanced platinum-catalysed hydrosilylation of amides and chalcones: A sustainable strategy allocated with in situ heterogenization and multitask application of H2PtCl6
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We describe a new sustainable strategy for the comprehensive utilization of a platinum catalyst in different organic transformations, in which an organosilicon/graphene-supported platinum catalyst prepared from a simple hydrosilylation-type reduction could be further used in the 1,4-hydrosilylation of chalcones. The rationally designed and in situ formed Pt@G@Si nanocatalyst is demonstrated to be highly effective in the 1,4-hydrosilylation of α,β-unsaturated enones, allowing for the facile synthesis of a variety of otherwise inaccessible substituted silyl enolates. In addition, with the aid of platinum catalyst residue and TBAF, the one-pot downstream Michael addition of substituted silyl enolates to alkyl acrylates is also reported in this work.
- Li, Ning,Dong, Xiao-Yun,Zhang, Jing-Lei,Yang, Ke-Fang,Zheng, Zhan-Jiang,Zhang, Wei-Qiang,Gao, Zi-Wei,Xu, Li-Wen
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p. 50729 - 50738
(2017/11/10)
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- Enantiospecific Synthesis of ortho-Substituted Benzylic Boronic Esters by a 1,2-Metalate Rearrangement/1,3-Borotropic Shift Sequence
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Coupling reactions between benzylamines and boronic esters have been investigated. ortho-Lithiated benzylamines react with boronic esters and a N-activator to afford ortho-substituted benzylic boronic esters with formal 1,1′-benzylidene insertion into the C-B bond. The reaction occurs by a SN2′ elimination and 1,2-metalate rearrangement of the N-activated boronate complex to afford a dearomatized intermediate, which undergoes a Lewis-acid catalyzed 1,3-borotropic shift to afford the boronic ester products in high yield and with excellent enantiospecificity. The use of enantioenriched α-substituted benzylamines gave the corresponding secondary boronic esters with high ee.
- Aichhorn, Stefan,Bigler, Raphael,Myers, Eddie L.,Aggarwal, Varinder K.
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supporting information
p. 9519 - 9522
(2017/07/25)
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- Long-range bonding/nonbonding interactions: A donor-acceptor resonance studied by dynamic NMR
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Long-range bonding interactions were evaluated using variable-temperature NMR spectroscopy and suitable 2′-CH2X-substituted phenylpyridines (X = Me, NMe2, OMe, F). It was found that the arylpyridyl rotational barriers were lower when electronegative atoms were bound to the α carbon of the 2′ moiety. This effect was ascribed to a stabilizing interaction in the transition state due to the lone pair of the heterocyclic nitrogen with the α carbon. Computational support for this hypothesis came from CCSD(T)/6-31+G(d) calculations. Steric effects of the X moiety were ruled out by comparison of the rotational barriers of analogous biphenyls.
- Ruzziconi, Renzo,Lepri, Susan,Buonerba, Federica,Schlosser, Manfred,Mancinelli, Michele,Ranieri, Silvia,Prati, Luca,Mazzanti, Andrea
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supporting information
p. 2740 - 2743
(2015/06/16)
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- IMPROVED PROCESS FOR THE REDUCTIVE AMINATION AND SELECTIVE HYDROGENATION OF SUBSTRATES CONTAINING A SELECTED HALOGEN
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Disclosed is a process for performing a chemical reaction selected from reductive amination and hydrogenation of a first functional group in an organic feed substrate, which feed substrate comprises at least one further functional group containing a halogen atom, wherein the halogen atom is selected from the list consisting of chlorine, bromine, iodine, and combinations thereof, in the presence of hydrogen and a heterogeneous catalyst comprising at least one metal from the list of Pd, Rh, and Ru, together with at least a second metal from the list consisting of Ag, Ni, Co, Sn, Cu and Au. The process is preferably applied for the reductive amination of 2-chloro- benzaldehyde to form 2-chloro-benzyldimethylamine, as an intermediate in the production of agrochemically active compounds and microbiocides of the methoximinophenylglyoxylic ester series. Further disclosed is a composition rich in 2-chloro-benzyldimethylamine, further comprising an amount of 2- chloro-benzyl alcohol and being low in chlorotoluene isomers.
