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1.
Enantioselective Synthesis of Highly Functionalized Dihydrofurans through Copper‐Catalyzed Asymmetric Formal [3+2] Cycloaddition of β‐Ketoesters with Propargylic Esters
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Fu‐Lin Zhu Ya‐Hui Wang De‐Yang Zhang Prof. Dr. Jie Xu Prof. Dr. Xiang‐Ping Hu 《Angewandte Chemie (International ed. in English)》2014,53(38):10223-10227
An enantioselective synthesis of highly functionalized dihydrofurans through a copper‐catalyzed asymmetric [3+2] cycloaddition of β‐ketoesters with propargylic esters has been developed. With a combination of Cu(OTf)2 and a chiral tridentate P,N,N ligand as the catalyst, a variety of 2,3‐dihydrofurans bearing an exocyclic double bond at the 2 position were obtained in good chemical yields and with good to high enantioselectivities. The exocyclic double bond can be hydrogenated in a highly diastereoselective fashion to give unusual cis‐2,3‐dihydrofuran derivatives, thus further enhancing the scope of this transformation. 相似文献
2.
Alexander S. Lyakhov Pavel N. Gaponik Michail M. Degtyarik Ludmila S. Ivashkevich 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(6):m204-m206
In the polymeric title complex, [CuCl2(C3H6N4)2]n, there are two ligands in the asymmetric unit. The Cu atom adopts an elongated octahedral geometry, with two 2‐ethyltetrazole ligands [Cu—N = 2.0037 (16) and 2.0136 (16) Å] and two Cl atoms [Cu—Cl = 2.2595 (6) and 2.2796 (6) Å] in equatorial positions. A Cl atom and a symmetry‐related 2‐ethyltetrazole molecule [Cu—Cl = 2.8845 (8) Å and Cu—N = 2.851 (2) Å] lie in the axial positions of the octahedron. One of the two 2‐ethyltetrazole ligands of the asymmetric unit exhibits bidentate binding to two Cu atoms through two N atoms of the tetrazole ring, whereas the other ligand is coordinated in a monodentate fashion via one tetrazole N atom. The Cu‐atom octahedra form dimer entities by sharing edges with equatorial and axial Cl atoms. The dimers are linked together through the 2‐ethyltetrazole ligands to form one‐dimensional polymeric zigzag chains extending along the b axis. The chains are connected into infinite layers parallel to the (10) plane via the 2‐ethyltetrazole ligands. 相似文献
3.
Tomoka Yamaguchi Yukinari Sunatsuki Hiroyuki Ishida 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(4):m156-m160
In the crystal structures of both title compounds, [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]nickel(II) [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]nickel(II) chloride methanol disolvate, [Ni(C26H25.5N3O3)]2Cl·2CH4O, and [1,3‐bis(2‐hydroxybenzylidene)‐2‐methyl‐2‐(2‐oxidobenzylideneaminomethyl)propane‐1,3‐diamine]zinc(II) perchlorate [2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methyl‐1,3‐bis(2‐oxidobenzylidene)propane‐1,3‐diamine]zinc(II) methanol trisolvate, [Zn(C26H25N3O3)]ClO4·[Zn(C26H26N3O3)]·3CH4O, the 3d metal ion is in an approximately octahedral environment composed of three facially coordinated imine N atoms and three phenol O atoms. The two mononuclear units are linked by three phenol–phenolate O—H...O hydrogen bonds to form a dimeric structure. In the Ni compound, the asymmetric unit consists of one mononuclear unit, one‐half of a chloride anion and a methanol solvent molecule. In the O—H...O hydrogen bonds, two H atoms are located near the centre of O...O and one H atom is disordered over two positions. The NiII compound is thus formulated as [Ni(H1.5L)]2Cl·2CH3OH [H3L is 1,3‐bis(2‐hydroxybenzylidene)‐2‐(2‐hydroxybenzylideneaminomethyl)‐2‐methylpropane‐1,3‐diamine]. In the analogous ZnII compound, the asymmetric unit consists of two crystallographically independent mononuclear units, one perchlorate anion and three methanol solvent molecules. The mode of hydrogen bonding connecting the two mononuclear units is slightly different, and the formula can be written as [Zn(H2L)]ClO4·[Zn(HL)]·3CH3OH. In both compounds, each mononuclear unit is chiral with either a Δ or a Λ configuration because of the screw coordination arrangement of the achiral tripodal ligand around the 3d metal ion. In the dimeric structure, molecules with Δ–Δ and Λ–Λ pairs co‐exist in the crystal structure to form a racemic crystal. A notable difference is observed between the M—O(phenol) and M—O(phenolate) bond lengths, the former being longer than the latter. In addition, as the ionic radius of the metal ion decreases, the M—O and M—N bond distances decrease. 相似文献
4.
