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1.
Olivier Vallat Ana‐Maria Buciumas Reinhard Neier Helen Stoeckli‐Evans 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(4):o171-o175
The title compounds, rac‐(1′R,2R)‐tert‐butyl 2‐(1′‐hydroxyethyl)‐3‐(2‐nitrophenyl)‐5‐oxo‐2,5‐dihydro‐1H‐pyrrole‐1‐carboxylate, C17H20N2O6, (I), rac‐(1′S,2R)‐tert‐butyl 2‐[1′‐hydroxy‐3′‐(methoxycarbonyl)propyl]‐3‐(2‐nitrophenyl)‐5‐oxo‐2,5‐dihydro‐1H‐pyrrole‐1‐carboxylate, C20H24N2O8, (II), and rac‐(1′S,2R)‐tert‐butyl 2‐(4′‐bromo‐1′‐hydroxybutyl)‐5‐oxo‐2,5‐dihydro‐1H‐pyrrole‐1‐carboxylate, C13H20BrNO4, (III), are 5‐hydroxyalkyl derivatives of tert‐butyl 2‐oxo‐2,5‐dihydropyrrole‐1‐carboxylate. In all three compounds, the tert‐butoxycarbonyl (Boc) unit is orientated in the same manner with respect to the mean plane through the 2‐oxo‐2,5‐dihydro‐1H‐pyrrole ring. The hydroxyl substituent at one of the newly created chiral centres, which have relative R,R stereochemistry, is trans with respect to the oxo group of the pyrrole ring in (I), synthesized using acetaldehyde. When a larger aldehyde was used, as in compounds (II) and (III), the hydroxyl substituent was found to be cis with respect to the oxo group of the pyrrole ring. Here, the relative stereochemistry of the newly created chiral centres is R,S. In compound (I), O—H...O hydrogen bonding leads to an interesting hexagonal arrangement of symmetry‐related molecules. In (II) and (III), the hydroxyl groups are involved in bifurcated O—H...O hydrogen bonds, and centrosymmetric hydrogen‐bonded dimers are formed. The Mukaiyama crossed‐aldol‐type reaction was successful when using the 2‐nitrophenyl‐substituted hydroxypyrrole, or the unsubstituted hydroxypyrrole, and boron trifluoride diethyl ether as catalyst. The synthetic procedure leads to a syn configuration of the two newly created chiral centres in all three compounds. 相似文献
2.
2,3‐Dihydrothiophene 1,1‐dioxide (‘2‐sulfolene’) reacted with tosylmethyl isocyanide (TsMIC) in the presence of a base to give the hitherto unknown 3,5‐dihydro‐2H‐thieno[2,3‐c]pyrrole 1,1‐dioxide (‘β′‐sulfolenopyrrole’) from the expected cyclocondensation. A serendipitous formation of this β′‐sulfolenopyrrole was found earlier, when we investigated synthetic routes to a 3,5‐dihydro‐1H‐thieno[3,4‐c]pyrrole 2,2‐dioxide (a ‘β″‐sulfolenopyrrole’) from TsMIC and 2,5‐dihydrothiophene 1,1‐dioxide (‘3‐sulfolene’). Here, we present the synthesis and characterization of β′‐sulfolenopyrrole. The X‐ray crystal‐structure analyses of β′‐sulfolenopyrrole and the isomeric β″‐sulfolenopyrrole are also reported here. This β′‐sulfolenopyrrole is a new type of a functionalized pyrrole, which is likely to be of interest for pharmaceutical purposes. 相似文献
3.
《Helvetica chimica acta》2018,101(5)
Heteroleptic Ru(II) complexes were designed based on 4,4′‐bis((E)‐styryl)‐2,2′‐bipyridine (bsbpy) as an ancillary ligand for dye‐sensitized solar cells (DSSCs), and those Ru(II) sensitizers, [Ru(L)(bsbpy)(NCS)2][TBA] (TBA; tetrabutylammonium), were synthesized according to a typical one‐pot reaction of [RuCl2(p‐cymene)]2 with the corresponding anchoring ligands (where L = 4,4′‐dicarboxy‐2,2′‐bipyridine (dcbpy), 4,4′‐bis((E)‐carboxyvinyl)‐2,2′‐bipyridine (dcvbpy), 4,7‐dicarboxy‐1,10‐phenanthroline (dcphen), or 4,7‐bis((E)‐carboxyvinyl)‐1,10‐phenanthroline (dcvphen)). The new Ru(II) dyes, [Ru(L)(bsbpy)(NCS)2][TBA] that incorporated vinyl spacer(s) into ancillary and/or anchoring ligand displayed red‐shifted bands over the overall UV/VIS region relative to the absorption spectra of N719 . A combination of bsbpy ancillary and dcphen anchoring ligand showed the best result for the overall power conversion efficiency (η); i.e., a DSSC fabricated with [Ru(dcphen)(bsbpy)(NCS)2][TBA] exhibited a power conversion efficiency (η) of 2.98% (compare to N719 , 4.82%). 相似文献
4.
