Kinetic Resolution of Acyclic Secondary Allylic Silyl Ethers Catalyzed by Chiral Ketones

2001 ◽  
Vol 66 (13) ◽  
pp. 4619-4624 ◽  
Author(s):  
Dan Yang ◽  
Guan-Sheng Jiao ◽  
Yiu-Chung Yip ◽  
Tsz-Hin Lai ◽  
Man-Kin Wong
Keyword(s):  
Kinetic Resolution ◽  
Silyl Ethers ◽  
Chiral Ketones

ChemInform Abstract: Kinetic Resolution of Acyclic Secondary Allylic Silyl Ethers Catalyzed by Chiral Ketones.

ChemInform ◽  
2010 ◽  
Vol 32 (46) ◽  
pp. no-no
Author(s):  
Dan Yang ◽  
Guan-Sheng Jiao ◽  
Yiu-Chung Yip ◽  
Tsz-Hin Lai ◽  
Man-Kin Wong
Keyword(s):  
Kinetic Resolution ◽  
Silyl Ethers ◽  
Chiral Ketones

Synthesis of B-ring-fluorinated (−)-epicatechin gallate derivatives

2020 ◽  
Vol 18 (21) ◽  
pp. 4024-4028
Author(s):  
David D. S. Thieltges ◽  
Kai D. Baumgarten ◽  
Carina S. Michaelis ◽  
Constantin Czekelius
Keyword(s):  
Kinetic Resolution ◽  
Convergent Sequence ◽  
Epicatechin Gallate

Electronically modified, fluorinated catechins and epicatechins are enantioselectively synthesized in a short, convergent sequence via kinetic resolution.

Probing the Parallel Kinetic Resolution of Racemic Oxazolidinones using Quasi-enantiomeric Profens

2006 ◽  
Author(s):  
Jason Eames ◽  
Gregory Coumbarides ◽  
Marco Dingjan ◽  
Tony Flinn ◽  
Northern Northen ◽  
...  
Keyword(s):  
Kinetic Resolution ◽  
Parallel Kinetic Resolution

SuFExable Polymers with Helical Structures Derived from Thionyl Tetrafluoride (SOF4)

2019 ◽  
Author(s):  
Suhua Li ◽  
Gencheng Li ◽  
Bing Gao ◽  
Sidharam P. Pujari ◽  
Xiaoyan Chen ◽  
...  
Keyword(s):  
Functional Polymers ◽  
Polymer Chains ◽  
New Materials ◽  
Helical Structures ◽  
Polymer Backbone ◽  
Silyl Ethers ◽  
Helical Polymer ◽  
Key Characteristics ◽  
Post Modification ◽  
Individual Polymer

The first SuFEx click chemistry synthesis of SOF<sub>4</sub>-derived copolymers based upon the polymerization of bis(iminosulfur oxydifluorides) and bis(aryl silyl ethers) is described. This novel class of SuFEx polymer presents two key characteristics: First, the newly created [-N=S(=O)F-O-] polymer backbone linkages are themselves SuFExable and primed to undergo further high-yielding and precise SuFEx-based post-modification with phenols or amines to yield branched functional polymers. Second, studies of individual polymer chains of several of these new materials indicate the presence of helical polymer structures, which itself suggests a preferential approach of new monomers onto the growing polymer chain upon the formation of the stereogenic linking moiety.

Catalyst- and Silane- Controlled Enantioselective Hydrofunctionalization of Alkenes by Cobalt-Catalyzed Hydrogen Atom Transfer and Radical-Polar Crossover

2020 ◽  
Author(s):  
Kousuke Ebisawa ◽  
Kana Izumi ◽  
Yuka Ooka ◽  
Hiroaki Kato ◽  
Sayori Kanazawa ◽  
...  
Keyword(s):  
Hydrogen Atom ◽  
Absolute Configuration ◽  
Kinetic Resolution ◽  
Hydrogen Atom Transfer ◽  
Biologically Active ◽  
Atom Transfer ◽  
High Concentration ◽  
Chain Reaction ◽  
Radical Chain ◽  
Radical Chain Reaction

Catalytic enantioselective synthesis of tetrahydrofurans, which are found in the structures of many biologically active natural products, via a transition-metal catalyzed-hydrogen atom transfer (TM-HAT) and radical-polar crossover (RPC) mechanism is described herein. Hydroalkoxylation of non-conjugated alkenes proceeded efficiently with excellent enantioselectivity (up to 94% ee) using a suitable chiral cobalt catalyst, <i>N</i>-fluoro-2,4,6-collidinium tetrafluoroborate, and diethylsilane. Surprisingly, absolute configuration of the product was highly dependent on the steric hindrance of the silane. Slow addition of the silane, the dioxygen effect in the solvent, thermal dependency, and DFT calculation results supported the unprecedented scenario of two competing selective mechanisms. For the less-hindered diethylsilane, a high concentration of diffused carbon-centered radicals invoked diastereoenrichment of an alkylcobalt(III) intermediate by a radical chain reaction, which eventually determined the absolute configuration of the product. On the other hand, a more hindered silane resulted in less opportunity for radical chain reaction, instead facilitating enantioselective kinetic resolution during the late-stage nucleophilic displacement of the alkylcobalt(IV) intermediate.

A Facile, Efficient and Chemoseletive Deprotection of Silyl Ethers Using Zinc (II) Trifluoromethanesulfonate

2018 ◽  
Vol 15 (3) ◽  
Author(s):  
Kotthireddy Thirumal Reddy ◽  
Reddymasu Sreenivasulu ◽  
Deekala Veronica ◽  
Choragudi Chandrasekhar ◽  
Kowthalam Anitha ◽  
...  
Keyword(s):  
Silyl Ethers
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