Fillmore Freeman

University of California, Irvine | UCI ·  Department of Chemistry

The conformations, equilibrium structures, hydrogen bonds, and noncovalent interactions involved in the mechanisms of tautomerization, condensations, and C-sulfenylation and O-sulfenylation of 2,4-pentanedione by sulfur hydride hydroxide (hydrogen thioperoxide, oxadisulfane, H-SOH) have been studied using BD(T), CCSD(T), and QCISD(T) with the cc-pV...

The density functionals B3LYP, B3PW91, M062X, and CAM-B3LYP with the 6-311+G(d,p) basis set predict the cysteine sulfenic acid O-sulfenylation of the s-cis-ketoenol tautomer of 1,3-cyclohexanedione proceeds through a cyclic 14-membered transition state structure containing three water molecules.

Equilibrium and molecular structures, relative energies of conformers of gaseous cysteine (Cys, C, Cys-SH) and gaseous cysteine sulfenic acid (Cys-SOH), and the mechanisms of the reaction of Cys-SOH with 3-hydroxy-5,5-dimethyl-2-cyclohexen-1-one, the enol tautomer of 5,5-dimethyl-1,3-cyclohexadione (dimedone), have been studied using BD(T), CCSD(T)...

Structural features of hydrogen thioperoxide (oxadisulfane, H-S-O-H) and of alkanesulfenic acids (R-S-O-H; R = CH(3), CH(2)CH(3), CH(2)CH(2)CH(3), CH(CH(3))(2), C(CH(3))(3), CF(3), CCl(3)) and the mechanisms of their dehydrative cyclocondensation to the respective sulfinothioic acid (H-(S═O)-S-H) and alkyl alkanethiosulfinates (R-(S═O)-S-R) have be...

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

The singlet-triplet gap and the mechanism of 1,2-cycloaddition of singlet 1,3-dioxol-2-ylidene (S-1) to ethene, (E)-2-butene, (Z)-2-butene, 2,3-dimethyl-2-butene, (E)-2,2,5,5-tetramethyl-3-hexene, (E)-1,2-dicyanoethene, (Z)-1,2-dicyanoethene, tetracyanoethene, (E)-1,2-difluoroethene, (Z)-1,2-difluoroethene, tetrafluoroethene, and tetrachloroethene...

[1333-82-0] CrO3 (MW 99.99)

Electronic structures, partial atomic charges, singlet-triplet gaps (Delta E ST), substituent effects, and mechanisms of 1,2-rearrangements of 1,3-oxazol-2-ylidene ( 5) and 4,5-dimethyl- ( 6), 4,5-difluoro- ( 7), 4,5-dichloro- ( 8), 4,5-dibromo- ( 9), and 3-methyl-1,3-oxazol-2-ylidene ( 10) to the corresponding 1,3-oxazoles have been studied using...

The relative energies and structures of 2-pyrimidinethiol (1), 4-methyl-2-pyrimidinethiol (3), 5-methyl-2-pyrimidinethiol (5), and 4,6-dimethylpyrimidinethiol (7), and their dimers, disulfides, sulfenyl radicals, and tautomers have been studied using restricted and unrestricted ab initio theory, density functional theory, complete basis set methods...

The conformational analysis of cycloheptane (1), oxacycloheptane (2), 1,2-dioxacycloheptane (3), 1,3-dioxacycloheptane (4), and 1,4-dioxacycloheptane (5) has been carried out using B3LYP, CCD, CCSD, and QCISD with the 6-311+G(d,p) and cc-pVDZ basis sets. The twist chair conformers are predicted to be lower in energy than their corresponding boat an...

[7778-50-9] Cr2K2O7 (MW 294.20) InChI = 1S/2Cr.2K.7O/q;;2*+1;;;;;;2*-1InChIKey = KMUONIBRACKNSN-UHFFFAOYSA-N(reagent for converting alcohols to aldehydes, carboxylic acids, and ketones)Physical Data: mp 398 °C; d 2.676 g cm−3.Solubility: H2O (4.9 g/100 mL at 0 °C), DMSO, polyethylene glycol (PEG).Form Supplied in: red crystals.Handling, Storage, an...