Lesaw Siero Katarzyna Kie‐Kononowicz Janina Karolak‐Wojciechowska 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(2):m79-m82
The two title mononuclear compounds are four‐coordinate bis[N‐(5‐oxo‐4,4‐diphenyl‐4,5‐dihydro‐1H‐imidazolidin‐2‐ylidene)glycinato]copper(II) dimethylformamide disolvate, [Cu(C17H14N3O3)2]·2C3H7NO, (I), and five‐coordinate aquabis[N‐(5‐oxo‐4,4‐diphenyl‐4,5‐dihydro‐1H‐imidazolidin‐2‐ylidene)glycinato]copper(II) dimethylformamide disolvate, [Cu(C17H14N3O3)2(H2O)]·2C3H7NO, (II). In (I), the CuII ion lies on an inversion centre with one‐half of the complex molecule in the asymmetric unit, while in (II) there are two independent ligand molecules in the asymmetric unit, with the CuII ion and coordinated water molecule located on a general position. In both crystal structures, the complex molecules assemble in ribbons via N—H...O hydrogen‐bond networks. 相似文献
5.
Guo‐Qing Bian Takayoshi Kuroda‐Sowa Sayuri Sugimoto Masahiko Maekawa Megumu Munakata 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):m144-m146
The title one‐dimensional chain polymer complex, [Mn(C6H4NO3)Cl(C6H5N)2]n, was isolated from the reaction of MnCl2 with 6‐oxo‐1,6‐dihydropyridine‐2‐carboxylic acid (HpicOH) in pyridine. The asymmetric unit contains one [Mn(HPicO)Cl(py)2] moiety (py is pyridine), with the (HpicO)− ligand acting in a tridentate manner via the two carboxylate O atoms and the pyridone O atom. The operation of inversion centres generates eight‐ and 14‐membered rings and, in conjunction with an a‐axis translation, leads to an infinite chain extending along [100]. The Mn⋯Mn separations in this chain are 5.1069 (6) and 7.1869 (6) Å. The MnII atom has a distorted octahedral coordination, with trans‐axial pyridine ligands and with three O atoms and the Cl atom in the equatorial plane. The conformation of the 14‐membered ring is stabilized by pairs of inversion‐related N—H⋯O hydrogen bonds. 相似文献
6.
A Phosphine‐Catalyzed Novel Asymmetric [3+2] Cycloaddition of C,N‐Cyclic Azomethine Imines with δ‐Substituted Allenoates
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Dr. De Wang Yu Lei Dr. Yin Wei Prof. Dr. Min Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(47):15325-15329
Catalytic asymmetric [3+2] cycloadditions of C,N‐cyclic azomethine imines with δ‐substituted allenoates have been developed in the presence of (S)‐Me‐f‐KetalPhos, affording functionalized tetrahydroquinoline frameworks in good yields with high diastereo‐ and good enantioselectivities under mild condition. The substrate scope has been also examined. This is the first time that δ‐substituted allenoates have been applied as a δ,γ‐C?C bond participated C2 synthon in asymmetric synthesis. 相似文献
7.
Daphne E. Keller Huub Kooijman Antoine M. M. Scheurs Jan Kroon Eugeniusz Grech 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(4):479-480
The structure of the title compound, C14H19N2+·C9H3Cl6O4?·H2O, consists of singly ionized 1,4,5,6,7,7‐hexachlorobicyclo[2.2.1]hept‐5‐ene‐2,3‐dicarboxylic acid anions and protonated 1,8‐bis(dimethylamino)naphthalene cations. In the (8‐dimethylamino‐1‐napthyl)dimethylammonium cation, a strong disordered intramolecular hydrogen bond is formed with N?N = 2.589 (3) Å. The geometry and occupancy obtained in the final restrained refinement suggest that the disordered hydrogen bond may be asymmetric. Water molecules link the anion dimers into infinite chains via hydrogen bonding. 相似文献
8.