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Page/Page column 35
(2015/03/28)
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- GAMMA-DIKETONES AS WNT/BETA -CATENIN SIGNALING PATHWAY ACTIVATORS
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The present disclosure provides γ-diketones or analogs thereof, that activate Wnt/β-catenin signaling and thus treat or prevent diseases related to signal transduction, such as osteoporosis and osteoarthropathy; osteogenesis imperfecta, bone defects, bone fractures, periodontal disease, otosclerosis, wound healing, craniofacial defects, oncolytic bone disease, traumatic brain injuries or spine injuries, brain atrophy/neurological disorders related to the differentiation and development of the central nervous system, including Parkinson's disease, strokes, ischemic cerebral disease, epilepsy, Alzheimer's disease, depression, bipolar disorder, schizophrenia; otic disorders like cochlear hair cell loss; eye diseases such as age related macular degeneration, diabetic macular edema or retinitis pigmentosa and diseases related to differentiation and growth of stem cell, such as hair loss, hematopoiesis related diseases and tissue regeneration related diseases.
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Paragraph 1735; 1736
(2014/09/03)
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- Superelectrophilic intermediates in nitrogen-directed aromatic borylation
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The first examples of borylation under conditions of borenium ion generation from hydrogen-bridged boron cations are described. The observable H-bridged cations are generated by hydride abstraction from N,N-dimethylamine boranes Ar(CH2)nNMe2BH3 using Ph3C+ (C6F5)4B - (TrTPFPB) as the hydride acceptor. In the presence of excess TrTPFPB, the hydrogen-bridged cations undergo internal borylation to afford cyclic amine borane derivatives with n = 1-3. The products are formed as the corresponding cyclic borenium ions according to reductive quenching experiments and 11B and 1H NMR spectroscopy in the case with Ar = C6H5 and n = 1. The same cyclic borenium cation is also formed from the substrate with Ar = o-C6H4SiMe3 via desilylation, but the analogous system with Ar = o-C6H 4CMe3 affords a unique cyclization product that retains the tert-butyl substituent. An ortho-deuterated substrate undergoes cyclization with a product-determining isotope effect of kH/kD 2.8. Potential cationic intermediates have been evaluated using B3LYP/6-31G* methods. The computations indicate that internal borylation from 14a occurs via a C-H insertion transition state that is accessible from either the borenium π complex or from a Wheland intermediate having nearly identical energy. The Ar = o-C6H4SiMe3 example strongly favors formation of the Wheland intermediate, and desilylation occurs via internal SiMe3 migration from carbon to one of the hydrides attached to boron.
- De Vries, Timothy S.,Prokofjevs, Aleksandrs,Harvey, Jeremy N.,Vedejs, Edwin
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supporting information; experimental part
p. 14679 - 14687
(2010/01/06)
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- 1-(2-Naphthyl)-1H-pyrazole-5-carboxylamides as potent factor Xa inhibitors. Part 2: A survey of P4 motifs
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A variety of P4 motifs have been examined to increase the binding affinity and in vitro anticoagulant potency of our biphenyl 1-(2-naphthyl)-1H-pyrazole-5- carboxylamide-based fXa inhibitors. Highly potent 2-naphthyl-P1 fXa inhibitors (Ki≤2 nM) with improved in vitro anticoagulant activity (2×TG≤1 μM) and respectable pharmacokinetic properties have been discovered.
- Jia, Zhaozhong J.,Wu, Yanhong,Huang, Wenrong,Zhang, Penglie,Clizbe, Lane A.,Goldman, Erick A.,Sinha, Uma,Arfsten, Ann E.,Edwards, Susan T.,Alphonso, Merlyn,Hutchaleelaha, Athiwat,Scarborough, Robert M.,Zhu, Bing-Yan
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p. 1221 - 1227
(2007/10/03)
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- Substituted 2-dialkylaminoalkylbiphenyl derivatives
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Substituted 2-dialkylaminoalkylbiphenyl derivatives, processes for their preparation, pharmaceutical compositions comprising these compounds and methods using these compounds for the preparation of medicaments and for the treatment of diseases.
