Vibrational Circular Dichroism and Absolute Configuration of Chiral Sulfoxides:tert-Butyl Methyl Sulfoxide

Aamouche, A.; Devlin, F. J.; Stephens, Philip J.; Drabowicz, J.; Bujnicki, Bogdan; Mikołajczyk, M.

doi:10.1002/1521-3765(20001215)6:24<4479::aid-chem4479>3.0.co;2-2

Cited by 40 publications

(23 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, only a few theoretical studies have been carried out on vibrational circular dichroism (VCD) and infrared spectroscopy (IR) as a function of temperature in beryllium–boron clusters [ 33 , 60 ]. We emphasize that there are neither theoretical nor experimental studies of VCD/IR spectra in chiral Be 4 B 8 clusters, although VCD/IR spectra give insight into the geometrical structure [ 61 , 62 , 63 , 64 ]. Recently, Castiglioni et al reviewed experimental aspects of solid-state circular dichroism [ 65 ], and Avilés-Moreno et al reported the experimental and theoretical IR/VCD spectra of various compounds [ 66 , 67 , 68 , 69 ].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Theoretical Prediction of Structures, Vibrational Circular Dichroism, and Infrared Spectra of Chiral Be4B8 Cluster at Different Temperatures

et al. 2021

View full text Add to dashboard Cite

Lowest-energy structures, the distribution of isomers, and their molecular properties depend significantly on geometry and temperature. Total energy computations using DFT methodology are typically carried out at a temperature of zero K; thereby, entropic contributions to the total energy are neglected, even though functional materials work at finite temperatures. In the present study, the probability of the occurrence of one particular Be4B8 isomer at temperature T is estimated by employing Gibbs free energy computed within the framework of quantum statistical mechanics and nanothermodynamics. To identify a list of all possible low-energy chiral and achiral structures, an exhaustive and efficient exploration of the potential/free energy surfaces is carried out using a multi-level multistep global genetic algorithm search coupled with DFT. In addition, we discuss the energetic ordering of structures computed at the DFT level against single-point energy calculations at the CCSD(T) level of theory. The total VCD/IR spectra as a function of temperature are computed using each isomer’s probability of occurrence in a Boltzmann-weighted superposition of each isomer’s spectrum. Additionally, we present chemical bonding analysis using the adaptive natural density partitioning method in the chiral putative global minimum. The transition state structures and the enantiomer–enantiomer and enantiomer–achiral activation energies as a function of temperature evidence that a change from an endergonic to an exergonic type of reaction occurs at a temperature of 739 K.

show abstract

Section: Introductionmentioning

confidence: 99%

“…It usually is four times in magnitude smaller than IR absorption [ 66 ] and yields information on the lowest energy conformation in solution [ 71 , 72 ]; thus, the chiral molecule’s absolute configuration can be determined employing the VCD spectra. [ 63 , 73 , 74 , 75 ].…”

Section: Introductionmentioning

confidence: 99%

Theoretical Prediction of Structures, Vibrational Circular Dichroism, and Infrared Spectra of Chiral Be4B8 Cluster at Different Temperatures

et al. 2021

View full text Add to dashboard Cite

show abstract

“…The condensation of MeMgBr with sulfinate ester 2 R S in toluene at 0 °C took place with complete inversion of configuration at sulfur, and led smoothly to ( S S )‐methyl tert ‐butyl sulfoxide ( 11 S S ) in excellent yield and in enantiopure form (Scheme ). The absolute configuration of the sulfoxide product was determined by specific rotation, as proposed by us and others,27 and was confirmed by circular dichroism 34,35. The specific rotation of 11 S S was determined using EtOH as solvent instead of chloroform, which was initially proposed, but which usually leads to inconsistent results.…”

Section: Resultsmentioning

confidence: 93%

“…Methyl tert ‐Butyl ( S )‐Sulfoxide (11 S S ): 25,34,44 A solution of 2 R S (10 g, 31.04 mmol) in toluene (100 mL) was treated with a 1 M methylmagnesium bromide solution in diethyl ether (43.46 mL, 43.46 mmol). The mixture was stirred for 1 h, then saturated aqueous NH 4 Cl was added.…”

