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1.
Towards Molecular Construction Platforms: Synthesis of a Metallotricyclic Spirane Based on Bis(2,2′:6′,2“‐Terpyridine)RuII Connectivity
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Dr. Ting‐Zheng Xie Kai Guo Mingjun Huang Dr. Xiaocun Lu Sheng‐Yun Liao Rajarshi Sarkar Dr. Charles N. Moorefield Prof. Stephen Z. D. Cheng Prof. Chrys Wesdemiotis Prof. George R. Newkome 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(36):11291-11294
The design and construction of the first multicomponent stepwise assembly of a <tpy‐RuII‐tpy>‐based (tpy=terpyridine), three‐dimensional, propeller‐shaped trismacrocycle, 8 , are reported. Key steps in the synthesis involve the preparation of a hexaterpyridinyl triptycene and its reaction with dimeric, 60°‐directional, bisterpyridine‐RuII building blocks. Characterization includes ESI‐ and ESI‐TWIM‐MS and TEM, along with 1D and 2D 1H NMR spectroscopy. 相似文献
2.
《Journal of polymer science. Part A, Polymer chemistry》2018,56(8):931-937
The synthesis of ethynylene triptycene‐based copolymers with various aromatic spacers ( 3a–d ) is reported using the palladium‐catalyzed Sonogashira cross‐coupling reaction. The alkyne groups of 3a–d were oxidized into their respective α‐diketone copolymers 4a–d . Formation of 3,4a–d was confirmed by several characterization techniques, such as, gel permeation chromatography (GPC), 1H and 13C nuclear magnetic resonance (NMR), FT‐infrared (FTIR), UV–vis absorption, and emission spectroscopies. It was found that the nature of the aromatic spacer influences the emission properties of the target α‐diketone triptycene copolymers, causing either a red or blue‐shift with respect to that of their ethynylene triptycene copolymer synthons. Copolymers 4a–c with fluorene spacers reveal emission in the range of 440–475 nm, thus, qualifying them to act as blue emitters. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 931–937 相似文献
3.
Penghao Li Peng Li Matthew R. Ryder Zhichang Liu Charlotte L. Stern Omar K. Farha J. Fraser Stoddart 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(6):1678-1683
We describe an example of “interpenetration isomerism” in three‐dimensional hydrogen‐bonded organic frameworks. By exploiting the crystallization conditions for a peripherally extended triptycene H6PET, we can modulate the interpenetration of the assembled frameworks, yielding a two‐fold interpenetrated structure PETHOF‐ 1 and a five‐fold interpenetrated structure PETHOF‐ 2 as interpenetration isomers. In PETHOF‐ 1 , two individual nets are related by inversion symmetry and form an interwoven topology with a large guest‐accessible volume of about 80 %. In PETHOF‐ 2 , five individual nets are related by translational symmetry and are stacked in an alternating fashion. The activated materials show permanent porosity with Brunauer‐Emmett‐Teller surface areas exceeding 1100 m2 g?1. Synthetic control over the framework interpenetration could serve as a new strategy to construct complex supramolecular architectures from simple organic building blocks. 相似文献
4.
Yuanzhe Zhang Bo Li Shih‐Yuan Liu 《Angewandte Chemie (International ed. in English)》2020,59(37):15928-15932
The first trans‐selective cyanoboration reaction of an alkyne, specifically a 1,3‐enyne, is described. The reported palladium‐catalyzed cyanoboration of 1,3‐enynes is site‐, regio‐, and diastereoselective, and is uniquely enabled by the 1,4‐azaborine‐based Senphos ligand structure. Tetra‐substituted alkenyl nitriles are obtained providing useful boron‐dienenitrile building blocks that can be further functionalized. The utility of our method has been demonstrated with the synthesis of Satigrel, an anti‐platelet aggregating agent. 相似文献
5.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(43):13536-13540
Selective functionalization at the meta position of arenes remains a significant challenge. In this work, we demonstrate that a single anionic bipyridine ligand bearing a remote sulfonate group enables selective iridium‐catalyzed borylation of a range of common amine‐containing aromatic molecules at the arene meta position. We propose that this selectivity is the result of a key hydrogen bonding interaction between the substrate and catalyst. The scope of this meta‐selective borylation is demonstrated on amides derived from benzylamines, phenethylamines and phenylpropylamines; amine‐containing building blocks of great utility in many applications. 相似文献
6.
