Active Esters as Pseudostoppers for Slippage Synthesis of [2]Pseudorotaxane Building Blocks: A Straightforward Route to Multi-Interlocked Molecular Machines

2016 ◽  
Vol 22 (26) ◽  
pp. 8835-8847 ◽  
Author(s):  
Thibaut Legigan ◽  
Benjamin Riss-Yaw ◽  
Caroline Clavel ◽  
Frédéric Coutrot
Keyword(s):  
Molecular Machines ◽  
Building Blocks ◽  
Active Esters

scholarly journals Nickel-Catalyzed Site- and Stereoselective Reductive Alkylalkynylation of Alkynes

2020 ◽  
Author(s):  
Yi Jiang ◽  
Jiaoting Pan ◽  
Tao Yang ◽  
Joel Jun Han Lim ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Functional Groups ◽  
Multicomponent Reaction ◽  
Alkyl Group ◽  
Crucial Role ◽  
Building Blocks ◽  
Radical Addition ◽  
Active Esters ◽  
Redox Active

Development of a catalytic multicomponent reaction by orthogonal activation of readily available substrates for the streamlined difunctionalization of alkynes is a compelling objective in organic chemistry. Alkyne carboalkynylation, in particular, offers a direct entry to valuable 1,3-enynes with different substitution patterns. Here, we show that the synthesis of stereodefined 1,3-enynes featuring a trisubstituted olefin is achieved by merging alkynes, alkynyl bromides and redox-active <i>N</i>-(acyloxy)phthalimides through nickel-catalyzed reductive alkylalkynylation. Products are generated in up to 89% yield as single regio- and <i>E</i> isomers. Transformations are tolerant of diverse functional groups and the resulting 1,3-enynes are amenable to further elaboration to synthetically useful building blocks. With olefin-tethered <i>N</i>-(acyloxy)phthalimides, a cascade radical addition/cyclization/alkynylation process can be implemented to obtain 1,5-enynes. The present study underscores the crucial role of redox-active esters as superior alkyl group donors compared to haloalkanes in reductive alkyne dicarbofunctionalizations.

scholarly journals Site- and Stereoselective Reductive Alkylalkynylation of Alkynes using Redox-Active Esters as Alkyl Group Donors

2020 ◽  
Author(s):  
Yi Jiang ◽  
Jiaoting Pan ◽  
Tao Yang ◽  
Joel Jun Han Lim ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Functional Groups ◽  
Multicomponent Reaction ◽  
Alkyl Group ◽  
Crucial Role ◽  
Building Blocks ◽  
Radical Addition ◽  
Active Esters ◽  
Redox Active

Development of a catalytic multicomponent reaction by orthogonal activation of readily available substrates for the streamlined difunctionalization of alkynes is a compelling objective in organic chemistry. Alkyne carboalkynylation, in particular, offers a direct entry to valuable 1,3-enynes with different substitution patterns. Here, we show that the synthesis of stereodefined 1,3-enynes featuring a trisubstituted olefin is achieved by merging alkynes, alkynyl bromides and redox-active <i>N</i>-(acyloxy)phthalimides through nickel-catalyzed reductive alkylalkynylation. Products are generated in up to 89% yield as single regio- and <i>E</i> isomers. Transformations are tolerant of diverse functional groups and the resulting 1,3-enynes are amenable to further elaboration to synthetically useful building blocks. With olefin-tethered <i>N</i>-(acyloxy)phthalimides, a cascade radical addition/cyclization/alkynylation process can be implemented to obtain 1,5-enynes. The present study underscores the crucial role of redox-active esters as superior alkyl group donors compared to haloalkanes in reductive alkyne dicarbofunctionalizations.

scholarly journals Tetrathiafulvalene – a redox-switchable building block to control motion in mechanically interlocked molecules

2018 ◽  
Vol 14 ◽  
pp. 2163-2185 ◽  
Author(s):  
Hendrik V Schröder ◽  
Christoph A Schalley
Keyword(s):  
Molecular Motion ◽  
Functional Unit ◽  
Molecular Machines ◽  
Building Blocks ◽  
Interlocked Molecules ◽  
The Past ◽  
Research Challenge ◽  
And Control ◽  
Redox Switches ◽  
Selection Of