Section: Methodsmentioning

confidence: 99%

DMAP‐Catalysed Sulfinylation of Diacetone‐D‐Glucose: Improved Method for the Synthesis of Enantiopure tert‐Butyl Sulfoxides and tert‐Butanesulfinamides

Chelouan¹,

Recio²,

Alcudia³

et al. 2014

Eur J Org Chem

View full text Add to dashboard Cite

An improved method for the tert‐butanesulfinylation of diacetone glucose with tert‐butanesulfinyl chloride is reported. The method is based on a beneficial effect of catalytic DMAP, which enhances both the rate of the reaction and the enantioselectivity of the process to give (RS)‐diastereomer 2RS with a 94 % de and in quantitative yield. (RS)‐DAG sulfinate ester 2RS is an excellent intermediate for the synthesis of enantiopure tert‐butyl sulfoxides. Grignard agents and organolithium reagents can displace smoothly the diacetone glucose moiety to give synthetically relevant enantiopure sulfoxides, including highly functionalized derivatives, in high yields and with high enantioselectivities. (RS)‐DAG sulfinate ester 2RS is also an excellent N‐sulfinylating agent; simple addition of LiHMDS (lithium hexamethyldisilazide) in THF gives (SS)‐tert‐butanesulfinamide, and N‐tert‐butanesulfinylimines are then formed in a two‐step one‐pot manner. N‐Alkylated tert‐butanesulfinamides are formed by the condensation of 2RS with lithium amides.

show abstract

“…How does one establish the correlation between the absolute configuration of varied amines and 19 F NMR signal of their corresponding alpha-fluorinated phenyl acetic amides excluding arbitrary assignment? Considering that the assignment of absolute configuration of chiral molecules using a circular dichroism spectrometer by comparing the experimental and calculated CD spectra has been well-established (Dickins et al, 1999; Aamouche et al, 2000; Huang et al, 2000; Pescitelli and Bruhn, 2016), we wonder if we can do the same thing with NMR.…”

Section: Introductionmentioning

confidence: 99%

Assigning the Absolute Configurations of Chiral Primary Amines Based on Experimental and DFT-Calculated 19F Nuclear Magnetic Resonance

Yang

Bian

et al. 2019

Front. Chem.

View full text Add to dashboard Cite

In this work, a novel method for assigning the absolute configuration of a chiral primary amine has been developed based on the experimental and DFT-calculated 19 F NMR chemical shift differences of its derived two fluorinated amides by reacting with two enantiomers of a chiral derivatizing agent FPP (α-fluorinated phenylacetic phenylselenoester) separately. Comparing the experimental chemical shift difference of (R)-FPA-amide/(S)-FPA-amide with the calculated Δδ α-F R,S of (R)-FPA-(R)-amide/(S)-FPA-(R)-amide, if the experimental Δδ α-F R,S has the same symbol (positive or negative) as one of the theoretical Δδ α-F R,S , the assigned configuration of the amine is considered to be consistent with the theoretical one. Our method could be applied to a broad substrate scope avoiding wrong conclusion due to empirical judgment.

show abstract

Vibrational Circular Dichroism and Absolute Configuration of Chiral Sulfoxides:tert-Butyl Methyl Sulfoxide

Cited by 40 publications

References 42 publications

Theoretical Prediction of Structures, Vibrational Circular Dichroism, and Infrared Spectra of Chiral Be4B8 Cluster at Different Temperatures

Theoretical Prediction of Structures, Vibrational Circular Dichroism, and Infrared Spectra of Chiral Be4B8 Cluster at Different Temperatures

DMAP‐Catalysed Sulfinylation of Diacetone‐D‐Glucose: Improved Method for the Synthesis of Enantiopure tert‐Butyl Sulfoxides and tert‐Butanesulfinamides

Assigning the Absolute Configurations of Chiral Primary Amines Based on Experimental and DFT-Calculated 19F Nuclear Magnetic Resonance

Contact Info

Product

Resources

About