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1.
E.Peter Kündig Candice Botuha Gilles Lemercier Patrick Romanens Lionel Saudan Sylvie Thibault 《Helvetica chimica acta》2004,87(3):561-579
Three different routes were probed for the synthesis of enantiomerically enriched 2‐(1‐aminoethyl)phenols and their methyl ethers. The first route centers on diastereoselective nucleophile addition to chiral imines. The second route has as key steps the enantioselective reduction of a ketone followed by nucleophilic substitution, and the third route involves a diastereoselective imine reduction. The efficiency of the approach depends on the substrate substitution pattern. All three methods work well for the parent compound 2‐(1‐aminoethyl)phenol ( 1 ) but the third route is the most efficient, providing the compound with >96% enantiomer excess in three steps with an overall yield of 71%. Conversely, for the ortho‐methyl analogue 2 , the first method is best. For the t‐Bu‐substituted analogue 3 , only moderate enantiomeric enrichment was achieved. 相似文献
2.
Florence Popowycz Sandrine Gerber‐Lemaire Catherine Schütz Pierre Vogel 《Helvetica chimica acta》2004,87(4):800-810
New 2‐(aminomethyl)‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol derivatives were synthesized from (5S)‐5‐[(trityloxy)methyl]pyrrolidin‐2‐one ( 6 ) (Schemes 1 and 2) and their inhibitory activities toward 25 glycosidases assayed (Table). The influence of the configuration of the pyrrolidine ring on glycosidase inhibition was evaluated. (2R,3R,4S,5R)‐2‐[(benzylamino)methyl]‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol ((+)‐ 21 ) was found to be a good and selective inhibitor of α‐mannosidase from jack bean (Ki=1.2 μM ) and from almond (Ki=1.0 μM ). Selectivity was lost for the non‐benzylated derivative (2R,3R,4S,5R)‐2‐(aminomethyl)‐5‐(hydroxymethyl)pyrrolidine‐3,4‐diol ((+)‐ 22 ) which inhibited α‐galactosidases, β‐galactosidases, β‐glucosidases, and α‐N‐acetylgalactosaminidase as well. 相似文献
3.
The reaction of glycolic acid 1 with some β‐aminoalcohols 2–8 without solvent, with temperature and time controlled, led to the syntheses of2‐hydroxy‐N‐(2′‐hydroxyalkyl)acetamides 9–15. All compounds studied in this work were characterized by 1H, 13C, and 15N NMR, infrared, and mass spectroscopy. The structure of compound 13 was established by a single‐crystal X‐ray diffraction study. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 153–158, 1999 相似文献
4.
2‐(2‐Amino‐3,4,5,6‐tetrafluorophenyl)benzoxazole ( 2 ) absorbs in long wavelength band (λabsmax = 346 nm in methanol) and in the normal wavelength band (λabsmax = 285.5 nm), and emits blue fluorescence. The emission intensity is highly affected by the solvent polarity and is large in a polar solvent such as methanol. 2‐(2‐Pentafluorobenzamido‐3,4,5,6‐ tetrafluorophenyl)benzoxazole ( 5 ) emits green fluorescence along with the short wavelength emission around 380 nm and their relative intensity depends on the solvent polarity. Green fluorescence is enhanced in nonpolar solvents such as chloroform and toluene, resulting in the considerably large Stokes shift. 相似文献
5.
Starting from the readily available benzylamine hydrochloride a series of 2‐(2‐alkylthio‐1‐benzyl‐5imida‐zolyl)‐1,3,4‐oxadiazoles were prepared. 相似文献
6.
7.
3‐Arylsydnone‐4‐carbohydroximic acid chlorides ( 1 ) could react with sodium azide to produce the corresponding 3‐arylsydnone‐4‐carbazidoximes ( 2 ), but not 1‐hydroxytetrazoles 3 . Treatment of 3‐arylsydnone‐4‐carbazidoximes ( 2 ) with acid chlorides such as acetyl chloride ( 4a ), propionyl chloride ( 4b ) and benzoyl chloride ( 4c ) in the presence of excess triethylamine generated the derivatives of the azidoximes 5 . To obtain the desired tetrazoles, the azidoximes 2 should first cyclize directly with acetyl chloride ( 4a ) or propionyl chloride ( 4b ) to afford the acetyl or propionyl derivatives 6 . The cyclized tetrazole derivatives 6 underwent deacylation upon heating in ethanol to give 1‐hydroxy‐5‐(3‐arylsydnon‐4‐yl)tetrazoles ( 3 ). 相似文献
8.
Shar S. Al‐Shihry Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(2):m40-m42
The title compound, [Fe(C5H5)(C21H21O3)], was obtained from successive Stobbe condensations between ketones and dimethyl succinate. The succinic anhydride five‐membered ring is distorted significantly from planarity, with the butadiene moiety being twisted by 49.3 (2)° from planarity and the C atoms at the succinic anhydride end of the alkene bonds showing significant pyramidalization. The cyclopentadiene rings of the ferrocenyl moiety adopt an almost eclipsed conformation. 相似文献
9.