[4112-22-5] C4H6CrO6 (MW 202.10) InChI = 1S/2C2H4O2.Cr.2O/c2*1-2(3)4;;;/h2*1H3,(H,3,4);;;/q;;+2;;/p-2InChIKey = GVLKDDUPMFWUKV-UHFFFAOYSA-L(oxidizing agent for carbon–hydrogen bonds, carbon–carbon double bonds, macrocyclic lactones, and alcohols)Physical Data: mp 30.5 °C.Solubility: sol CCl4, Ac2O, HOAc; slowly oxidizes many solvents.Purification:...

Singlet–triplet gaps (S–T, ΔEST), structural parameters, intramolecular CH insertion reactions, intramolecular NH insertion reactions, intermolecular CH insertion reactions, and intramolecular 1,2-rearrangements of aminocyanocarbenes (NCCNX2, X = H, CH3, CF3) have been studied using restricted and unrestricted CCD, CCSD, QCISD, B3LYP, and MP2 metho...

The [2,3]-sigmatropic rearrangements of hydrogen and alkyl 3-propenyl sulfoxides (R = H, CH3, CF3, CCl3) to the corresponding 3-propenyl sulfenates have been examined computationally using HF, MP2, and B3LYP with the 6-31G(d), 6-31+G(d,p), 6-311+G(d,p), 6-311+G(2d,2p), 6-311+G(3d,2p), and cc-pVTZ basis sets. The relative energies (Erel) of the resp...

Density functional theory (BLYP, B3LYP, B3P86, B3PW91) with the 6-31+G(d,p), 6-311+G(d,p), and cc-pVTZ basis sets has been used to calculate structural parameters, relative energies, and vibrational spectra of 2-pyrimidinethiol (1) and 2(1H)-pyrimidinethione (2) and their hydrogen-bonded homodimers (C(2) 3, C(2h) [4](double dagger), C(2h) 5), monoh...

The equilibrium geometries and relative energies of the chair, twist, and boat conformations of cis- and trans-4-bromo-4-silathiacyclohexane 1-oxide and 4,4-dibromo-4-silathiacyclohexane 1-oxide have been calculated at the B3LYP/6-311G(d,p) and MP2/6-311+G(d,p) theoretical levels. The axial (SO) chair conformers of the sulfoxides are of lower energ...

The relative energies and structures of the chair, twist, and boat conformations of stannacyclohexane, 1-methylstannacyclohexane, and 1,1-dimethylstannacyclohexane have been investigated using density functional theory (DFT) (BLYP, B3LYP, B3P86, B3PW91) and hybrid Hartree-Fock/DFT (BH and HLYP) methods with the SDD basis set. The five levels of the...

Second-order Møller–Plesset theory (MP2) and density functional theory (B3LYP) with the 6-311G(d,p) and 6-311+G(d,p) basis sets have been used to calculate the equilibrium geometries and relative energies of the chair, twist, and boat conformations of 4-chloro-4-silathiacyclohexane 1-oxide and 4,4-dichloro-4-silathiacyclohexane 1-oxide. The chair c...

B3LYP/6-311+G(d,p) has been used to calculate the relative energies and geometrical parameters of the respective reactants, transition states, and cycloadducts from the cycloadditions of azomethine ylide and ethene, (Z)-2-butene, and (E)-2-butene. The half-chair (envelope) transition state structures are consistent with a synchronous concerted cycl...

The use of second-order MoØller-Plesset theory (MP2) to calculate the equilibrium geometries and relative energies of the chair, 1,4-twist, 1,4-boat, and 2,5-boat conformations of thiocyclohexane 1-oxide (tetrahydro-2H-thiopyran 1-oxide) and 4,silathiacyclohexane 1-oxide, is discussed. The axial chair conformer are more stable than the correspondin...