With the rise of artificial molecular machines, control of motion on the nanoscale has become a major contemporary research challenge. Tetrathiafulvalenes (TTFs) are one of the most versatile and widely used molecular redox switches to generate and control molecular motion. TTF can easily be implemented as functional unit into molecular and supramolecular structures and can be reversibly oxidized to a stable radical cation or dication. For over 20 years, TTFs have been key building blocks for the construction of redox-switchable mechanically interlocked molecules (MIMs) and their electrochemical operation has been thoroughly investigated. In this review, we provide an introduction into the field of TTF-based MIMs and their applications. A brief historical overview and a selection of important examples from the past until now are given. Furthermore, we will highlight our latest research on TTF-based rotaxanes.

scholarly journals A platinum(II) molecular hinge with motions visualized by phosphorescence changes

2019 ◽  
Vol 116 (28) ◽  
pp. 13856-13861 ◽  
Author(s):  
Yeye Ai ◽  
Michael Ho-Yeung Chan ◽  
Alan Kwun-Wa Chan ◽  
Maggie Ng ◽  
Yongguang Li ◽  
...  
Keyword(s):  
Green Emission ◽  
Molecular Machines ◽  
Building Blocks ◽  
Behavior Changes ◽  
Temperature Changes ◽  
Innovative Methods ◽  
Conformation Changes ◽  
Square Planar ◽  
Reversible Processes ◽  
Molecular Hinge

With the rapidly growing exploration of artificial molecular machines and their applications, there is a strong demand to develop molecular machines that can have their motional states and configuration/conformation changes detectable by more sensitive and innovative methods. A visual artificial molecular hinge with phosphorescence behavior changes is designed and synthesized using square-planar cyclometalated platinum(II) complex and rigid aromatic alkynyl groups as the building blocks to construct the wings/flaps and axis, respectively. The molecular motions of this single molecular hinge and its reversible processes can be powered by both solvent and temperature changes. The rotary motion can be conveniently observed by the visual phosphorescence changes from deep-red to green emission in real time.

scholarly journals Nickel-Catalyzed Site- and Stereoselective Reductive Alkylalkynylation of Alkynes

2020 ◽  
Author(s):  
Yi Jiang ◽  
Jiaoting Pan ◽  
Tao Yang ◽  
Joel Jun Han Lim ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Organic Chemistry ◽  
Functional Groups ◽  
Multicomponent Reaction ◽  
Alkyl Group ◽  
Crucial Role ◽  
Building Blocks ◽  
Radical Addition ◽  
Active Esters ◽  
Redox Active

Development of a catalytic multicomponent reaction by orthogonal activation of readily available substrates for the streamlined difunctionalization of alkynes is a compelling objective in organic chemistry. Alkyne carboalkynylation, in particular, offers a direct entry to valuable 1,3-enynes with different substitution patterns. Here, we show that the synthesis of stereodefined 1,3-enynes featuring a trisubstituted olefin is achieved by merging alkynes, alkynyl bromides and redox-active <i>N</i>-(acyloxy)phthalimides through nickel-catalyzed reductive alkylalkynylation. Products are generated in up to 89% yield as single regio- and <i>E</i> isomers. Transformations are tolerant of diverse functional groups and the resulting 1,3-enynes are amenable to further elaboration to synthetically useful building blocks. With olefin-tethered <i>N</i>-(acyloxy)phthalimides, a cascade radical addition/cyclization/alkynylation process can be implemented to obtain 1,5-enynes. The present study underscores the crucial role of redox-active esters as superior alkyl group donors compared to haloalkanes in reductive alkyne dicarbofunctionalizations.

