Optically active amines. 25. Circular dichroism of 1-substituted indans

Smith, Howard E.; Padilla, Benjamin G.; Neergaard, Jon R.; Chen, Fuming

doi:10.1021/ja00487a010

Cited by 16 publications

(6 citation statements)

References 17 publications

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“…Since B3LYP calculations systematically overestimate electronic transition energies resulting in a blue shift of the calculated spectra, the predicted ECD spectra were corrected by parallel shift toward longer wavelengths by a value corresponding to the difference between experimental and calculated (from the same molecular geometry) UV absorption maxima (see Supporting Information). Both basis sets yielded for 10 a negative Cotton effect around 275 nm, in agreement with experimental results. , For the model compounds 9a and 9b , for which no experimental data have been reported, two practically isoenergetic conformations were identified, with the hydroxy group periplanar to the aromatic ring and the hydroxy group proton either anti or syn to the methylene group. However, the hydroxy group conformation had no influence on the sign of the calculated Cotton effects associated with the long-wavelength transitions, which was negative for the R -enantiomer 9a (as for 10 ) and positive for the S -enantiomer 9b (see Supporting Information).…”

Section: Resultssupporting

confidence: 83%

Production of Unusual Dispiro Metabolites inPestalotiopsis virgatulaEndophyte Cultures: HPLC-SPE-NMR, Electronic Circular Dichroism, and Time-Dependent Density-Functional Computation Study

et al. 2011

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The endophytic fungus Pestalotiopsis virgatula, derived from the plant Terminalia chebula and previously found to produce a large excess of a single metabolite when grown in the minimal M1D medium, was induced to produce a variety of unusual metabolites by growing in potato dextrose broth medium. Analysis of the fermentation medium extract was performed using an HPLC-PDA-MS-SPE-NMR hyphenated system, which led to the identification of a total of eight metabolites (1-8), six of which are new. Most of the metabolites are structurally related and are derivatives of benzo[c]oxepin, rare among natural products. This includes dispiro derivatives 7 and 8 (pestalospiranes A and B), having a novel 1,9,11,18-tetraoxadispiro[6.2.6.2]octadecane skeleton. Relative and absolute configurations of the latter were determined by a combination of NOESY spectroscopy and electronic circular dichroism spectroscopy supported by time-dependent density-functional theory calculations (B3LYP/TZVP level). This work demonstrates that a largely complete structure elucidation of numerous metabolites present in a raw fermentation medium extract can be performed by the HPLC-SPE-NMR technique using only a small amount of the extract, even with unstable metabolites that are difficult to isolate by traditional methods.

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Section: Resultssupporting

confidence: 83%

Production of Unusual Dispiro Metabolites inPestalotiopsis virgatulaEndophyte Cultures: HPLC-SPE-NMR, Electronic Circular Dichroism, and Time-Dependent Density-Functional Computation Study

et al. 2011

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“…The circular dichroism spectra of a substantial number of chiral perhydrobenzocycloalkenes with planar rings have been reported, ,,, and the benzene sector and the benzene chirality rules were used to correlate the sign of their 1 L b CEs with their absolute configurations . The CD data for ( S )-1-amino-1,2-dihydrobenzocyclobutene [( S )- 54 ] and some chiral 1-substituted indans [( S )- 55 a − f and ( R )- 55g − i ] are shown in Table .…”

Section: F Perhydrobenzocycloalkenes1 Planar Ring Systemsmentioning

confidence: 99%

Chiroptical Properties of the Benzene Chromophore. A Method for the Determination of the Absolute Configurations of Benzene Compounds by Application of the Benzene Sector and Benzene Chirality Rules

Smith

1998

Chem. Rev.