Stereoelectronic hyperconjugative interactions and the relative energies of conformers and transition states of 2-, 3-, and 4-silathiacyclohexane were calculated at the B3LYP/6–311+G(d,p) level of theory. The chair conformer of 2-silathiacyclohexane is 15.4 and 15.9 kcal mol−1 (1 kcal = 4.184 kJ), respectively, lower in energy than the chair confor...

Stereoelectronic hyperconjugative interactions, geometrical parameters, and relative energies of conformations and isomers of silacycloalkanes have been calculated at the B3LYP/6-311+G(d,p) level of theory. The chair conformer of silacyclohexane was calculated to be 3.89, 4.82, and 5.18 kcal/mol more stable than the respective 1,4-twist conformer,...

The sila-Pummerer rearrangement of organosilicon cyclic sulfoxides proceeds via the two transition states, the first one with pentacoordinated Si that connects the reagent and the intermediate ylide and the second one that connects the ylide and the product of rearrangement.

Ab initio molecular orbital theory and density functional theory (DFT) with the 6-31G(d), 6-31G(d,p), 6-31+G(d,p), and 6-311+G(d,p) basis sets have been used to study the mechanism of conformational interconversion of 5,5-dimethyl-1,2,3-trithiacyclohexane (5,5-dimethyl-1,2,3-trithiane). The relative energies, enthalpies, entropies, free energies, a...

Ab initio theory, density functional theory (DFT) and Møller–Plesset perturbation theory (MP2) with the 6–31G(d), 6–31++G(d), 6–31G(d,p), 6–31+G(d,p), 6–31++G(d,p), 6–311G(d,p) and 6–311+G(d,p) basis sets were used to study stereoelectronic hyperconjugative interactions and the mechanism of the chair–chair conformational interconversion in 1,2,3-tr...

Ab initio molecular orbital theory with the LANL2DZ, 3-21G, 6-31G(d), 6-31+G(d), 6-31+G(d,p), 6-311+G(d,p),6-31G(2d), 6-31G(3d), and 6-311G(d,p) basis sets and density functional theory (B3P86, B3LYP, B3PW91) have been used to calculate the structures, relative energies, enthalpies, entropies, and free energies of the chair, 1,4-twist, and 2,5-twis...

Ab initio molecular orbital theory with the 6-31G(d), 6-31G(d,p), 6-31+G(d), 6-31+G(d,p), 6-31+G(2d,p), 6-311G(d), 6-311G(d,p), and 6-311+G(2d,p) basis sets and density functional theory (BLYP, B3LYP, B3P86, B3PW91) have been used to locate transition states involved in the conformational interconversions of 1,4-dithiacyclohexane (1,4-dithiane) and...

Aldehydes by oxidation of terminal olefins with chromyl chloride: 2,4,4‐trimethylpentanal catalyst: 158 g. (1.02 moles) of freshly distilled chromyl chloride product: 2,4,4‐trimethylpentanal product: 4,4‐Dimethyl‐2‐neopentylpentanal product: 2‐Phenylpropanal product: Diphenylacetaldehyde

A computational study of conformations and conformers of 1,3-Dithiane was conducted using ab initio molecular orbital theory and density functional theory. Intrinsic reaction coordinate (IRC, minimum energy path) calculations were used to connect the enantiomers of the 1,4-twist conformer via the 2, 5-boat transition state. The importance of geomet...

Ab initio molecular orbital theory with the 6-31G(d), 6-31G(2d), 6-31+G(d), 6-31G(d,p), 6-31+G(d,p), and 6-311G(d,p) basis sets and the hybrid density functionals B3LYP, B3P86, and B3PW91 have been used to calculate the optimized geometries and relative energies of the chair, half-chair, sofa, twist, and boat structures of 2-thiaoxacyclohexane (1,2...