Igor N. Zyuzin Kyrill Yu. Suponitsky Aleksei B. Sheremetev 《Journal of heterocyclic chemistry》2012,49(3):561-565
The first synthesis of 4,8‐dihydro‐bis‐furazano[3,4‐b:3′4′‐e]pyrazine bearing 2,2‐bis(methoxy‐NNO‐azoxy)ethyl groups has been developed. These compounds are obtained by aza‐Michael reaction of 1,1‐bis(methoxy‐NNO‐azoxy)ethene or its equivalents, such as 2,2‐bis(methoxy‐NNO‐azoxy)ethanol derivatives, with 4,8‐dihydro‐bis‐furazano[3,4‐b:3′4′‐e]pyrazine. 相似文献
5.
Hong‐Tao Zhang Ting Shao Hua‐Qin Wang Xiao‐Zeng You 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(7):m259-m261
The asymmetric unit of the title compound, {[Ni(C12H6N2O4)(H2O)3]·H2O}n, is composed of a lattice water molecule and a nickel(II) ion that is coordinated by three water molecules and the two N atoms of a 2,2′‐bipyridine‐3,3′‐dicarboxylate ligand. The twist of the 2,2′‐bipyridine‐3,3′‐dicarboxylate unit and the coordination of one carboxylate group to a symmetry‐related NiII atom generate a helical chain that runs along the b axis. Intrahelical hydrogen bonds participate in controlling the orientation of the helices, and both right‐handed and left‐handed helices are connected by interhelical hydrogen bonds into two‐dimensional sheets. 相似文献
6.
Zheng‐Liang Lü Zhi‐Liang Liu De‐Qing Zhang 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(3):m147-m150
In the two isomorphous title compounds, viz. tris[2,2′‐bi(4,5‐dihydro‐1,3‐oxazole)‐κ2N,N′]copper(II) diperchlorate, [Cu(C6H8N2O2)3](ClO4)2, (I), and tris[2,2′‐bi(4,5‐dihydro‐1,3‐oxazole)‐κ2N,N′]nickel(II) diperchlorate, [Ni(C6H8N2O2)3](ClO4)2, (II), the MII ions each have a distorted octahedral coordination geometry formed via six N atoms from three 2,2′‐bioxazoline ligands. For each ligand, the two five‐membered rings are nearly coplanar. It is noteworthy that the Jahn–Teller effect is stronger in (I) than in (II). The three‐dimensional supramolecular structures of (I) and (II) are formed via weak hydrogen‐bonding interactions between O atoms from perchlorate anions and H atoms from 2,2′‐bioxazoline ligands. 相似文献
7.
Hong‐Ping Xiao Zhan Shi Long‐Guan Zhu Ru‐Ren Xu Wen‐Qin Pang 《Acta Crystallographica. Section C, Structural Chemistry》2003,59(3):m82-m83
The reaction of nickel(II) nitrate with terephthalic acid and 2,2′‐bipyridine in dimethylformamide solution gives the title complex, [Ni(C10H8N2)(H2O)4](C8H4O4). The NiII ion is octahedrally coordinated to one 2,2′‐bipyridine and four water molecules and does not coordinate to the terephthalate anion. Hydrogen bonds between the terephthalate anions and the [Ni(2,2′‐bipy)(H2O)4]2+ cations produce a two‐dimensional hydrogen‐bonding architecture with double sheets. 相似文献
8.
The reaction of 2,5‐dimethyl‐3,4‐diselenocyanato‐1H‐pyrrole by NaBH4 or NaOCH3 led to tetraselenide 7 in quantitative yield. Treatment of protected tetraselenide 8 with LiAlH4 afforded the aluminum complex intermediate that was converted into pyrrole‐annelated 1,3‐diselenolo‐2‐thione 9 in excellent yield. Similarly, treatment of tetraselenide 8 with LiAlH4 followed by TFA afforded 1,2‐diselenol intermediate that was converted into pyrrole‐annelated 1,3‐diselenolo‐2‐one 10 upon treatment of diimidazole carbonate. J. Heterocyclic Chem., (2011). 相似文献
9.