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- Aminoisoquinolines and aminotheinopyridine derivatives and their use as anti-inflammatory agents
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PCT No. PCT/SE97/00589 Sec. 371 Date Aug. 19, 1997 Sec. 102(e) Date Aug. 19, 1997 PCT Filed Apr. 9, 1997 PCT Pub. No. WO97/38977 PCT Pub. Date Oct. 23, 1997Compounds of formula I wherein R, R1, R2, and R3 and A are as defined herein, together with pharmaceutically acceptable salts, enantiomers or tautomers are useful as pharmaceuticals, particularly in the treatment of inflammatory disease.
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- Optical resolution and configurational stability of selenoxides stabilized by intramolecular coordination
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2-((Dimethylamino)methyl)phenyl alkyl (or aryl) selenoxides, configurationally stabilized by intramolecular coordination of an amino group to the selenium atom, were optically resolved into their enantiomeric isomers by means of high-performance liquid chromatography using an optically active column packed with amylosecarbamate derivative/silica gel. This is the first example of the isolation of optically pure selenoxides without bulky substituents and also the first isolation of optically pure alkyl aryl selenoxides. The absolute configuration of the (-)-isomers could be assigned to be the S-form by comparison of their specific rotations, circular dichroism spectra, and behavior on the optically active column with those of the sulfur analogue, prepared by Andersen's method. Racemization of the optically active selenoxides was accelerated not only in acidic solution but also in basic media. This result indicates there are two different mechanisms for their racemization in acidic and basic media. The stabilization energy of the selenoxides by the intramolecular coordination of an amino group to the selenium atom was estimated to be ca. 3 kcal mol-1 on the basis of variable-temperature 1H NMR measurements.
- Shimizu, Toshio,Enomoto, Masao,Taka, Hideo,Kamigata, Nobumasa
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p. 8242 - 8247
(2007/10/03)
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- Intramolecularly coordinated arylmagnesium compounds: effects on the Schlenk equilibrium
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A series of phenylmagnesium bromides (1, 3-8) with ortho-substituents capable of forming intramolecular coordinative bonds along with the corresponding diarylmagnesium compounds (1a, 3a-6a, 8a) have been synthesized.The thermodynamic parameters ΔHs and ΔSs for the Schlenk equilibria (2 ArMgBr Ar2Mg + MgBr2) have been determined by variable temperature NMR spectroscopy.Crystal structures were obtained of 5,6,8,9-tetrahydrodibenzoxamagnesecin (2a) and bis(2,6-di(methoxymethyl)phenyl)magnesium (4a).The extent of intramolecular coordination in these compounds as determined in the solid state, is used in the discussion of the influence of substituents on the Schlenk equilibrium parameters.Unusual penta- or hexa-coordination is encountered and explained as a consequence of intramolecular coordination.
- Markies, Peter R.,Altink, Rinke M.,Villena, Alan,Akkerman, Otto S.,Bickelhaupt, Friedrich,et al.
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p. 289 - 312
(2007/10/02)
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- Potential Antidepressants. Synthesis of 6,11-Dihydrodibenzothiepin-11-yl 4-(Dimethylaminomethyl)phenyl Ketone and of Some Related Compounds
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Reactions of dibenzothiepin-11(6H)-one (4) with 2-, 3- and 4-(dimethylaminomethyl)phenylmagnesium bromide afforded the tertiary alcohols 5a,b,c.The aldehydes 7 and 8 gave similarly the secondary alcohols 9a,b,c and 10c.Numerous attempts to prepare the corresponding ketones, especially by oxidation of 9a,b,c and 10c were unsuccessful.Only the oxidation of 9c with tetrabutylammonium chromate in chloroform afforded the desired ketone 16.Its formation was accompanied by an important side reaction consisting in a cleavage of the "retro-ene-reaction" type leading to compound 11 and the aldehyde 13c which reacted with the chloroform present to give the alcohol 17.Compounds 5a,b,c, 9a,b,c and 16 were tested as potential antidepressants but with the exception of some effects in the test of potentiation of yohimbine toxicity in mice, they proved inactive in this line.
- Metysova, Jirina,Protiva, Miroslav
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p. 1325 - 1330
(2007/10/02)
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