The structures and energies of axial and equatorial conformers and rotamers of 4-substituted tetrahydro-2H-thiopyran-1,1-dioxides (tetrahydrothiopyran-1,1-dioxides, thiacyclohexane-1,1-dioxides, thiane-1,1-dioxides, and 1,1-dioxothianes; CH3, CH2OH, CHO, COCH3, CN, F, Cl, Br, and OCOCH3) were calculated using the hybrid density functionals B3LYP, B...

Ab initio molecular orbital theory with the 6-31G(d), 6-31G(d,p) and 6-31G+G(d) basis sets and the hybrid density functionals B3P86, B3LYP, and B3PW91 have been used to study the energy differences (ΔE), conformational enthalpies (ΔH0), entropies (ΔS0), and free energies (ΔG0) and structural parameters of conformers of 1,3-dioxane (1,3-dioxacyclohe...

Ab initio molecular orbital theory with the 6-31G(d), 6-31+G(d), 6-31G(d,p), 6-311G(d,p), 6-311+G(d,p), 6-31G(2d), 6-311G(2d), and 6-311G(2d,p) basis sets have been used to calculate the conformational enthalpies (ΔH°), entropies (ΔS°), and free energies (ΔG°) of the axial and equatorial conformers of 2-methyl-, 3-methyl-, and 4-methyltetrahydro-2H...

Ab initio theory with the 3-21G, 6-31G(d), 6-31G(d,p), 6-311G(d,p), 6-31+G(d), and 6-311+G(d,p) basis sets and density functional theory (SVWN, pBP, BLYP), including the hybrid density functional methods B3LYP, B3PW91, and B3P86, have been used to calculate the energies of the chair, half-chair, sofa, twist, and boat conformers of tetrahydro-2H-pyr...

Ab initio theory and density functional theory (B3LYP) have been used to calculate the geometry optimized structures, configurational isomer energy differences (ΔE), and the configurational enthalpies (ΔH0), entropies (ΔS0), and free energies (ΔG0) of 4-alkyl equatorial tetrahydro-2H-thiopyran-1-oxides (tetrahydrothiopyran-1-oxides, thiacyclohexane...

(CrO3) [1333-82-0] CrO3 (MW 99.99) InChI = 1S/Cr.3O InChIKey = WGLPBDUCMAPZCE-UHFFFAOYSA-N (SiO2) [60676-86-0] O2Si (MW 60.09) InChI = 1S/O2Si/c1-3-2 InChIKey = VYPSYNLAJGMNEJ-UHFFFAOYSA-N (reagent for oxidizing alcohols to carbonyl compounds)Physical Data: CrO3 mp 196 °C; d 2.70 g cm−3.Preparative Methods: the reagent is prepared by addition of si...

[7778-12-0] Cr2Na2O7 (MW 298.02) InChI = 1S/2Cr.2Na.7O/q;;2*+1;;;;;;2*-1InChIKey = KIEOKOFEPABQKJ-UHFFFAOYSA-N(reagent for oxidizing alkylaromatics to carboxylic acids, oxidizing benzylic methylene groups to carbonyl groups, oxidizing alkenes to form α,β-unsaturated compounds, and for converting alcohols to carbonyl compounds)Physical Data: mp (los...

[15306-22-6] C20H23CoN3O2 (MW 396.36) InChI = 1S/C20H25N3O2.Co/c24-19-9-3-1-7-17(19)15-22-13-5-11-21-12-6-14-23-16-18-8-2-4-10-20(18)25;/h1-4,7-10,15-16,21,24-25H,5-6,11-14H2;/q;+2/p-2/b22-15+,23-16+;InChIKey = DFUNVHCIQIWEIL-YXEBPMGASA-L(catalyst for the homogeneous oxygenation of phenols with dioxygen in organic media)Alternate Name: Co(Salpr).So...