Vijay Mahadevan Iyer Helen Stoeckli‐Evans Anthony D'Alo Luisa De Cola Peter Belser 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(4):o259-o261
Structure analyses of 4,4′‐bis(4‐hydroxybutyl)‐2,2′‐bipyridine, C18H24N2O2, (I), and 4,4′‐bis(4‐bromobutyl)‐2,2′‐bipyridine, C18H22Br2N2, (II), reveal intermolecular hydrogen bonding in both compounds. For (I), O—H·N intermolecular hydrogen bonding leads to the formation of an infinite two‐dimensional polymer, and π stacking interactions are also observed. For (II), C—H·N intermolecular hydrogen bonding leads to the formation of a zigzag polymer. The two compounds crystallize in different crystal systems, but both molecules possess Ci symmetry, with one half molecule in the asymmetric unit. 相似文献
10.
《Acta Crystallographica. Section C, Structural Chemistry》2017,73(12):1109-1115
Two spiro[indoline‐3,3′‐pyrrolizine] derivatives have been synthesized in good yield with high regio‐ and stereospecificity using one‐pot reactions between readily available starting materials, namely l ‐proline, substituted 1H‐indole‐2,3‐diones and electron‐deficient alkenes. The products have been fully characterized by elemental analysis, IR and NMR spectroscopy, mass spectrometry and crystal structure analysis. In (1′RS ,2′RS ,3SR ,7a′SR )‐2′‐benzoyl‐1‐hexyl‐2‐oxo‐1′,2′,5′,6′,7′,7a′‐hexahydrospiro[indoline‐3,3′‐pyrrolizine]‐1′‐carboxylic acid, C28H32N2O4, (I), the unsubstituted pyrrole ring and the reduced spiro‐fused pyrrole ring adopt half‐chair and envelope conformations, respectively, while in (1′RS ,2′RS ,3SR ,7a′SR )‐1′,2′‐bis(4‐chlorobenzoyl)‐5,7‐dichloro‐2‐oxo‐1′,2′,5′,6′,7′,7a′‐hexahydrospiro[indoline‐3,3′‐pyrrolizine], which crystallizes as a partial dichloromethane solvate, C28H20Cl4N2O3·0.981CH2Cl2, (II), where the solvent component is disordered over three sets of atomic sites, these two rings adopt envelope and half‐chair conformations, respectively. Molecules of (I) are linked by an O—H…·O hydrogen bond to form cyclic R 66(48) hexamers of (S 6) symmetry, which are further linked by two C—H…O hydrogen bonds to form a three‐dimensional framework structure. In compound (II), inversion‐related pairs of N—H…O hydrogen bonds link the spiro[indoline‐3,3′‐pyrrolizine] molecules into simple R 22(8) dimers. 相似文献
11.
One‐Handed Single Helicates of Dinickel(II) Benzenehexapyrrole‐α,ω‐diimine with an Amine Chiral Source 下载免费PDF全文
Dr. Chaolu Eerdun Satoshi Hisanaga Prof. Dr. Jun‐ichiro Setsune 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(1):239-246
Benzenehexapyrrole‐α,ω‐dialdehyde, composed of a pair of formyltripyrrole units with a 1,3‐phenylene linker, was metallated to give dinuclear single‐stranded helicates. X‐ray studies of the bis‐nickel(II) complex showed a helical C2 form with a pair of helical–metal coordination planes of a 3N+O donor set. The terminal aldehyde was readily converted into the imine by optically active amines, whereby helix‐sense bias was induced. Bis‐nickel(II) and bis‐palladium(II) complexes of the benzenehexapyrrole‐α,ω‐diimines were studied to show that an enantiomer pair of the helical C2 form are interchanged by slow flipping of each coordination plane and fast rotation around the C(benzene)?C(pyrrole) bond. The helical screw in the bis‐nickel(II) complexes was biased to one side in more than 95 % diastereoselectivity, which was achieved by using a variety of optically active amines, such as (R)‐1‐cyclohexylethylamine, (S)‐1‐ phenylethylamine, L ‐Phe(OEt) (Phe=phenylalanine), and (R)‐valinol. The nickel complexes showed much better diastereoselectivity than the corresponding palladium complexes. 相似文献
12.