Ligia Rebelo Gomes John Nicolson Low Ana S. M. C. Rodrigues James L. Wardell Marcus V. N. de Souza Thais C. M. Noguiera Alessandra C. Pinheiro 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(8):920-926
(E)‐2‐(2‐Benzylidenehydrazinylidene)quinoxaline, C15H12N4, crystallized with two molecules in the asymmetric unit. The structures of six halogen derivatives of this compound were also investigated: (E)‐2‐[2‐(2‐chlorobenzylidene)hydrazinylidene]quinoxaline, C15H11ClN4; (E)‐2‐[2‐(3‐chlorobenzylidene)hydrazinylidene]quinoxaline, C15H11ClN4; (E)‐2‐[2‐(4‐chlorobenzylidene)hydrazinylidene]quinoxaline, C15H11ClN4; (E)‐2‐[2‐(2‐bromobenzylidene)hydrazinylidene]quinoxaline, C15H11BrN4; (E)‐2‐[2‐(3‐bromobenzylidene)hydrazinylidene]quinoxaline, C15H11BrN4; (E)‐2‐[2‐(4‐bromobenzylidene)hydrazinylidene]quinoxaline, C15H11BrN4. The 3‐Cl and 3‐Br compounds are isomorphous, as are the 4‐Cl and 4‐Br compounds. In all of these compounds, it was found that the supramolecular structures are governed by similar predominant patterns, viz. strong intermolecular N—H...N(pyrazine) hydrogen bonds supplemented by weak C—H...N(pyrazine) hydrogen‐bond interactions in the 2‐ and 3‐halo compounds and by C—H...Cl/Br interactions in the 4‐halo compounds. In all compounds, there are π–π stacking interactions. 相似文献
9.
Ligia Gomes John Nicolson Low Mrio A. D. C. Valente Cristina Freire Baltazar Castro 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):m293-m296
The title complex, [Cu(C12H9N2O)(C2H3O2)(C12H10N2O)], is a neutral CuII complex with a primary N3O2 coordination sphere. The Cu centre coordinates to both a deprotonated and a neutral molecule of N‐phenylpyridine‐2‐carboxamide and also to an acetate anion. The coordination around the metal centre is asymmetric, the deprotonated ligand providing two N donor atoms [Cu—N = 1.995 (2) and 2.013 (2) Å] and the neutral ligand providing one N and one O donor atom to the coordination environment [Cu—N = 2.042 (2) Å and Cu—O = 2.2557 (19) Å], the fifth donor being an O atom of the acetate ion [Cu—O = 1.9534 (19) Å]. The remaining O atom from the acetate ion can be considered as a weak donor atom [Cu—O = 2.789 (2) Å], conferring to the Cu complex an asymmetric octahedral geometry. The crystal structure is stabilized by intermolecular N—H...O, C—H...O and C—H...π interactions. 相似文献
10.
Hye Mi Oh Ji Eun Park Jisu Kim Ju Hyun Kim Prof. Youn K. Kang Prof. Young Keun Chung 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(29):9024-9036
A method for the synthesis of bicyclo[4.1.0]heptenes from 1,6‐enynes through Pd‐catalyzed cycloisomerization has been developed. N‐ and O‐tethered 1,6‐enynes were successfully transformed to their corresponding 3‐aza‐ and 3‐oxabicyclo[4.1.0]heptenes in reasonable‐to‐high yields using the catalysts [PdCl2(CH3CN)2]/P(OPh)3 or [Pd(maleimidate)2(PPh3)2] in toluene. The computational calculations using density functional theory indicate that [PdCl2{P(OPh)3}] in the oxidation state PdII acts as the active catalyst species for the formation of 3‐azabicyclo[4.1.0]heptenes through 6‐endo‐dig cyclization. 相似文献
11.
Dmitry A. Piryazev Mikhail A. Ogienko Alexander V. Virovets Nikolay A. Pushkarevsky Sergey N. Konchenko 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(11):m320-m322
The sterically hindered title complex, [Fe3Te2(C36H40N2)(CO)7], was obtained by substitution of two carbonyl groups in the [Fe3(μ3‐Te)2(CO)9] cluster by the bulky redox‐active N,N′‐bis(2,6‐diisopropylphenyl)acenaphthene‐1,2‐diimine (dpp‐BIAN) ligand. The asymmetric unit contains two molecules of the same geometry. The C=N bond lengths in dpp‐BIAN indicate a rather low level of electron transfer from the cluster core to the dpp‐BIAN ligand. 相似文献
12.