[109201-26-5] C6H10Cr2N4O7 (MW 354.20) InChI = 1S/2C3H4N2.2Cr.7O/c2*1-2-5-3-4-1;;;;;;;;;/h2*1-3H,(H,4,5);;;;;;;;;/q;;;;;;;;;2*-1/p+2InChIKey = LBMPYYBPKIVDBH-UHFFFAOYSA-P(mild selective reagent for the oxidation of allylic and benzylic alcohols to the corresponding carbonyl compounds)Alternate Name: IDC.Physical Data: mp 130–131 °C; nonhygroscopic;...

(CrO3) [1333-82-0] CrO3 (MW 99.99) InChI = 1S/Cr.3O InChIKey = WGLPBDUCMAPZCE-UHFFFAOYSA-N (quinoline) [91-22-5] C9H7N (MW 129.16)(mild selective reagent for the oxidation of primary and secondary alcohols to the corresponding carbonyl compounds under basic conditions)Preparative Methods: the reagent is prepared either in solid solid form prior to...

[109-77-3] C3H2N2 (MW 66.07) InChI = 1S/C3H2N2/c4-2-1-3-5/h1H2InChIKey = CUONGYYJJVDODC-UHFFFAOYSA-N(active methylene reagent useful for condensation reactions, for preparing synthetic intermediates, and for the synthesis of heterocycles)Alternate Names: propanedinitrile; dicyanomethane; malonic (acid) dinitrile; propiodinitrile; methylene cyanide;...

[1189-85-1] C8H18CrO4 (MW 230.22) InChI = 1S/2C4H9O.Cr.2O/c2*1-4(2,3)5;;;/h2*1-3H3;;;/q2*-1;+2;; InChIKey = PNWJTIFZRHJYLK-UHFFFAOYSA-N [110-86-1] C5H5N (MW 79.10) InChI = 1S/C5H5N/c1-2-4-6-5-3-1/h1-5H InChIKey = JUJWROOIHBZHMG-UHFFFAOYSA-N (reagent for oxidizing alcohols and silyl ethers to aldehydes and ketones)Alternate Name: tert-butyl chromate...

[1189-85-1] C8H18CrO4 (MW 230.22) InChI = 1S/2C4H9O.Cr.2O/c2*1-4(2,3)5;;;/h2*1-3H3;;;/q2*-1;+2;;InChIKey = PNWJTIFZRHJYLK-UHFFFAOYSA-N(selectively oxidizes allylic methylene groups to carbonyl groups; oxidizes alcohols to aldehydes and ketones)Alternate Names: tert-butyl chromate.Physical Data: red crystals; oil at rt; mp −5 to 0 °C.Solubility: sol...

[26412-88-4] C10H10CrN2O3 (MW 258.22) InChI = 1S/2C5H5N.Cr.3O/c2*1-2-4-6-5-3-1;;;;/h2*1-5H;;;;/q;;+2;;2*-1InChIKey = LYUSQVMBCUPELV-UHFFFAOYSA-N(reagent for oxidizing alcohols to carbonyl compounds)Alternate Names: Collins reagent; chromium(VI) oxide–pyridine.Solubility: sol CH2Cl2; (Z)-1,2-dichloroethylene; pyridine; CHCl3.Form Supplied in: red cr...

[14977-61-8] Cl2CrO2 (MW 154.92) InChI = 1S/2ClH.Cr.2O/h2*1H;;;/q;;+2;;/p-2InChIKey = AHXGRMIPHCAXFP-UHFFFAOYSA-L(reagent for converting alkenes to aldehydes, oxiranes, ketones, chlorohydrins, α-chloro ketones, vicinal chloroacetates, and α-hydroxy ketones, and for oxidizing alkylaromatics to alcohols, aldehydes, and ketones)Alternate Names: dichlo...

(R = Et) [105-56-6] C5H7NO2 (MW 113.13)

[372-09-8] C3H3NO2 (MW 85.06) InChI = 1S/C3H3NO2/c4-2-1-3(5)6/h1H2,(H,5,6)InChIKey = MLIREBYILWEBDM-UHFFFAOYSA-N(active methylene compound for preparing α,β-unsaturated nitriles and esters, for carbolactonization of alkenes to α-cyano γ-lactones, and for converting trans-1,2-bromohydrins to cis-1,2-diols)Physical Data: mp 70–71 °C.Solubility: sol H...

