scholarly journals Synthesis and Configurational Assignment of Vinyl Sulfoximines and Sulfonimidamides

2021 ◽  
Author(s):  
Gregory Craven ◽  
Edward L. Briggs ◽  
Charlotte Zammit ◽  
Alex McDermott ◽  
Stephanie Greed ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Late Stage ◽  
Chemical Biology ◽  
Chemical Space ◽  
Protein Inhibitors ◽  
Electronic Circular Dichroism ◽  
Configurational Assignment ◽  
The Absolute ◽  
Synthetic Methodologies ◽  
Circular Dichroïsm

Vinyl sulfones and sulfonamides are valued for their use as electrophilic warheads in covalent protein inhibitors. Conversely, the S(VI) aza-isosteres thereof, vinyl sulfoximines and sulfonimidamides, are far less studied and have yet to be applied to the field of protein bioconjugation. Herein, we report a range of different synthetic methodologies for constructing vinyl sulfoximine and vinyl sulfonimidamide architectures that allows access to new areas of electrophilic chemical space. We demonstrate how late stage functionalization can be applied to these motifs to incorporate alkyne tags, generating fully functionalized probes for future chemical biology applications. Finally, we establish a workflow for determining the absolute configuration of enantioenriched vinyl sulfoximines and sulfonimidamides by comparing experimentally and computationally determined electronic circular dichroism spectra, enabling access to configurationally assigned enantiomeric pairs by separation.

scholarly journals Synthesis and Configurational Assignment of Vinyl Sulfoximines and Sulfonimidamides

2021 ◽  
Author(s):  
Gregory Craven ◽  
Edward L. Briggs ◽  
Charlotte Zammit ◽  
Alex McDermott ◽  
Stephanie Greed ◽  
...  
Keyword(s):  
Absolute Configuration ◽  
Late Stage ◽  
Chemical Biology ◽  
Chemical Space ◽  
Protein Inhibitors ◽  
Electronic Circular Dichroism ◽  
Configurational Assignment ◽  
The Absolute ◽  
Synthetic Methodologies ◽  
Circular Dichroïsm

Vinyl sulfones and sulfonamides are valued for their use as electrophilic warheads in covalent protein inhibitors. Conversely, the S(VI) aza-isosteres thereof, vinyl sulfoximines and sulfonimidamides, are far less studied and have yet to be applied to the field of protein bioconjugation. Herein, we report a range of different synthetic methodologies for constructing vinyl sulfoximine and vinyl sulfonimidamide architectures that allows access to new areas of electrophilic chemical space. We demonstrate how late stage functionalization can be applied to these motifs to incorporate alkyne tags, generating fully functionalized probes for future chemical biology applications. Finally, we establish a workflow for determining the absolute configuration of enantioenriched vinyl sulfoximines and sulfonimidamides by comparing experimentally and computationally determined electronic circular dichroism spectra, enabling access to configurationally assigned enantiomeric pairs by separation.

scholarly journals Absolute Configuration Sensing of Chiral Aryl- and Aryloxy-Propionic Acids by Biphenyl Chiroptical Probes

Chemosensors ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 154
Author(s):  
Stefania Vergura ◽  
Stefano Orlando ◽  
Patrizia Scafato ◽  
Sandra Belviso ◽  
Stefano Superchi
Keyword(s):  
Circular Dichroism ◽  
Absolute Configuration ◽  
Optical Rotation ◽  
Environmental Pollutants ◽  
Red Shift ◽  
Electronic Circular Dichroism ◽  
Configuration Assignment ◽  
Clear Sign ◽  
The Absolute ◽  
Circular Dichroïsm

