Reaction between tetraneopentylzirconium and 2,6-di-tert-butyl-4-methylphenol. A homogeneous analog of a metal complex-surface proton transfer reaction

1993 ◽  
Vol 12 (10) ◽  
pp. 4204-4206 ◽  
Author(s):  
John B. Miller ◽  
Jeffrey Schwartz ◽  
Kevin M. Carroll
Keyword(s):  
Proton Transfer ◽  
Metal Complex ◽  
Transfer Reaction ◽  
Complex Surface ◽  
Proton Transfer Reaction ◽  
Tert Butyl

A 2-Azapentadienyl Carbanion: a Nonstereospecific Electrocyclization

1975 ◽  
Vol 53 (3) ◽  
pp. 355-365 ◽  
Author(s):  
D. H. Hunter ◽  
R. P. Steiner
Keyword(s):  
Proton Transfer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Butyl Alcohol ◽  
Open Chain ◽  
Tert Butyl ◽  
Tert Butyl Alcohol ◽  
Cis And Trans ◽  
Protic Media

Treatment of 1,3,5-triphenyl-4-aza-1,3-pentadiene under selected basic conditions leads to either isomerization among the azapentadienes or to cyclization. Analysis of the products from reaction under aprotic conditions (LiTMP in THF) suggested that the open-chain delocalized carbanion exists in both the W and sickle forms. The open-chain anions were observed to electrocyclize in a nonstereospecific manner to produce a 1:1 mixture of cis- and trans-2,4,5-triphenyl-1-pyrrolines. Reaction in protic media (methanol and tert-butyl alcohol) produced a 1,5-proton transfer as well as cyclization. The details of the 1,5-proton transfer reaction were elucidated using methanol-O-d and the collapse preferences and intramolecularity in this medium were determined.

scholarly journals Identifying volatile in vitro biomarkers for oral bacteria with proton-transfer-reaction mass spectrometry and gas chromatography–mass spectrometry

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Kajsa Roslund ◽  
Markku Lehto ◽  
Pirkko Pussinen ◽  
Kari Hartonen ◽  
Per-Henrik Groop ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Proton Transfer ◽  
Transfer Reaction ◽  
Proton Transfer Reaction ◽  
Oral Bacteria ◽  
Gas Chromatography Mass Spectrometry ◽  
Volatile Analysis ◽  
Bacterial Volatiles

AbstractWe have measured the volatile fingerprints of four pathogenic oral bacteria connected to periodontal disease and dental abscess: Porphyromonas gingivalis (three separate strains), Prevotella intermedia, Prevotella nigrescens and Tannerella forsythia. Volatile fingerprints were measured in vitro from the headspace gas of the bacteria cultured on agar. Concrete identification of new and previously reported bacterial volatiles were performed by a combination of solid phase microextraction (SPME) and offline gas chromatography–mass spectrometry (GC–MS). We also studied the effect of the reduced electric field strength (E/N) on the fragmentation patterns of bacterial volatiles in online proton-transfer-reaction time-of-flight mass spectrometry (PTR-ToF-MS). We aimed to discover possible new biomarkers for the studied oral bacteria, as well as to validate the combination of GC–MS and PTR-MS for volatile analysis. Some of the most promising compounds produced include: 1-Methyl-1,2,3,4-tetrahydroisoquinoline (1MeTIQ), indole, and a cascade of sulphur compounds, such as methanethiol, dimethyl disulphide (DMDS) and dimethyl trisulphide (DMTS). We also found that several compounds, especially alcohols, aldehydes and esters, fragment significantly with the PTR-MS method, when high E/N values are used. We conclude that the studied oral bacteria can be separated by their volatile fingerprints in vitro, which could have importance in clinical and laboratory environments. In addition, using softer ionization conditions can improve the performance of the PTR-MS method in the volatile analysis of certain compounds.

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