Ab initio molecular orbital theory with the 6-31G(d), 6-31+G(d), 6-31G(d,p), and 6-31G(2d) basis sets has been used to calculate the geometry optimized structures and the relative energies (ΔE) of the rotamers of the chair conformers of 3-substituted equatorial tetrahydro-2H-thiopyran-1-oxides (tetrahydrothiopyran-1-oxides, thiacyclohexane-1-oxides...

Ab initio Hartree–Fock calculations using the 6-31G(d), 6-31G(2d), 6-31G(d,p), 6-311G(d,p), 6-31+G(d), and 6-311+G(d,p) basis sets, second-order Møller–Plesset perturbation theory (MP2) using the same basis sets, and density functional theory [SVWN/DN∗, SVWN/DN∗∗, pBP/DN∗, pBP/DN∗∗, BLYP/6–31G(d), B3BLYP/6–31G(d)] were used to calculate the geometr...

Ab initio molecular orbital theory using the 3-21G(∗), 6-31G∗, 6-31G∗∗, 6-311G∗∗ basis sets, Møller-Plesset perturbation theory [MP2/3-21G(∗)//3-21G(∗), MP2/6-31G∗//6-31G∗, MP2/6-31G∗∗//6-31G∗∗, MP2/6-311G∗∗//6-311G∗∗], and density functional theory (pBP/DN∗∗) were used to calculate the geometries and energies of dihydrodioxins (3,4-dihydro-1,2-dio...

Ab initio 6-31G(d) and MP2/6-31G(d)//6-31G(d) methods were used to calculate the energies of the rotamers of the chair conformers of alkylcyclohexanes and trimethylsilylcyclohexane. The MP2/6-31G(d)//6-31G(d) calculated conformational energies ( or A values, in kcal/mol) of the alkylcyclohexanes (Me = 1.96; Et = 1.80; Pr = 1.73 iso-Pr = 1.60; t-Bu...

The kinetics of the base-catalyzed permanganate oxidation of benzaldehyde have been reexamined. The rate is proportional to the first power of the aldehyde and permanganate concentrations, and there are terms that are zero order, first order, and second order in hydroxide ion. The reaction has an isotope effect, and the effect of substituents gives...

Ab initio Hartree–Fock and Density Functional Theory calculations were used to obtain the geometries and relative energies of the rotamers in the chair conformations of 2-alkyltetrahydro-2H-pyrans and 2-(trimethylsilyl)tetrahydro-2H-pyran. The MP2/6-31G*//6-31G* conformational energies (−ΔG°or A values, kcal/mol) of the 2-alkyltetrahydro-2H-pyrans...

Ab initio 6-31G∗ and 6-31G∗∗ basis sets and density functional theory (pBP/DN∗∗) were used to calculate the geometry of the chair conformer of tetrahydro-2H-thiopyran (tetrahydrothiopyran, thiacyclohexane, thiane). 6-31G∗ geometry optimization and MP2/6-31G∗//6-31G∗ single point energy methods were used to calculate the relative energies and confor...

Ab initio HF/6-31G∗ and MP2/6-31G∗//HF/6-31G∗ methods were used to calculate the relative energies of the rotamers in the chair conformations of 3-alkyltetrahydro-2H-pyrans (tetrahydropyrans, oxacyclohexanes, oxanes; CH3, C2H5, i-C3H7, t-C4H9, neo-C5H11) and 3-(trimethylsilyl)tetrahydro-2H-pyran; Si(CH3)3). The MP2/6-31G∗//HF/6-31G∗ conformational...

Ab initio 6–31G* and MP2/6–31G*// 6–31G* methods and density functional (pBPDN**) theory were used to calculate the geometries and relative energies of the chair, boat, and twist-boat conformations of tetrahydro-2H-thiopyrans (tetrahydrothiopyrans, thiacyclohexanes, thianes). The chair conformation of thiacyclohexane is 5.3 and 8.0 kcal mol−1, resp...

