Elucidation of thermal reactions by variable temperature photoelectron spectral detection of reactive intermediates. The UV photoelectron spectra of transient fulveneketene, fulvenethioketene, A ketoketene, and thiobenzpropiolactone

Schulz, Reinhard; Schweig, Armin

doi:10.1016/s0040-4039(01)85881-0

Cited by 36 publications

(27 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…-Benzothiet-2-one (¼ 7-thiabicyclo[4.2.0]octa-1,3,5-trien-8-one; 1) has been shown to be a transient intermediate in many photochemical and thermal organic reactions. This product can be obtained by flash vacuum thermolysis (FVT) of 2-sulfanylbenzoic acid or benzo [b]thiophene-2,3-dione at 600 -6108 [1], as well as photolytically, starting either from 4H-1,2,3-benzothiadiazin-4-one [2] or from 2-phenyl-4H-3,1-benzoxathiin-4-one [3]. 1 is stable only below À 208 in the solid state; above this temperature, rapid polimerization, as well as partial di-and trimerization takes place.…”

mentioning

confidence: 99%

“…Both thiet-2-ones were characterized by IR, 1 H-and 13 C-NMR spectra [4], and, additionally, UV-photoelectron spectra of 1 were registered [1]. Although the more stable ring in 1 could exist in equilibrium with its ring-opened valence tautomer, the latter has not been detected until now.…”

mentioning

confidence: 99%

“…Although the more stable ring in 1 could exist in equilibrium with its ring-opened valence tautomer, the latter has not been detected until now. In contrast, the open keto-ketene form of the dioxygen analogue has been characterized by photoelectron spectra [1].…”

mentioning

confidence: 99%

See 2 more Smart Citations

Flash Vacuum Thermolysis of 4H‐3,1‐Benzoxathiin‐4‐thione: UV‐Photoelectron Spectroscopy Characterization and Quantum Chemistry Studies

Drewnowski¹,

Chrostowska²,

Leśniak³

et al. 2008

Helvetica Chimica Acta

View full text Add to dashboard Cite

The mechanism of the reaction of 4H-3,1-benzoxathiin-4-thione (3) under flash vacuum thermolysis conditions has been studied by UV-photoelectron spectra. It was shown that in the first step of the reaction at 4008 3 underwent the Schçnberg -Newman -Kwart rearrangement to give 4H-1,3-benzodithiin-4-one (6). Increasing of the temperature to 6508 resulted in the elimination of thioformaldehyde and the formation of benzothiet-2-one (1). Subsequent elevation of the temperature prompted presumably the ring opening of 1 to (6-thioxocyclohexa-2,4-dien-1-ylidene)methanone (7) (at 6808), which at 7008 eliminated CO and underwent a Wolff-type ring contraction to give (cyclopenta-2,4-dien-1-ylidene)methanethione (2). UV-Photoelectron spectra were recorded at different steps of the reaction and analyzed considering the theoretical evaluation of ionization potentials.Introduction. . 1 is stable only below À 208 in the solid state; above this temperature, rapid polimerization, as well as partial di-and trimerization takes place. Above 8008, the loss of CO from 1 and a Wolff-type ring contraction to give (cyclopenta-2,4-dien-1-ylidene)methanethione (2) were mentioned [4] (Scheme 1).It is noteworthy that the analogous 2H-naphtho[2,3-b]thiet-2-one was successfully isolated and identified at room temperature [4]. Both thiet-2-ones were characterized by IR,

show abstract

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Flash Vacuum Thermolysis of 4H‐3,1‐Benzoxathiin‐4‐thione: UV‐Photoelectron Spectroscopy Characterization and Quantum Chemistry Studies

Drewnowski¹,

Chrostowska²,

Leśniak³

et al. 2008

Helvetica Chimica Acta

View full text Add to dashboard Cite

show abstract

“…This article must therefore be hereby marked "advertisement" in accordance with 18 (17,18) found that thianaphthene-1,1-dioxide (19), on pyrolysis at 1000'C, underwent a very unusual rearrangement to give benzo [b]thiete (20). 22 (14) have reported that irradiation of 2-phenyl-3,1-benzoxathian-4-one (26) in an infrared cell at 77 K gave a product whose spectrum was in accord with that expected for 2-thiobenzpropiolactone (27).…”

mentioning

confidence: 99%

“…When the cell was warmed to -400C, the product isolated was 28. Recently, Schulz and Schweig (19) have observed that the introduction of thiosalicylic acid (29) into a photoelectron spectrometer at 600'C gave a spectrum that they assigned to 2-thiobenzpropiolactone (27). We have now found that benzo[bJthiete can be prepared very simply in good yield by the gas-phase pyrolysis of the readily available o-mercaptobenzyl alcohol (21).…”

mentioning

confidence: 99%

Benzocyclobutene— o -xylylene valence tautomerization: Oxygen and sulfur analogs

Mao

Boekelheide

1980

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Gas phase pyrolysis of o-hydroxybenzyl alcohol at 750'C gave o-quinonemethide, which, on isolation, formed a mixture of the corresponding dimer and trimer. However, pyrolysis of o-hydroxy[1(4-pentenyl)Jbenzyl alcohol permitted intramolecular trapping of the intermediate o-quinonemethide, giving 3,4-trimethylene-3,4-dihydrobenzochroman. In contrast, gas phase pyrolysis of o-mercaptobenzyl alcohol readily gave benzo[blthiete in good yield. The pyrolysis makes this interesting highly strained molecule readily available for study and synthetic application. Preliminary results showed that benzol bthiete readily undergoes thermal dimerization, ringopening reactions with nucleophiles, and a variety of DielsAlder reactions.-

show abstract

100 Years of the Wolff Rearrangement

2002

View full text Add to dashboard Cite

The conversion of α‐diazo ketones into ketenes, and products derived therefrom, was discovered by Wolff in 1902. Major applications of the Wolff rearrangement, such as the Arndt−Eistert reaction (homologation of carboxylic acids) and the ring contraction of cyclic ketones, have been with us for some while. Nevertheless, substantial progress has been made recently. The reaction mechanism has been explored by means of matrix isolation, time‐resolved spectroscopy, and computation. Full retention of configuration of the migrating group has been established by using enantioselective chromatography. The Arndt−Eistert reaction has witnessed a renaissance in the field of natural products, in particular β‐amino acids and β‐peptides. Ring‐contracting Wolff rearrangements and ketene cycloadditions have been applied in syntheses of increasingly complex, biologically active target molecules. These accomplishments, as well as unsolved problems, are addressed in the present review. (© Wiley‐VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

show abstract

Elucidation of thermal reactions by variable temperature photoelectron spectral detection of reactive intermediates. The UV photoelectron spectra of transient fulveneketene, fulvenethioketene, A ketoketene, and thiobenzpropiolactone

Cited by 36 publications

References 15 publications

Flash Vacuum Thermolysis of 4H‐3,1‐Benzoxathiin‐4‐thione: UV‐Photoelectron Spectroscopy Characterization and Quantum Chemistry Studies

Flash Vacuum Thermolysis of 4H‐3,1‐Benzoxathiin‐4‐thione: UV‐Photoelectron Spectroscopy Characterization and Quantum Chemistry Studies

Benzocyclobutene— o -xylylene valence tautomerization: Oxygen and sulfur analogs

100 Years of the Wolff Rearrangement

Contact Info

Product

Resources

About