Synthesis of Di‐, Tri‐, and Tetrasubstituted Oxetanes by Rhodium‐Catalyzed OH Insertion and CC Bond‐Forming Cyclization
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Owen A. Davis Dr. James A. Bull 《Angewandte Chemie (International ed. in English)》2014,53(51):14230-14234
Oxetanes offer exciting potential as structural motifs and intermediates in drug discovery and materials science. Here an efficient strategy for the synthesis of oxetane rings incorporating pendant functional groups is described. A wide variety of oxetane 2,2‐dicarboxylates were accessed in high yields, including functionalized 3‐/4‐aryl‐ and alkyl‐substituted oxetanes and fused oxetane bicycles. Enantioenriched alcohols provided enantioenriched oxetanes with complete retention of configuration. The oxetane products were further derivatized, while the ring was maintained intact, thus highlighting their potential as building blocks for medicinal chemistry. 相似文献
7.
Dr. Marcus Papmeyer Clément A. Vuilleumier Dr. Giovanni M. Pavan Dr. Konstantin O. Zhurov Prof. Kay Severin 《Angewandte Chemie (International ed. in English)》2016,55(5):1685-1689
A facile and flexible method for the synthesis of a new AAA–DDD triple hydrogen‐bonding motif is described. Polytopic supramolecular building blocks with precisely oriented AAA and DDD groups are thus accessible in few steps. These building blocks were used for the assembly of large macrocycles featuring four AAA–DDD interactions and a macrobicyclic complex with a total of six AAA–DDD interactions. 相似文献
8.
Sequence‐Defined Oligomers from Hydroxyproline Building Blocks for Parallel Synthesis Applications
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Dr. Rosemary L. Kanasty Prof. Arturo J. Vegas Luke M. Ceo Dr. Martin Maier Dr. Klaus Charisse Dr. Jayaprakash K. Nair Prof. Robert Langer Prof. Daniel G. Anderson 《Angewandte Chemie (International ed. in English)》2016,55(33):9529-9533
The functionality of natural biopolymers has inspired significant effort to develop sequence‐defined synthetic polymers for applications including molecular recognition, self‐assembly, and catalysis. Conjugation of synthetic materials to biomacromolecules has played an increasingly important role in drug delivery and biomaterials. We developed a controlled synthesis of novel oligomers from hydroxyproline‐based building blocks and conjugated these materials to siRNA. Hydroxyproline‐based monomers enable the incorporation of broad structural diversity into defined polymer chains. Using a perfluorocarbon purification handle, we were able to purify diverse oligomers through a single solid‐phase extraction method. The efficiency of synthesis was demonstrated by building 14 unique trimers and 4 hexamers from 6 diverse building blocks. We then adapted this method to the parallel synthesis of hundreds of materials in 96‐well plates. This strategy provides a platform for the screening of libraries of modified biomolecules. 相似文献
9.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2018,130(8):2266-2269
Condensation of 1,8,13‐tris(mercaptomethyl)triptycene and tris(bromomethyl)methane yields an in,in‐cyclophane with two inwardly directed methine groups. Based on X‐ray analysis and DFT and MP2 calculations, the hydrogen–hydrogen non‐bonded contact distance is estimated to be 1.50–1.53 Å. Furthermore, the two in‐hydrogen atoms show obvious spin–spin coupling with J=2.0 Hz. 相似文献
10.
An Exceptionally Close,Non‐Bonded Hydrogen–Hydrogen Contact with Strong Through‐Space Spin–Spin Coupling
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Yonglong Xiao Prof. Joel T. Mague Prof. Robert A. Pascal Jr. 《Angewandte Chemie (International ed. in English)》2018,57(8):2244-2247
Condensation of 1,8,13‐tris(mercaptomethyl)triptycene and tris(bromomethyl)methane yields an in,in‐cyclophane with two inwardly directed methine groups. Based on X‐ray analysis and DFT and MP2 calculations, the hydrogen–hydrogen non‐bonded contact distance is estimated to be 1.50–1.53 Å. Furthermore, the two in‐hydrogen atoms show obvious spin–spin coupling with J=2.0 Hz. 相似文献
11.