The absolute configuration of chiral 2-aryl and 2-aryloxy propionic acids, which are among the most common chiral environmental pollutants, has been readily and reliably established by either electronic circular dichroism spectroscopy or optical rotation measurements employing suitably designed 4,4′-disubstituted biphenyl probes. In fact, the 4,4′-biphenyl substitution gives rise to a red shift of the diagnostic electronic circular dichroism signal of the biphenyl A band employed for the configuration assignment, removing its overlap with other interfering dichroic bands and allowing its clear sign identification. The largest A band red shift, and thus the most reliable results, are obtained by employing as a probe the 4,4′-dinitro substituted biphenylazepine 3c. The method was applied to the absolute configuration assignment of 2-arylpropionic acids ibuprofen (1a), naproxen (1b), ketoprofen (1c) and flurbiprofen (1d), as well as to the 2-aryloxypropionic acids 2-phenoxypropionic acid (2a) and 2-naphthoxypropionic acid (2b). This approach, allowing us to reveal the sample’s absolute configuration by simple optical rotation measurements, is potentially applicable to online analyses of both the enantiomeric composition and absolute configuration of these chiral pollutants.

scholarly journals Use of Circular Dichroism to Determine the Absolute Configuration of a Pimarane Diterpenoid from the Southern African Sclerocroton integerrimus (Euphorbiaceae)

2014 ◽  
Vol 9 (8) ◽  
pp. 1934578X1400900 ◽  
Author(s):  
Vuyelwa J. Tembu ◽  
Moses K. Langat ◽  
Neil R. Crouch ◽  
Dulcie A. Mulholland
Keyword(s):  
Circular Dichroism ◽  
Absolute Configuration ◽  
Spectroscopic Analysis ◽  
Stem Bark ◽  
Electronic Circular Dichroism ◽  
The Absolute ◽  
Circular Dichroïsm

From the stem bark and leaves of Sclerocroton integerrimus, eight compounds, including 17-hydroxy- ent-pimara-8(14),15-dien-3-one (1), were isolated. The structures of the compounds were determined on the basis of spectroscopic analysis. The absolute configuration of 17-hydroxy- ent-pimara-8(14),15-dien-3-one was confirmed from electronic circular dichroism studies.

Stereodynamic Analysis of New Atropisomeric 4,7-Di(naphthalen-1-yl)-5,6-dinitro-1H-indoles

Synlett ◽  
2018 ◽  
Vol 29 (16) ◽  
pp. 2161-2166 ◽  
Author(s):  
Giovanni Petrillo ◽  
Michele Mancinelli ◽  
Angela Pagano ◽  
Emanuela Marotta ◽  
Andrea Mazzanti ◽  
...  
Keyword(s):  
Kinetic Analysis ◽  
Absolute Configuration ◽  
Indole Ring ◽  
Electronic Circular Dichroism ◽  
X Ray ◽  
Dft Simulation ◽  
Rotational Barriers ◽  
Td Dft ◽  
The Absolute ◽  
Circular Dichroïsm

A series of atropisomeric molecules containing the indole ring and two stereogenic axes were prepared. The four atropisomers were resolved by enantioselective HPLC. The rotational barriers of the indole–naphthyl axes were evaluated by means of kinetic analysis either by NMR or enantioselective HPLC. The absolute configuration of the ­atropisomers was determined by a combination of X-ray spectroscopy and TD-DFT simulation of electronic circular dichroism spectra.

scholarly journals α-Photooxygenation of chiral aldehydes with singlet oxygen

2019 ◽  
Vol 15 ◽  
pp. 2076-2084 ◽  
Author(s):  
Dominika J Walaszek ◽  
Magdalena Jawiczuk ◽  
Jakub Durka ◽  
Olga Drapała ◽  
Dorota Gryko
Keyword(s):  
Circular Dichroism ◽  
Singlet Oxygen ◽  
Absolute Configuration ◽  
Dft Methods ◽  
Catalyst Structure ◽  
Electronic Circular Dichroism ◽  
Silyl Ethers ◽  
Td Dft ◽  
The Absolute ◽  
Circular Dichroïsm

Organocatalytic α-oxygenation of chiral aldehydes with photochemically generated singlet oxygen allows synthesizing chiral 3-substituted 1,2-diols. Stereochemical results indicate that the reaction in the presence of diarylprolinol silyl ethers is highly diastereoselective and that the configuration of a newly created stereocenter at the α-position depends predominantly on the catalyst structure. The absolute configuration of chiral 1,2-diols has been unambiguously established based on electronic circular dichroism (ECD) and TD-DFT methods.

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