Hong‐Chang Liang Marcel M. Hetu Kraig A. Wheeler Lev N. Zakharov Arnold L. Rheingold 《Acta Crystallographica. Section C, Structural Chemistry》2006,62(11):m519-m521
In the title compound, [Zn(C2H3N)(C16H21N3O)](ClO4)2·H2O, the ZnII ion is coordinated by two pyridyl N atoms, one amine N atom, and an ethanol O atom from the N,N′,N′′,O‐tetradentate 2‐[bis(2‐pyridylethyl)amino]ethanol donor ligand. The fifth coordination site is filled by an acetonitrile N atom, and there is one solvent water molecule in the asymmetric unit. The 2+ charge of the cationic portion of the complex is balanced by two perchlorate counter‐anions. 相似文献
13.
Zora Popovi Gordana Pavlovi Dubravka Matkovi‐alogovi
eljka Soldin 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(5):m165-m167
The asymmetric unit of the title polymeric complex, [HgBr(C6H4NO2)]n or HgBr(nic), contains mercury coordinated via two Br atoms [Hg—Br = 2.6528 (9) and 2.6468 (9) Å], two carboxylate O atoms, which form a characteristic four‐membered chelate ring [Hg—O = 2.353 (6) and 2.478 (7) Å], and an N atom [Hg—N = 2.265 (5) Å], in the form of a very irregular (3+2)‐coordination polyhedron. The pronounced irregularity of the effective Hg (3+2)‐coordination is a result of the rigid stereochemistry of the nicotinate ligand. According to the covalent and van der Waals radii criteria, the strongest bonds are Hg—Br and Hg—N. These covalent interactions form a two‐dimensional polymer. The puckered planes are connected by van der Waals interactions, and there are only two intermolecular C—H⋯O hydrogen bonds [3.428 (10) and 3.170 (10) Å]. 相似文献
14.
Guo‐Wu Lin Yue Wang Tao Lu 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(4):m179-m181
The title compound, [Co(C19H15N3O5S)(C12H8N2)]·5H2O, has a moderately distorted octahedral coordination environment composed of two N atoms of a 1,10‐phenanthroline ligand and one N and three O atoms of an N‐{[4‐(1,3‐benzothiazol‐2‐yl)anilino]carbonylmethyl}iminodiacetate (ZL‐52−) ligand. The ring systems of the phenanthroline and ZL‐52− ligands are coplanar and the complexes pack in layers parallel to the ab plane with the rings of adjacent complexes facing one another. The layers stack along the c axis and are linked by hydrogen bonds involving the five water solvent molecules in the asymmetric unit and O atoms of the acetate groups of the ZL‐52− ligand. This is believed to be the first crystal structure of a complex of a 2‐(4‐aminophenyl)benzothiazole ligand. 相似文献
15.
Alexander S. Lyakhov Pavel N. Gaponik Michail M. Degtyarik Vadim E. Matulis Vitaly E. Matulis Ludmila S. Ivashkevich 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):m90-m92
In the crystal structure of the title compound, [Cu3Cl6(C4H6N4)4]n, there are three Cu atoms, six Cl atoms and four 2‐allyltetrazole ligands in the asymmetric unit. The polyhedron of one Cu atom adopts a flattened octahedral geometry, with two 2‐allyltetrazole ligands in the axial positions [Cu—N4 = 1.990 (2) and 1.991 (2) Å] and four Cl atoms in the equatorial positions [Cu—Cl = 2.4331 (9)–2.5426 (9) Å]. The polyhedra of the other two Cu atoms have a square‐pyramidal geometry, with three basal sites occupied by Cl atoms [Cu—Cl = 2.2487 (9)–2.3163 (8) and 2.2569 (9)–2.3034 (9) Å] and one basal site occupied by a 2‐allyltetrazole ligand [Cu—N4 = 2.028 (2) and 2.013 (2) Å]. A Cl atom lies in the apical position of either pyramid [Cu—Cl = 2.8360 (10) and 2.8046 (9) Å]. The possibility of including the tetrazole N3 atoms in the coordination sphere of the two Cu atoms is discussed. Neighbouring copper polyhedra share their edges with Cl atoms to form one‐dimensional polymeric chains running along the a axis. 相似文献
16.