Ab initio 6–31G* and MP2/6–31G*//6–31G* methods were used to calculate the relative energies of the rotamers in the chair conformations of 4-alkyltetrahydro-2H-thiopyrans (tetrahydrothiopyrans, thiacyclohexanes, thianes; CH3, C2H5, i-C3H7, t-C4H9, neo-C5H11, SiMe3). The MP2/6–31G*//6–31G* conformational energies (−ΔG° or A values, kcal mol-1) of th...

Optimized geometries and energies for 3,4-dihydro-1,2-dithiin (1), 3,6-dihydro-1,2-dithiin (2), 4H-1,3-dithiin (3), and 2,3-dihydro-1,4-dithiin (4) were calculated using ab initio 6-31G* and MP2/6-31G*//6-31G* methods. At the MP2/6-31G*//6-31G* level, the half-chair conformer of 4 is more stable than those of 1, 2, and 3 by 2.5, 3.5, and 3.6 kcal/m...

A convenient 1-pot method for the prepn. of 2-substituted 5-amino-4-cyano-1,3-oxazoles from carboxylic acids and aminomalononitrile tosylate is reported.

Optimized geometries and total energies for 3,4-dihydro-1,2-dioxin (1), 3,6-dihydro-1,2-dioxin (2), 4H-1,3-dioxin (1,3-diox-4-ene, 3), and 2,3-dihydro-1,4-dioxin (1,4-dioxene, 4) were calculated using ab initio 3-21G, 6-31G*, and MP2/6-31G*//6-31G* methods. The half-chair conformers of 1 (C1), 2 (C2), 3 (C1), and 4 (C2) are more stable than their r...

Thionation reaction of 2,3-diaroylbicyclo[2.2.1]hepta-5-enes using in situ generated B2S3 (bis-trialkyltin sulfide or bis-trimethylsilyl sulfide reacted with BCl3 in toluene) gave [3,4] and [3,5] sigmatropic rearrangement products.

In the crystal structure of the title compound, C18H18N4O6.2K(2)O, the [1,3]oxazolo[5,4-d]pyrimidine ring is planar and seems to possess a pi-stacking interaction with the phenyl ring of the ester group.

The crystal structure of the title compound, C30H24Cl2S2, (I), is described and compared with that of (1Z,3Z)-1,4-diphenyl-1,4-bis(p-tolylmethylthio)buta-1,3-diene, (II). The 1,3-butadiene moiety in compound (I) has a planar s-trans conformation with the planes of the two phenyl rings tilted 32.8 degrees from the 1,3-butadiene plane. The relatively...

2-endo-3-endo- and 2-endo-3-exo-bis(2, 4, 6-trimethylphenyl)]methanoylbicyclo[2.2.1]hept-5-ene (6 and 7) rearrange in the presence of trimethylsilyl trifluoromethanesulfonate (TMSOTf) and bis(trimethylsilyl) sulfide to 3-(2, 4, 6-trimethylphenyl)-4-[(2, 4, 6-trimethylphenyl)methyl]-2-oxabicyclo[3.3.0]octa-3, 7-diene (8) and 3-(2, 4, 6-trimethylphen...

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and...

The crystal structure of 3-benzyl-5-phenyl-2-p-tolylthiophene, C24H20S, is described. The thiophene ring in the title compound is planar and its structural properties are very similar to those of thiophene. The thiophene ring in compound (1) is planar as are the phenyl rings. The structure of the thiophene ring in compound (1) is very similar to th...

The crystal structure of (1Z,3Z)-1,4-diphenyl-1,4-bis-(p-tolylmethylthio)-1,3-b utadiene (1), C32H30S2, is described. Compound (1) has an s-trans conformation. The single bond length, C(2)--C(2'), in compound (1) of 1.432 (5) A is shorter than the C(3)--C(4) single bond (1.48 A) in 1,3-butadiene and the double-bond length, C(1)--C(2), of 1.350 (3)...