Organic Cages as Building Blocks for Mechanically Interlocked Molecules: Towards Molecular Machines

ChemPlusChem ◽  
2020 ◽  
Vol 85 (6) ◽  
pp. 1145-1155
Author(s):  
Sonia La Cognata ◽  
Ana Miljkovic ◽  
Riccardo Mobili ◽  
Greta Bergamaschi ◽  
Valeria Amendola
Keyword(s):  
Molecular Machines ◽  
Building Blocks ◽  
Interlocked Molecules

Thermodynamic problems in structural molecular biology

2007 ◽  
Vol 79 (8) ◽  
pp. 1445-1462 ◽  
Author(s):  
Peter L. Privalov
Keyword(s):  
Structural Organization ◽  
Essential Feature ◽  
Molecular Machines ◽  
Building Blocks ◽  
Biological Macromolecules ◽  
Biological Processes ◽  
Native Conformation ◽  
Genetically Determined ◽  
Order Complexes ◽  
High Degree

The most essential feature of living biological systems is their high degree of structural organization. The key role is played by two linear heteropolymers, the proteins and nucleic acids. Under environmental conditions close to physiological, these biopolymers are folded into unique native conformations, genetically determined by the arrangement of their standard building blocks. In their native conformation, biological macromolecules recognize their partners and associate with them, forming specific, higher-order complexes, the "molecular machines". Folding of biopolymers into their native conformation and their association with partners is in principle a reversible, thermodynamically driven process. Investigation of the thermodynamics of these basic biological processes has prime importance for understanding the mechanisms of forming these supra-macromolecular constructions and their functioning.

Editorial: "ACTIVE BIOMIMETIC SYSTEMS: FORCE GENERATION AND CARGO TRANSPORT BY MOLECULAR MACHINES"

2009 ◽  
Vol 04 (01n02) ◽  
pp. 1-4 ◽  
Author(s):  
REINHARD LIPOWSKY ◽  
ANGELO VALLERIANI
Keyword(s):  
Molecular Machines ◽  
Building Blocks ◽  
Mechanical Work ◽  
Chemical Energy ◽  
Force Generation ◽  
Eukaryotic Cells ◽  
Special Issue ◽  
Nucleotide Hydrolysis ◽  
Biomimetic Systems ◽  
Cargo Transport

This special issue of Biophysical Reviews and Letters describes recent advances in the area of active biomimetic systems, which are inspired by the cytoskeletal architecture found in all eukaryotic cells. The main building blocks of these systems are provided by two types of cytoskeletal filaments, F-actin and microtubules, as well as molecular stepping motors such as kinesins and myosins. All of these building blocks represent molecular machines: They are coupled to nucleotide hydrolysis and are able to convert the chemical energy released from this process into mechanical work. Bundles of filaments and teams of stepping motors generate strong pushing forces and perform long-ranged cargo transport.

Photochemical Evolution of Interstellar/Precometary Organic Material

1997 ◽  
Vol 161 ◽  
pp. 23-47 ◽  
Author(s):  
Louis J. Allamandola ◽  
Max P. Bernstein ◽  
Scott A. Sandford
Keyword(s):  
Origin Of Life ◽  
Building Blocks ◽  
Complex Species ◽  
Infrared Observations ◽  
Interstellar Ice ◽  
Polycyclic Aromatic ◽  
Ultraviolet Photolysis ◽  
The Origin Of Life ◽  
Simple Molecules ◽  
Complex Organic

AbstractInfrared observations, combined with realistic laboratory simulations, have revolutionized our understanding of interstellar ice and dust, the building blocks of comets. Since comets are thought to be a major source of the volatiles on the primative earth, their organic inventory is of central importance to questions concerning the origin of life. Ices in molecular clouds contain the very simple molecules H2O, CH3OH, CO, CO2, CH4, H2, and probably some NH3and H2CO, as well as more complex species including nitriles, ketones, and esters. The evidence for these, as well as carbonrich materials such as polycyclic aromatic hydrocarbons (PAHs), microdiamonds, and amorphous carbon is briefly reviewed. This is followed by a detailed summary of interstellar/precometary ice photochemical evolution based on laboratory studies of realistic polar ice analogs. Ultraviolet photolysis of these ices produces H2, H2CO, CO2, CO, CH4, HCO, and the moderately complex organic molecules: CH3CH2OH (ethanol), HC(= O)NH2(formamide), CH3C(= O)NH2(acetamide), R-CN (nitriles), and hexamethylenetetramine (HMT, C6H12N4), as well as more complex species including polyoxymethylene and related species (POMs), amides, and ketones. The ready formation of these organic species from simple starting mixtures, the ice chemistry that ensues when these ices are mildly warmed, plus the observation that the more complex refractory photoproducts show lipid-like behavior and readily self organize into droplets upon exposure to liquid water suggest that comets may have played an important role in the origin of life.

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