Selective Production of Renewable para‐Xylene by Tungsten Carbide Catalyzed Atom‐Economic Cascade Reactions
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Tao Dai Dr. Changzhi Li Dr. Lin Li Prof. Zongbao Kent Zhao Dr. Bo Zhang Prof. Yu Cong Prof. Aiqin Wang 《Angewandte Chemie (International ed. in English)》2018,57(7):1808-1812
Tungsten carbide was employed as the catalyst in an atom‐economic and renewable synthesis of para‐xylene with excellent selectivity and yield from 4‐methyl‐3‐cyclohexene‐1‐carbonylaldehyde (4‐MCHCA). This intermediate is the product of the Diels–Alder reaction between the two readily available bio‐based building blocks acrolein and isoprene. Our results suggest that 4‐MCHCA undergoes a novel dehydroaromatization–hydrodeoxygenation cascade process by intramolecular hydrogen transfer that does not involve an external hydrogen source, and that the hydrodeoxygenation occurs through the direct dissociation of the C=O bond on the W2C surface. Notably, this process is readily applicable to the synthesis of various (multi)methylated arenes from bio‐based building blocks, thus potentially providing a petroleum‐independent solution to valuable aromatic compounds. 相似文献
12.
Van T. Tran Zi‐Qi Li Timothy J. Gallagher Joseph Derosa Peng Liu Keary M. Engle 《Angewandte Chemie (International ed. in English)》2020,59(18):7029-7034
Allylation and conjunctive cross‐coupling represent two useful, yet largely distinct, reactivity paradigms in catalysis. The union of these two processes would offer exciting possibilities in organic synthesis but remains largely unknown. Herein, we report the use of allyl electrophiles in nickel‐catalyzed conjunctive cross‐coupling with a non‐conjugated alkene and dimethylzinc. The transformation is enabled by weakly coordinating, monodentate aza‐heterocycle directing groups that are useful building blocks in synthesis, including saccharin, pyridones, pyrazoles, and triazoles. The reaction occurs under mild conditions and is compatible with a wide range of allyl electrophiles. High chemoselectivity through substrate directivity is demonstrated by the facile reactivity of the β‐γ alkene of the starting material, whereas the ?‐ζ alkene of the product is preserved. The generality of this approach is further illustrated through the development of an analogous method with alkyne substrates. Mechanistic studies reveal the importance of the dissociation of the weakly coordinating directing group to allow the allyl moiety to bind and facilitate C(sp3)?C(sp3) reductive elimination. 相似文献
13.
Leen Billiet David Fournier Filip Du Prez 《Journal of polymer science. Part A, Polymer chemistry》2008,46(19):6552-6564
Aliphatic polyesters bearing pendant alkyne groups were successfully prepared by step‐growth polymerization of different building blocks such as adipic acid and succinic acid in combination with an acetylene‐based diol, 2‐methyl‐2‐propargyl‐1,3‐propanediol, besides 1,4‐butanediol and ethylene glycol. It was demonstrated that the alkyne groups survive the high reaction temperatures (200 °C) in the presence of a radical inhibitor. The alkyne loading has been tuned by the ratio of the different monomers used, up to 25 mol % of alkyne groups. Subsequently, the alkyne groups have been reacted with azides by the copper‐catalyzed Huisgen 1,3‐dipolar cycloaddition reaction, a popular type of “click” chemistry. “Click” reactions have been performed quantitatively in the presence of benzyl azide and azide‐terminated poly(ethylene glycol), yielding brush copolymers in the latter case. Kinetic investigations about this click reaction have been performed by means of on‐line Fourier transform mid‐infrared spectroscopy, which was reported for the first time in the field of the click chemistry research. A whole range of functionalized polyesters, based on poly(ethylene succinate) and poly(butylene adipate), is available, the properties of which can be tailored by choosing the appropriate azide compound. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6552–6564, 2008 相似文献
14.
