Pentacoordinate silicon derivatives with a chloromethyl ligand are versatile compounds that are usually obtained from the corresponding tetravalent trialkoxy- or trihalogeno(chloromethyl)silane. We describe herein the synthesis of a chloromethylsilicate bearing two Martin's ligands readily obtained by addition of in situ generated chloromethyllithium to a spirosilane. The reactivity of this new species was evaluated and it has been established that the chloride is displaced by strong nucleophiles such as alkyllithiums and (hetero)aryllithiums. In Lewis acidic conditions, the pentacoordinate silicon species rearranges through a formal insertion of a methylene into one Si-C bond, to form a new tetravalent spirosilane with a six-membered ring. The same kind of rearrangement can be triggered also by addition of a Lewis base. The mechanism of the rearrangement in both conditions has been studied by means of DFT calculations.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8956079 | PMC |
| http://dx.doi.org/10.3390/molecules27061767 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Lewis Base-Catalyzed Dynamic Kinetic Asymmetric Transformation of Racemic Chlorosilanes Route to -Stereogenic Silylethers.
J Am Chem Soc
August 2024
Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, Sichuan Engineering Laboratory for Plant-Sourced Drug and Sichuan Research Center for Drug Precision Industrial Technology, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
Enantiopure -stereogenic organosilanes are highly valued in the fields of organic synthesis, development of advanced materials, and drug discovery. However, they are not naturally occurring, and their synthesis has been largely confined to resolution of racemic silanes or desymmetrization of symmetric silanes. In contrast, the dynamic kinetic asymmetric transformation (DYKAT) of racemic organosilanes offers a mechanistically distinct approach and would broaden the accessibility of -stereogenic silanes in an enantioconvergent manner.
View Article and Find Full Text PDFStereoselective Entry into α,α'-C-Oxepane Scaffolds through a Chalcogen Bonding Catalyzed Strain-Release C-Septanosylation Strategy.
Angew Chem Int Ed Engl
July 2024
Abteilung Chemische Biologie, Max Planck Institut für Molekulare Physiologie, Otto-Hahn-Straße 11, 44227, Dortmund, Germany.
The utility of unconventional noncovalent interactions (NCIs) such as chalcogen bonding has lately emerged as a robust platform to access synthetically difficult glycosides stereoselectively. Herein, we disclose the versatility of a phosphonochalcogenide (PCH) catalyst to facilitate access into the challenging, but biologically interesting 7-membered ring α,α'-C-disubstituted oxepane core through an α-selective strain-release C-glycosylation. Methodically, this strategy represents a switch from more common but entropically less desired macrocyclizations to a thermodynamically favored ring-expansion approach.
View Article and Find Full Text PDF{-[1-(2-Oxidophen-yl)ethyl-idene]-dl-alaninato}(pentane-1,5-di-yl)silicon(IV).
IUCrdata
March 2024
Institut für Anorganische Chemie, Technische Universität Bergakademie Freiberg, Leipziger Str. 29, 09599 Freiberg, Germany.
The title Si complex, CHNOSi, is built up by a tridentate dinegative Schiff base ligand bound to a sila-cyclo-hexane unit. The coordination geometry of the penta-coordinated Si atom is a distorted trigonal bipyramid. The presence of the sila-cyclo-hexane ring in the complex leads to an unusual coordination geometry of the Si atom with the N atom from the Schiff base ligand and an alkyl-C atom in apical positions of the trigonal bipyramid.
View Article and Find Full Text PDFStereomutations in silicate oligomerization: the role of steric hindrance and intramolecular hydrogen bonding.
Phys Chem Chem Phys
February 2024
Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, India.
Stereomutation has previously been explored in the literature with regard to the different mechanisms and activation energy barriers between different forms. However, the forces which govern stereomutations within the intermediate steps in chemical reactions have not been explored previously, a topic addressed in this article. The process of silicate oligomerization has been chosen in this study and it is demonstrated that steric hindrance of molecules and intramolecular hydrogen bonding govern the stereomutation of intermediate pentacoordinate silicon compounds in the silicate oligomerization process.
View Article and Find Full Text PDFLewis Acid-Base Adducts of α-Amino Acid-Derived Silaheterocycles and -Methylimidazole.
Molecules
November 2023
Institut für Anorganische Chemie, TU Bergakademie Freiberg, D-09596 Freiberg, Germany.
In chloroform solution, the reaction of bis(tert-butylamino)dimethylsilane ((BuNH)SiMe) and an α-amino acid (α-amino isobutyric acid, ; D-phenylglycine, ; L-valine, ) in the presence of -methylimidazole (NMI) gave rise to the formation of the pentacoordinate silicon complexes , and , respectively. Therein, the amino acid building block was a di-anionic bidentate chelator at the silicon atom. In solution, the complexes were involved in rapid coordination-dissociation equilibria between the pentacoordinate Si complex (e.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!