NDLI: Template-directed synthesis of kinetically and thermodynamically stable molecular necklace using ring closing metathesis

Content Provider	Royal Society of Chemistry (RSC)
Author	Dasgupta, Suvankar Wu, Jishan
Copyright Year	2011
Abstract	We report the template-directed synthesis of a well-defined, kinetically stable [5]molecular necklace with dialkylammonium ion (R2NH2+) as recognition site and DB24C8 as macrocycle. A thread containing four dialkylammonium ions with olefin at both ends was first synthesized and then subjected to threading with an excess amount of DB24C8 to form pseudo[5]rotaxane, which in situ undergoes ring closing metathesis at the termini with second generation Grubbs catalyst to yield the desired [5]molecular necklace. The successful synthesis of [5]molecular necklace is mainly attributed to the self-assembly and dynamic covalent chemistry which allows the formation of thermodynamically most stable product. The self-assembly of the DB24C8 ring onto the recognition site known as templating effect was driven by noncovalent stabilizing interactions like [N+–H⋯O], [C–H⋯O] hydrogen bonds as well as [π⋯π] interactions which is facilitated in non-polar solvents. The reversible nature of olefin metathesis reaction makes it suitable for dynamic covalent chemistry since proof-reading and error-checking operates until it generates thermodynamically the most stable interlocked molecule. Riding on the success of [5]molecular necklace, we went a step further and attempted to synthesize [7]molecular necklace using the same protocol. This led to the synthesis of another thread with olefin at both ends but having six dibenzylammonium ions along the thread. However, the extremely poor solubility of this thread containing six secondary ammonium ions limits the self-assembly process even after we replaced the typical PF6− counter anion with a more lipophilic BPh4− anion. Although the poor solubility of the thread remains the bottleneck for making higher order molecular necklaces yet this approach of “threading-followed-by-ring-closing-metathesis” for the first time produces kinetically and thermodynamically stable, well-defined, homogeneous molecular necklace which was well characterized by one-dimensional, two-dimensional, variable temperature proton NMR spectroscopy and ESI mass spectroscopy.
Starting Page	3504
Ending Page	3515
Page Count	12
File Format	HTM / HTML PDF
ISSN	14770520
Volume Number	9
Issue Number	9
Journal	Organic & Biomolecular Chemistry
DOI	10.1039/c0ob01034k
Language	English
Publisher	Royal Society of Chemistry
Access Restriction	Open
Subject Keyword	Spectroscopy Robert H. Grubbs Ion Nuclear magnetic resonance spectroscopy Proton nuclear magnetic resonance Dynamic covalent chemistry Grubbs Macrocycle Salt metathesis reaction Hexafluorophosphate Alkene ESI Molecular self-assembly Olefin metathesis Lipophilicity Rotaxane Hydrogen bond
Content Type	Text
Resource Type	Article
Subject	Biochemistry Organic Chemistry Physical and Theoretical Chemistry

Sl.	Authority	Responsibilities	Communication Details
1	Ministry of Education (GoI), Department of Higher Education	Sanctioning Authority	https://www.education.gov.in/ict-initiatives
2	Indian Institute of Technology Kharagpur	Host Institute of the Project: The host institute of the project is responsible for providing infrastructure support and hosting the project	https://www.iitkgp.ac.in
3	National Digital Library of India Office, Indian Institute of Technology Kharagpur	The administrative and infrastructural headquarters of the project	Dr. B. Sutradhar bsutra@ndl.gov.in
4	Project PI / Joint PI	Principal Investigator and Joint Principal Investigators of the project	Dr. B. Sutradhar bsutra@ndl.gov.in Prof. Saswat Chakrabarti will be added soon
5	Website/Portal (Helpdesk)	Queries regarding NDLI and its services	support@ndl.gov.in
6	Contents and Copyright Issues	Queries related to content curation and copyright issues	content@ndl.gov.in
7	National Digital Libarray of India Club (NDLI Club)	Queries related to NDLI Club formation, support, user awareness program, seminar/symposium, collaboration, social media, promotion, and outreach	clubsupport@ndl.gov.in
8	Digital Preservation Centre (DPC)	Assistance with digitizing and archiving copyright-free printed books	dpc@ndl.gov.in
9	IDR Setup or Support	Queries related to establishment and support of Institutional Digital Repository (IDR) and IDR workshops	idr@ndl.gov.in

Application of a metathesis reaction in the synthesis of sterically congested medium-sized rings. A direct ring closing versus a double bond migration–ring closing process

Formation of [2]rotaxanes by encircling [20], [21] and [22]crown ethers onto the dibenzylammonium dumbbell

A catalytically driven organometallic molecular motor

Superior anion induced shuttling behaviour exhibited by a halogen bonding two station rotaxane

Stereoselective synthesis of macrocyclic peptides via a dual olefin metathesis and ethenolysis approach

Low-temperature crosslinking of anion exchange membranes

Bimodal supramolecular functionalization of carbon nanotubes triggered by covalent bond formation

Grubbs Catalyst 2nd Generation: Synthesis and Activity of Ruthenium-Based Olefin Metathesis Catalysts

Liquid/solid phase transfer activation of Grubbs-type alkene metathesis catalysts; application of silver salts of sulfonated polystyrene

Template-directed synthesis of kinetically and thermodynamically stable molecular necklace using ring closing metathesis

Similar Documents

Application of a metathesis reaction in the synthesis of sterically congested medium-sized rings. A direct ring closing versus a double bond migration–ring closing process

Formation of [2]rotaxanes by encircling [20], [21] and [22]crown ethers onto the dibenzylammonium dumbbell

A catalytically driven organometallic molecular motor

Superior anion induced shuttling behaviour exhibited by a halogen bonding two station rotaxane

Stereoselective synthesis of macrocyclic peptides via a dual olefin metathesis and ethenolysis approach

Low-temperature crosslinking of anion exchange membranes

Bimodal supramolecular functionalization of carbon nanotubes triggered by covalent bond formation

Grubbs Catalyst 2nd Generation: Synthesis and Activity of Ruthenium-Based Olefin Metathesis Catalysts

Liquid/solid phase transfer activation of Grubbs-type alkene metathesis catalysts; application of silver salts of sulfonated polystyrene

Template-directed synthesis of kinetically and thermodynamically stable molecular necklace using ring closing metathesis