Rational Design for Complementary Donor–Acceptor Recognition Pairs Using Self‐Complementary Hydrogen Bonds
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Amrita Sikder Boyli Ghosh Saptarshi Chakraborty Dr. Ankan Paul Dr. Suhrit Ghosh 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(6):1908-1913
An adaptable and efficient molecular recognition pair has been established by taking advantage of the complementary nature of donor–acceptor interactions together with the strength of hydrogen bonds. Such distinct molecular recognition propagates in orthogonal directions to effect extended alternating co‐assembly of two different appended molecular entities. The dimensions of the assembled structures can be tuned by stoichiometric imbalance between the donor and acceptor building blocks. The morphology of the self‐assembled material can be correlated with the ratio of the two building blocks. 相似文献
15.
Kerstin T. Wiss Patrick Theato 《Journal of polymer science. Part A, Polymer chemistry》2010,48(21):4758-4767
The synthesis of block copolymers via polymer conjugation of well‐defined building blocks offers excellent control over the structures obtained, but often several coupling strategies need to be explored to find an efficient one depending on the building blocks. To facilitate the synthesis of polymers with adjustable functional end‐groups for polymer conjugation, we report on the combination of activated ester chemistry with RAFT polymerization using a chain transfer agent (CTA) with a pentafluorophenyl ester (PFP‐CTA), which allows for flexible functionalization of either the CTA prior to polymerization or the obtained polymer after polymerization. Different polymethacrylates, namely PMMA, P(t‐BuMA) and PDEGMEMA, were synthesized with an alkyne‐CTA obtained from the aminolysis of the PFP‐CTA with propargylamine, and the successful incorporation of the alkyne moiety could be shown via 1H and 13C NMR spectroscopy and MALDI TOF MS. Further, the reactive α‐end‐groups of polymers synthesized using the unmodified PFP‐CTA could be converted into azide and alkyne end‐groups after polymerization, and the high functionalization efficiencies could be demonstrated via successful coupling of the resulting polymers via CuAAC. Thus, the PFP‐CTA allows for high combinatory flexibility in polymer synthesis facilitating polymer conjugation as useful method for the synthesis of block copolymers. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
16.
Stefanie A. Sydlik Paula A. Delgado Sotaro Inomata Brett VanVeller Yong Yang Timothy M. Swager Kenneth B. Wagener 《Journal of polymer science. Part A, Polymer chemistry》2013,51(8):1695-1706
Several new triptycene‐containing polyetherolefins were synthesized via acyclic diene metathesis (ADMET) polymerization. The well‐established mechanism, high selectivity and specificity, mild reaction conditions, and well‐defined end‐groups make the ADMET polymerization a good choice for studying systematic variations in polymer structure. Two types of triptycene‐based monomer with varying connectivities were used in the synthesis of homopolymers, block copolymers, and random copolymers. In this way, the influence of the triptycene architecture and concentration in the polymer backbone on the thermal behavior of the polymers was studied. Inclusion of increasing amounts of triptycene were found to increase the glass transition temperature, from ?44 °C in polyoctenamer to 59 °C in one of the hydrogenated triptycene homopolymers ( H‐PT2 ). Varying the amounts and orientations of triptycene was found to increase the stiffness ( H‐PT1 ), toughness ( PT11‐b‐PO1 ) and ductility ( PT11‐ran‐PO3 ) of the polymer at room temperature. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
17.
Regulating Molecular Recognition with C‐Shaped Strips Attained by Chirality‐Assisted Synthesis
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Dr. Xiaoxi Liu Zackariah J. Weinert Mona Sharafi Dr. Chenyi Liao Prof. Jianing Li Prof. Severin T. Schneebeli 《Angewandte Chemie (International ed. in English)》2015,54(43):12772-12776
Chirality‐assisted synthesis (CAS) is a general approach to control the shapes of large molecular strips. CAS is based on enantiomerically pure building blocks that are designed to strictly couple in a single geometric orientation. Fully shape‐persistent structures can thus be created, even in the form of linear chains. With CAS, selective recognition between large host and guest molecules can reliably be designed de novo. To demonstrate this concept, three C‐shaped strips that can embrace a pillar[5]arene macrocycle were synthesized. The pillar[5]arene bound to the strips was a better host for electron‐deficient guests than the free macrocycle. Experimental and computational evidence is provided for these unique cooperative interactions to illustrate how CAS could open the door towards the precise positioning of functional groups for regulated supramolecular recognition and catalysis. 相似文献
18.