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e {45} 266 [-3.6] e,h {37} 268 [-22] e,i {42} 268 [-23] j,k {55} c N(CH3)3I EA: 269 (280) i 269 (280) CD: 269 [-21] e,i {56} 269 (-24) e {29} d OH EA: 267 (90) 267 (130) i 267 (79) 268 (75) l CD: 268 [-17] {57} 268 [-39] i {58} 269 [-6.7] e {59} 268 [-2.4] e,l {59} 262 [-8.2] e,i,m {60} e OCH3 EA: 267 CD: 268 [-7.5] e,i {61} 267 [-6.1] e {62} 261 [-17] e,j,m {60} 262 [-7.6] e,i,m {60} f CH3 EA: 268 (110) n 267 (79) 268 (120) l CD: 267 [-160] e,o {63} 268 [+2.9] {64} 269 [-12] l {64} 261 [+9.1] i,m {60} g C(CH3)3 EA: CD: 260 [+8.1] i,m {60} 262 [-6.5] j,m {60} 261 [+13] i,m {60} h CF3 EA: CD: 261 [-7.3] i,m {60} 261 [-7.6] j,m {60} 260 [-7.1] i,m {60} i Cl EA: 272 (110) CD: 273 [-3.3] e {29} j F EA: 268 (88) 267 (120) l CD: 268 [-18] e {64} 268 [-12] e,l {64} k SH EA: 271 (100) f CD: 270 [+27] e {29}a Methanol as the solvent or as otherwise noted. b Molar absorptivity. c Molar dichroic absorption. ∆ ) [θ]/3300 where [θ] is the molecular ellipticity. d Original report of the complete electronic absorption (EA) and circular dichroism (CD) data. e Enantiomer used. f Shoulder. g Isooctane as the solvent. h 1,1,1,3,3,3-Hexafluoro-2-propanol as the solvent. i Ethanol as the solvent. j Water as the solvent. k Sodium and chloride ions not present. l Potassium cation. m Center maximum of three 1 Lb CEs. n n-Heptane as the solvent. o Methylcyclohexane-isopentane 1:3 as the solvent.

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“…Substituted indans have attracted interest for their chiroptical properties since early 1970s, mainly in terms of ECD associated with n−σ*, σ–π*, π–-σ*, and π–π* transitions. , More recently, various jet-cooled spectroscopies were undertaken for substituted indans, where low-frequency ring puckering modes were investigated. − In the early stages of VCD research, emphasis was placed on spectra–structure correlations and qualitative interpretations. In this connection, the methine-hydrogen bending mode has been suggested to generate a VCD band with its sign correlating with the absolute configuration (AC) in a series of related compounds.…”

Section: Introductionmentioning

confidence: 99%

Chiral Molecular Structures of Substituted Indans: Ring Puckering, Rotatable Substituents, and Vibrational Circular Dichroism

Johnson

Polavarapu

2019

ACS Omega

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The chiral molecular structures of four different substituted indans, namely, ( S )-1-methylindan, ( R )-1-methylindan-1-d, ( R )-1-aminoindan, and ( S )-1-indanol, were investigated using experimental vibrational absorption and vibrational circular dichroism spectra and corresponding spectra predicted using quantum chemical (QC) calculations. All of these molecules possess two ring puckering conformations, with ring puckering leading to the pseudoequatorial substituent being approximately four times more abundant over that leading to the pseudoaxial substituent. The amino group in 1-aminoindan has three conformations arising from the rotation of NH 2 group, for each ring puckering conformation, resulting in a total of six conformations. Whereas 1-indanol in the nonhydrogen-bonding solvent CCl 4 also has six conformations similar to those of 1-aminoindan, 1-indanol in the hydrogen-bonding solvent DMSO- d 6 adopts numerous conformations, of which 30 conformers are considered to have at least ∼1% or more population. In DMSO solution, ring puckering leading to pseudoequatorial substituent accounts for 77% population and 23% for pseudoaxial substituent. The QC spectra predicted for the geometry optimized conformers are found to be in excellent quantitative agreement with corresponding experimental spectra in all of the molecules considered. The procedures suggested in this work are hoped to provide successful pathways for future chiral molecular structural analyses.

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Optically active amines. 25. Circular dichroism of 1-substituted indans

Cited by 16 publications

References 17 publications

Production of Unusual Dispiro Metabolites inPestalotiopsis virgatulaEndophyte Cultures: HPLC-SPE-NMR, Electronic Circular Dichroism, and Time-Dependent Density-Functional Computation Study

Production of Unusual Dispiro Metabolites inPestalotiopsis virgatulaEndophyte Cultures: HPLC-SPE-NMR, Electronic Circular Dichroism, and Time-Dependent Density-Functional Computation Study

Chiroptical Properties of the Benzene Chromophore. A Method for the Determination of the Absolute Configurations of Benzene Compounds by Application of the Benzene Sector and Benzene Chirality Rules

Chiral Molecular Structures of Substituted Indans: Ring Puckering, Rotatable Substituents, and Vibrational Circular Dichroism

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