The crystal structure of (1Z,3Z)-1,4-diphenyl-1,4-bis-(p-tolylmethylthio)-1,3-butadiene (1), C32H30S2, is described. Compound (1) has an s-trans conformation. The single bond length, C(2)-C(2'), in compound (1) of 1.432 (5) Angstrom is shorter than the C(3)-C(4) single bond (1.48 Angstrom) in 1,3-butadiene and the double-bond length, C(1)-C(2), of...

The crystal structure of bis(tert-butylsulfonyl) disulfide, C8H18O4S4, is described and compared with oxides of other polysulfanes. The SO2-S bond distance is longer than that of S-S and there is considerable double-bond character along the S-O bonds.

S-(2-Propenyl) 2-propene-1-sulfinothioate (allicin), which is one of the constituents of freshly crushed garlic (garlic homogenate), was synthesized, and its stability in blood, ethyl acetate, methanol, simulated gastric fluid (SGF, pH 1.2), simulated intestinal fluid (STF, pH 7.5), and water (pH 1.2 and 7.5) and under simulated digestive condition...

The preparation of acetyl alkyl disulfides 2, which are key intermediates for the synthesis of alkyl hydrodisulfides 1, from disulfides is described. Disulfides are oxidized to sulfinothioic acid S-esters (thiosulfinates) which thioalkylate thioacetic acid to form acetyl alkyl disulfides 2.

Optimized geometries and total energies for the conformers of 3,6-dihydro-1,2-dithiin (2) and 3,6-dihydro-1,2-dioxin (3) were calculated at several ab initio MO levels: RHF/3-21G(*), RHF/6-31G*, MP2/6-31G*, and MP2/6-31G*/ /RHF/3-21G(*). For the dioxin, in addition to the above levels the corresponding nonextended basis sets ab initio methods were...

Addition of phenylmethanethiols (benzylthiols), including (2-furyl)methanethiol, to butadiynes in potassium hydroxide/dimethyl sulfoxide affords the corresponding 2,5-diaryl-3-(phenylmethyl)thiophenes.

The chemical ionization (CI) and electron impact (El) mass spectra of six S-1-chloroalkyl alkanesulfonothioates (thiosulfonates) are reported.

The chemical ionization (CI) and electron impact (El) mass spectra of six S‐1‐chloroalkyl alkanesulfonothioates (thiosulfonates) are reported.

1,4-Diphenyl- and 1,4-bis(4-chlorophenyl)-1,4-butanediones (3 and 4), as well as 1-phenyl-, 1-(4-chlorophenyl)-, and 1-(4-methoxyphenyl)-1,4-pentanediones (7-9) react with bis(tributyltin), bis(tricyclohexyltin), and/or bis(triphenyltin) sulfide in the presence of boron trichloride to give, 2,5-diaryl- or 5-methyl-2-arylthiophenes. 1,8-Diphenyl-1,7...

(1E,3E)-4-Amino-3-cyano-4-methoxy-1-phenyl-2-azabutadiene (2) reacts with 2-methoxypropene in refluxing methylbenzene in the presence of catalytic pyridinium p-toluenesulfonate (PPTS) to give 2-cyano-5,5-dimethyl-3-methoxy-6-phenyl-4,5-dihydro-1,4-diazabenzene (5). Similarly, 2-aza-1,3-butadiene 2 reacts with triethyl orthoformate and triethyl orth...

The oxidation and reduction potentials for eight imidazole-2-thiols [imidazole-2-thiol (1a), 1-methyl-(1b), 4,5-dimethyl- (1c), 1,4,5-trimethyl- (1d), 4,5-diphenyl- (1e), benz- (1f), 5-methylbenz- (1g), and 5-nitrobenzimidazole-2-thiol (1h)] have been determined in ethanenitrile-hydrogen chloride solution. Substituent effects on E(ox) are observed...