Vratislav Langer Miroslav Ko Dalma Gyepesov Juraj Kronek Jozef Lusto Mariana Sldkovi
ov 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(10):o602-o606
Crystal structures are reported for three isomeric compounds, namely 2‐(2‐hydroxyphenyl)‐2‐oxazoline, (I), 2‐(3‐hydroxyphenyl)‐2‐oxazoline, (II), and 2‐(4‐hydroxyphenyl)‐2‐oxazoline, (III), all C9H9NO2 [systematic names: 2‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol, (I), 3‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol, (II), and 4‐(4,5‐dihydro‐1,3‐oxazol‐2‐yl)phenol, (III)]. In these compounds, the deviation from coplanarity of the oxazoline and benzene rings is dependent on the position of the hydroxy group on the benzene ring. The coplanar arrangement in (I) is stabilized by a strong intramolecular O—H⋯N hydrogen bond. Surprisingly, the 2‐oxazoline ring in molecule B of (II) adopts a 3T4 (C2TC3) conformation, while the 2‐oxazoline ring in molecule A, as well as that in (I) and (III), is nearly planar, as expected. Tetramers of molecules of (II) are formed and they are bound together via weak C—H⋯N hydrogen bonds. In (III), strong intermolecular O—H⋯N hydrogen bonds and weak intramolecular C—H⋯O hydrogen bonds lead to the formation of an infinite chain of molecules perpendicular to the b direction. This paper also reports a theoretical investigation of hydrogen bonds, based on density functional theory (DFT) employing periodic boundary conditions. 相似文献
10.
Functionalized 5‐(arylselanyl)‐2‐(arylsulfanyl)benzoates were prepared by [3+3] cyclocondensation of 3‐(arylsulfanyl)‐1‐(silyloxy)buta‐1,3‐dienes with 2‐(arylselanyl)‐3‐(silyloxy)‐alk‐2‐en‐1‐ones. 相似文献
11.
Vijayakumar N. Sonar Sean Parkin Peter A. Crooks 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(12):o743-o745
The title compounds, C20H17NO3S, (I), and C19H15NO2S, (II), were prepared by the reaction of benzo[b]thiophene‐2‐carbaldehyde with (3,4,5‐trimethoxyphenyl)acetonitrile and (3,4‐dimethoxyphenyl)acetonitrile, respectively, in the presence of methanolic potassium hydroxide. In (I), the C=C bond linking the benzo[b]thiophene and the 3,4,5‐trimethoxyphenyl units has E geometry, with dihedral angles between the plane of the bridging unit and the planes of the two adjacent ring systems of 5.2 (3) and 13.1 (2)°, respectively. However, in (II), the C=C bond has Z geometry, with dihedral angles between the plane of the bridging unit and the planes of the adjacent benzo[b]thiophene and 3,4‐dimethoxyphenyl units of 4.84 (17) and 76.09 (7)°, respectively. There are no significant intermolecular hydrogen‐bonding interactions in the packing of (I) and (II). The packing is essentially stabilized via van der Waals forces. 相似文献
12.
Carlos A. Escobar Oscar Donoso‐Tauda Ramiro Araya‐Maturana Andrs Vega 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):o426-o430
The 1,5‐benzodiazepine ring system exhibits a puckered boat‐like conformation for all four title compounds [4‐(2‐hydroxyphenyl)‐2‐phenyl‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C21H18N2O, (I), 2‐(2,3‐dimethoxyphenyl)‐4‐(2‐hydroxyphenyl)‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C23H22N2O3, (II), 2‐(3,4‐dimethoxyphenyl)‐4‐(2‐hydroxyphenyl)‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C23H22N2O3, (III), and 2‐(2,5‐dimethoxyphenyl)‐4‐(2‐hydroxyphenyl)‐2,3‐dihydro‐1H‐1,5‐benzodiazepine, C23H22N2O3, (IV)]. The stereochemical correlation of the two C6 aromatic groups with respect to the benzodiazepine ring system is pseudo‐equatorial–equatorial for compounds (I) (the phenyl group), (II) (the 2,3‐dimethoxyphenyl group) and (III) (the 3,4‐dimethoxyphenyl group), while for (IV) (the 2,5‐dimethoxyphenyl group) the system is pseudo‐axial–equatorial. An intramolecular hydrogen bond between the hydroxyl OH group and a benzodiazepine N atom is present for all four compounds and defines a six‐membered ring, whose geometry is constant across the series. Although the molecular structures are similar, the supramolecular packing is different; compounds (I) and (IV) form chains, while (II) forms dimeric units and (III) displays a layered structure. The packing seems to depend on at least two factors: (i) the nature of the atoms defining the hydrogen bond and (ii) the number of intermolecular interactions of the types O—H...O, N—H...O, N—H...π(arene) or C—H...π(arene). 相似文献
13.
Lakshminarasimhan Damodharan Vasantha Pattabhi Manoranjan Behera Sambasivarao Kotha 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(4):o216-o218
The title compounds, C19H19I2NO3 and C19H19Br2NO3, are derivatives of α‐aminoisobutyric acid with halogen substituents at the para and meta positions, respectively. The ethoxycarbonyl and formamide side chains attached to the Cα atom of the molecule adopt extended and folded conformations, respectively. The crystal structures are stabilized by N—H⃛O, C—H⃛O, C—Br⃛O and C—I⃛O interactions. 相似文献
14.