Pawe Wagner David L. Officer Maciej Kubicki 《Acta Crystallographica. Section C, Structural Chemistry》2007,63(7):o400-o404
In the crystal structures of four thiophene derivatives, (E)‐3′‐[2‐(anthracen‐9‐yl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C28H18S3, (E)‐3′‐[2‐(1‐pyrenyl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C30H18S3, (E)‐3′‐[2‐(3,4‐dimethoxyphenyl)ethenyl]‐2,2′:5′,2′′‐terthiophene, C22H18O2S3, and (E,E)‐1,4‐bis[2‐(2,2′:5′,2′′‐terthiophen‐3′‐yl)ethenyl]‐2,5‐dimethoxybenzene, C36H26O2S6, at least one of the terminal thiophene rings is disordered and the disorder is of the flip type. The terthiophene fragments are far from being coplanar, contrary to terthiophene itself. The central C—C=C—C fragments are almost planar but the bond lengths suggest slight delocalization within this fragment. The crystal packing is determined by van der Waals interactions and some weak, relatively short, C—H...S and C—H...π directional contacts. 相似文献
13.
The synthesis of the novel 2,4,6‐triaryl‐1‐(spiro[2H‐1‐benzopyran‐2,2′‐indoline]‐6‐yl)pyridiniumper‐chlorates 4 by reaction of 5 ‐nitrosalicylaldehydes 6 with 1,3,3‐trimethyl‐2‐methyleneindoline ( 7 ) to 6‐nitro‐spiro[2H‐1‐benzopyran‐2,2′‐indolines] 1 , their stannous chloride reduction to the 6‐amino derivatives 8 , followed by a 2,6‐[C5+N] ring transformation with 2,4,6‐triarylpyrylium perchlorates 9 , is reported. UV irradiation experiments in twenty solvents of different polarity prove their photochromic properties and show that the photochemically generated negative solvatochromic dyes 5 , formed by ring opening of the benzopyran moiety of 4 , are rather merocyanine than pyridinium phenolate betaine dyes. 相似文献
14.
A Noble‐Metal‐Free Nickel(II) Polypyridyl Catalyst for Visible‐Light‐Driven Hydrogen Production from Water 下载免费PDF全文
Dr. Yong‐Jun Yuan Dr. Hong‐Wei Lu Ji‐Ren Tu Dr. Yong Fang Dr. Zhen‐Tao Yu Dr. Xiao‐Xing Fan Prof. Zhi‐Gang Zou 《Chemphyschem》2015,16(14):2925-2930
The complex [Ni(bpy)3]2+ (bpy=2,2′‐bipyridine) is an active catalyst for visible‐light‐driven H2 production from water when employed with [Ir(dfppy)2(Hdcbpy)] [dfppy=2‐(3,4‐difluorophenyl)pyridine, Hdcbpy=4‐carboxy‐2,2′‐bipyridine‐4′‐carboxylate] as the photosensitizer and triethanolamine as the sacrificial electron donor. The highest turnover number of 520 with respect to the nickel(II) catalyst is obtained in a 8:2 acetonitrile/water solution at pH 9. The H2‐evolution system is more stable after the addition of an extra free bpy ligand, owing to faster catalyst regeneration. The photocatalytic results demonstrate that the nickel(II) polypyridyl catalyst can act as a more effective catalyst than the commonly utilized [Co(bpy)3]2+. This study may offer a new paradigm for constructing simple and noble‐metal‐free catalysts for photocatalytic hydrogen production. 相似文献
15.
W. Mark Barnett Russell G. Baughman Paula M. Secondo Charles J. Hermansen 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(9):o565-o567
The crystal structures of the title compounds, alternatively called 2,2′‐(2,2′‐biimidazole‐1,1′‐diyl)diacetohydrazide monohydrate, C10H14N8O2·H2O, (I), and 3,3′‐(2,2′‐biimidazole‐1,1′‐diyl)dipropionohydrazide, C12H18N8O2, (II), respectively, have been determined. The molecules consist of half‐molecule asymmetric units related by a twofold rotation in (I) and by a center of inversion in (II). The imidazole rings of both molecules crystallize in a nearly coplanar fashion [dihedral angles of 5.91 (3) and 0.0 (1)° for (I) and (II), respectively]. Both planar hydrazinocarbonylalkyl substituents are essentially planar and assume the E orientation. 相似文献
16.
S. Renganayaki E. Subramanian S. Shanmuga Sundara Raj Hoong‐Kun Fun 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(3):349-350
The aromatic ring of the cinnamic moiety in N‐benzyl‐2′‐iodocinnamanilide, C22H18INO, (I), and N‐benzyl‐2′‐iodo‐4′‐methyl‐2‐phenylcinnamanilide, C29H24INO, (II), makes a dihedral angle with the iodophenyl ring of 72.1 (2) and 81.0 (2)° in (I) and (II), respectively. In (I), molecules exist as discrete components, while in (II), they form infinite chains along the b axis, through I?O non‐bonded interactions. 相似文献
17.