Dr. Monique J. Jacobs Dr. Guenter Schneider Dr. Kerstin G. Blank 《Angewandte Chemie (International ed. in English)》2016,55(8):2899-2902
Mechanophores, that is, molecules that show a defined response to force, are crucial building blocks of mechanoresponsive materials. The possibility of mechanically induced cycloreversion for a series of triazoles formed via strain‐promoted azide–alkyne cycloaddition reactions was investigated by density functional theory calculations, and these triazoles were compared to the 1,4‐ and 1,5‐regioisomers formed in the reaction of an azide with a terminal alkyne. We show that cycloreversion is in principal possible and that the pulling geometry is the most important parameter that determines the probability of cycloreversion. We further compared triazole stability to the mechanical stability of polymers that are frequently used as force transducers in mechanochemical experiments and identified DIBAC (azadibenzylcyclooctyne) as a promising mechanophore for future applications. 相似文献
19.
Platinum(0) Complexes with Amino‐Substituted Alkynes: Novel Organometallic Building Blocks for Supramolecular Architectures and “Crystal Engineering” Homoleptic Bis(alkyne)platinum(0) compounds containing either NH2‐ or NH2‐/OH‐substituents are formed by reaction of Pt(cod)2 with alkynes as stable compounds. They can be used as variable building blocks for supramolecular networks. The crystal structure analyses of Bis(2‐amino‐2,5dimethyl‐5‐hydroxy‐hex‐3‐yne)platinum(0) ( 1 ) and of Bis(1(3‐amino‐3‐methyl‐but‐1‐inyl)‐cyclohexane‐1‐ol)platinum(0) ( 2 ) exhibit that the low‐valent Pt atom is tetrahedrally surrounded by the four sp‐hybridizated carbonatoms of the alkynes. Despite the fact that the bond lengths and ‐angles of the PtC4 units are equal, the supramolecular structures are different. While in 1 polymer strands are formed in which the bis(alkyne)‐Pt0 units are connected by (OH)2(NH2)2‐ tetrahedrons, 2 yields only a dimer containing a network of four OH‐ and two NH2‐groups. Platinum(0) complexes with cationic alkynes bearing ammonium substituents can be isolated as thermal stable compounds. The X‐ray structures of [Cl( FH +)Pt(cod)]4 ( 8 ) reveals that four molecular units form a cube with both four NH3+ groups and Cl– at the corners connected by hydrogen bridges. In the bis(alkyne)Pt0 complex [Cl1.5( FH +)1.5( F )0.5Pt] ( 9 ) only 1,33 of two NH2 groups are protonated and a hydrogen bridged network connects four bis(alkyne)Pt0 units (cod: cycloocta‐1.5‐diene, F : 1‐(trimethylsilylethinyl)‐1‐amino‐cyclohexane). 相似文献
20.
Dr. Daniel Beaudoin Dr. Frank Rominger Prof. Dr. Michael Mastalerz 《Angewandte Chemie (International ed. in English)》2016,55(50):15599-15603
The strategy of chirality‐assisted synthesis, which makes use of enantiomerically pure building blocks that are designed to associate in a single geometric orientation, was applied to synthesize an octameric hydrogen‐bonded capsule with a cavity volume of 2300 Å3. This cube‐shaped capsule forms even host–guest complexes with tetraalkylammonium ions, and accommodates the large tetrahexadecylammonium cation in its cavity. The use of an enantiopure building block was shown to be highly beneficial for capsule formation, whereas its racemate also generates a large amount of ill‐defined aggregates in solution and crystallizes as a hydrogen‐bonded network. 相似文献