Satish S. More Akula Raghunadh Ramanathan Shankar Navin B. Patel Dinesh S. Bhalerao Unniaran K. Syam Kumar 《Helvetica chimica acta》2014,97(3):404-413
The first total synthesis of the α‐oxo amide‐based natural product, N‐(3‐guanidinopropyl)‐2‐(4‐hydroxyphenyl)‐2‐oxoacetamide ( 3 ), isolated from aqueous extracts of hydroid Campanularia sp., has been achieved. The α‐oxo amide 12 , prepared via the oxidative amidation of 1‐[4‐(benzyloxy)phenyl]‐2,2‐dibromoethanone ( 9a ) with 4‐{[(tert‐butyl)(dimethyl)silyl]oxy}butan‐1‐amine ( 10a ), has been used as the key intermediate in the total synthesis of 3 as HBr salt. On the way, an expeditious total synthesis of polyandrocarpamide C ( 2c ), isolated from marine ascidian Polyandrocarpa sp., was carried out in four steps. 相似文献
15.
Juana E. Prez‐Vargas Francisco J. Martínez‐Martínez Itzia I. Padilla‐Martínez Herbert Hpfl Efrn V. García‐Bez 《Acta Crystallographica. Section C, Structural Chemistry》2004,60(7):o517-o519
The title compound, C16H19NO5, crystallizes as a centrosymmetric dimer through strong O—H⋯O hydrogen‐bonding interactions between the hydroxyphenyl and morpholinocarbonyl groups. The morpholinocarbonyl group is almost perpendicular to the propenoate moiety. Electron delocalization in the N—C(=O) fragment leads to the formation of hydrogen‐bonded S(5) ring motifs through C—H⋯O interactions. 相似文献
16.
Michael G. S. Londesborough Jonathan Bould Josef Holub John D. Kennedy Mark Thornton‐Pett Bohumil tíbr 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(12):1423-1424
The title compound, 1,1,2,2‐tetracarbonyl‐1,2‐μ‐carbonyl‐4,11‐dimethylsulfido‐closo‐1,2‐dicobaltadodecaborane, [Co2(C4H20B10S2)(CO)5], has a closo 12‐vertex {1,2‐Co2B10H8} structure with SMe2 ligands at the exo‐4‐ and 11‐positions. The cluster displays close structural similarities to the SEt2 analogue. 相似文献
17.
Tomasz Manszewski Dorota Prukaa Wiesaw Prukaa Maciej Kubicki 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(10):o493-o495
The crystal structures of the two title (E)‐stilbazolium halogenates, C20H17ClNO+·Cl− and C20H17BrNO+·Br−, are isomorphous, with an isostructurality index of 0.985. The azastyryl fragments are almost planar, with dihedral angles between the benzene and pyridine rings of ca 4.5°. The rings of the benzyl groups are, in turn, almost perpendicular to the azastyryl planes, with dihedral angles larger than 80°. The cations and anions are connected by O—H...X− (X = halogen) hydrogen bonds. The halide anions are `sandwiched' between the charged pyridinium rings of neighbouring molecules, and weak C—H...O hydrogen bonds and C—H...X and C—H...π interactions also contribute to the crystal structures. 相似文献
18.
Morten Brndvang Lise‐Lotte Gundersen 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(5):o274-o276
The title compound, C17H13ClN4O2, displays profound and selective activity against Mycobacterium tuberculosis. In the crystal structure, there are two independent molecules in the asymmetric unit. Intermolecular hydrogen bonding between a CH group of the purine ring and the O atom of the furan ring, and also π–π stacking in another direction, builds the three‐dimensional network. 相似文献
19.
C. Wang Y. Wan H.‐Y. Wang L.‐L. Zhao J.‐J. Shi X.‐X. Zhang H. Wu 《Journal of heterocyclic chemistry》2013,50(3):496-500
The efficient one‐pot syntheses of Betti bases by the three‐component reaction of aromatic aldehyde, 2‐naphthalen, and acetonitrile (or benzamide) catalyzed by 1‐methyl‐3‐(2‐(sulfooxy)ethyl)‐1H‐imidazol‐3‐ium chloride is reported. The solvent can be recycled easily. 相似文献
20.
Sankar Prasad Dey Dilip Kumar Dey Asok Kumar Mallik Lutz Dahlenburg 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):o321-o322
The title compound, 2‐hydroxyphenyl 5‐(pyrrol‐2‐yl)‐3H‐pyrrolizin‐6‐yl ketone, C18H14N2O2, was isolated from the base‐catalyzed 1:2 condensation of 2‐hydroxyacetophenone with pyrrole‐2‐carbaldehyde. The pyrrole N—H and hydroxybenzoyl O—H groups are hydrogen bonded to the benzoyl O atom. The allylic C=C double bond of the 3H‐pyrrolizine system is located between ring positions 1 and 2, the C atom at position 3 (adjacent to the N atom) being single bonded. 相似文献