Synthesis of Amphiphilic RuII Heteroleptic Complexes Based on Benzo[1,2‐b:4,5‐b′]dithiophene: Relevance of the Half‐Sandwich Complex Intermediate and Solvent Compatibility 下载免费PDF全文
Dr. Maxence Urbani María Medel Dr. Sangeeta Amit Kumar Dr. Mine Ince Prof. Ashok N. Bhaskarwar Dr. David González‐Rodríguez Michael Grätzel Prof. Mohammad Khaja Nazeeruddin Prof. Tomás Torres 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(45):16252-16265
The detailed synthesis and characterization of four ruthenium(II) complexes [RuLL′(NCS)2] is reported, in which L represents a 2,2′‐bipyridine ligand functionalized at the 4,4′ positions with benzo[1,2‐b:4,5‐b′]dithiophene derivatives (BDT) and L′ is 2,2′‐bipyridine‐4,4′‐dicarboxylic acid unit (dcbpy) (NCS=isothiocyanate). The reaction conditions were adapted and optimized for the preparation of these amphiphilic complexes with a strong lipophilic character. The photovoltaic performances of these complexes were tested in TiO2 dye‐sensitized solar cell (DSSC) achieving efficiencies in the range of 3–4.5 % under simulated one sun illumination (AM1.5G). 相似文献
18.
N,N′‐Dioxide/Nickel(II)‐Catalyzed Asymmetric Inverse‐Electron‐Demand Hetero‐Diels–Alder Reaction of β,γ‐Unsaturated α‐Ketoesters with Enecarbamates 下载免费PDF全文
Yuhang Zhou Yin Zhu Dr. Lili Lin Yulong Zhang Jianfeng Zheng Prof. Dr. Xiaohua Liu Prof. Dr. Xiaoming Feng 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(50):16753-16758
N,N′‐Dioxide/nickel(II) complexes have been developed to catalyze the inverse‐electron‐demand hetero‐Diels–Alder reaction of β,γ‐unsaturated α‐ketoesters with acyclic enecarbamates. After detailed screening of the reaction parameters, mild optimized reaction conditions were established, affording 3,4‐dihydro‐2H‐pyranamines in up to 99 % yield, 99 % ee and more than 95:5 d.r. The catalytic system was also efficient for β‐substituted acyclic enecarbamates, affording more challenging 2,3,4‐trisubstituted 3,4‐dihydro‐2H‐pyranamine with three contiguous stereogenic centers in excellent yields, diastereoselectivities, and enantioselectivities. The reaction could be scaled up to a gram scale with no deterioration of either enantioselectivity or yield. Based on these experiments and on previous reports, a possible transition state was proposed. 相似文献
19.
Ying Fu Yin‐Xia He Hong‐Xia Hou Wen‐Bo Zhu Hu‐Lin Li Chao Wu Fang‐Yan Xian 《Acta Crystallographica. Section C, Structural Chemistry》2013,69(3):282-284
2,2′‐Anhydro‐1‐(3′,5′‐di‐O‐acetyl‐β‐D‐arabinofuranosyl)uracil, C13H14N2O7, was obtained by refluxing 2′,3′‐O‐(methoxymethylene)uridine in acetic anhydride. The structure exhibits a nearly perfect C4′‐endo (4E) conformation. The best four‐atom plane of the five‐membered furanose ring is O—C—C—C, involving the C atoms of the fused five‐membered oxazolidine ring, and the torsion angle is only −0.4 (2)°. The oxazolidine ring is essentially coplanar with the six‐membered uracil ring [r.m.s. deviation = 0.012 (5) Å and dihedral angle = −3.2 (3)°]. The conformation at the exocyclic C—C bond is gauche–trans which is stabilized by various C—H...π and C—O...π interactions. 相似文献
20.
Lewis M. Broomfield Manfred Bochmann Joseph A. Wright 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(3):m79-m82
The title phosphine oxide–phosphine, 0.43C17H16NOP·0.57C17H16NP, (I)/(II), was obtained as a 0.861 (6):1.139 (6) cocrystallized mixture. Hydrogen bonding between the two constituents leads to the formation of 2:2 solid‐state assemblies. Instead of forming the expected simple N,P‐chelated system via loss of the N‐bound H atom, reaction of 2‐(diphenylphosphinomethyl)pyrrole, (II), with TiCl4 leads to the formation of the title titanium(IV) complex, [TiCl4(C17H16NP)], (IV), containing a rearranged neutral ligand in which the N‐bound H atom moves to one of the pyrrole C atoms, giving a partially unsaturated ring. 相似文献