John Nicolson Low Justo Cobo Manuel Nogueras Adolfo Snchez Braulio Insuasty Harlen Torres 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):o39-o41
2,2‐Dimethyl‐5‐[3‐(4‐methylphenyl)‐2‐propenylidene]‐1,3‐dioxane‐4,6‐dione, C16H16O4, crystallizes in the triclinic space group , with two molecules in the asymmetric unit. These molecules and a centrosymmetrically related pair, linked together by weak C—H?O hydrogen bonds, form a tetramer. 5‐[3‐(4‐Chlorophenyl)‐2‐propenylidene]‐2,2‐dimethyl‐1,3‐dioxane‐4,6‐dione, C15H13ClO4, also crystallizes in the triclinic space group , with one molecule in the asymmetric unit. Centrosymmetrically related molecules are linked together by weak C—H?O hydrogen bonds to form dimers which are further linked by yet another pair of centrosymmetrically related C—H?O hydrogen bonds to form a tube which runs parallel to the a axis. 相似文献
17.
Heterobimetallic Complexes of Lithium, Aluminum, and Gold with the N ‐[2‐ N ′, N ′‐(dimethylaminoethyl)‐ N ‐methyl‐aminoethyl]‐ferrocenyl Ligand (η5‐C5H5)Fe{η5‐C5H3[CH(CH3)N(CH3)CH2CH2NMe2]‐2} N‐[2‐N′,N′‐(dimethylaminoethyl)‐N‐methyl‐aminoethyl]ferrocene FcN,NH ( 1 ) reacts with nBuLi under formation of the lithium organyl (FcN,N)Li ( 2 ). At reactions of 2 with AlBr3 and AuCl · PPh3 the heterobimetallic organo derivatives (FcN,N)AlBr2 ( 3 ), (FcN,N)Au · PPh3 ( 4 ) are formed. A detailed characterization of 2 – 4 was carried out by single crystal x‐ray analyses as well as by NMR and Mößbauer spectroscopy. 相似文献
18.
The asymmetric hydroformylation of 2‐ and 3‐vinylfurans ( 2a and 2b , resp.) was investigated by using [Rh{(R,S)‐binaphos}] complexes as catalysts ((R,S)‐binaphos = (11bS)‐4‐{[1R)‐2′‐phosphino[1,1′‐binaphthalen]‐2‐yl]oxy}dinaphtho[2,1‐d:1′,2′‐f][1,3,2]dioxaphosphepin; 1 ). Hydroformylation of 2 gave isoaldehydes 3 in high regio‐ and enantioselectivities (Scheme 2 and Table). Reduction of the aldehydes 3 with NaBH4 successfully afforded the corresponding alcohols 5 without loss of enantiomeric purity (Scheme 3). 相似文献
19.
Jaime Portilla Diego Estupian Justo Cobo Christopher Glidewell 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(3):o133-o136
The title compound, C19H16N6, crystallizes with Z′ = 2 in the space group P21/n. The two molecules in the selected asymmetric unit are approximate mirror images of one another; most corresponding pairs of atoms are related by an approximate half‐cell translation along [100]. Each molecule contains an intramolecular N—H...N hydrogen bond and the molecules are linked into complex sheets by a combination of two intermolecular N—H...N and four C—H...π(arene) hydrogen bonds. Comparisons are made with some other 7‐aminopyrazolo[1,5‐a]pyrimidines. 相似文献
20.
Zora Popovi Gordana Pavlovi Boris‐Marko Kukovec 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(5):m181-m183
The title compound, [Cu(C9H5N2O3)2(C2H6OS)2], consists of octahedrally coordinated CuII ions, with the 3‐oxo‐3,4‐dihydroquinoxaline‐2‐carboxylate ligands acting in a bidentate manner [Cu—O = 1.9116 (14) Å and Cu—N = 2.1191 (16) Å] and a dimethyl sulfoxide (DMSO) molecule coordinated axially via the O atom [Cu—O = 2.336 (5) and 2.418 (7) Å for the major and minor disorder components, respectively]. The whole DMSO molecule exhibits positional disorder [0.62 (1):0.38 (1)]. The octahedron around the CuII atom, which lies on an inversion centre, is elongated in the axial direction, exhibiting a Jahn–Teller effect. The ligand exhibits tautomerization by H‐atom transfer from the hydroxyl group at position 3 to the N atom at position 4 of the quinoxaline ring of the ligand. The complex molecules are linked through an intermolecular N—H...O hydrogen bond [N...O = 2.838 (2) Å] formed between the quinoxaline NH group and a carboxylate O atom, and by a weak intermolecular C—H...O hydrogen bond [3.392 (11) Å] formed between a carboxylate O atom and a methyl C atom of the DMSO ligand. There is a weak intramolecular C—H...O hydrogen bond [3.065 (3) Å] formed between a benzene CH group and a carboxylate O atom. 相似文献