1961
DOI: 10.1021/jo01351a027
|View full text |Cite
|
Sign up to set email alerts
|

2,2',4,4',6,6'-Hexamethyl-4,4'-bi-4H-pyran1,2

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
1
1
1
1

Citation Types

0
5
0

Year Published

1975
1975
2022
2022

Publication Types

Select...
9

Relationship

0
9

Authors

Journals

citations
Cited by 22 publications
(5 citation statements)
references
References 1 publication
0
5
0
Order By: Relevance
“…Interestingly, TPT• can react with 3 O 2 to give peroxyl radical 48.3 (Scheme ), which is implicated as an intermediate in some oxygenation reactions enabled by TPT + , although others have argued against such an intermediate . Despite the moderate ground state reduction potential enabling TPT• to be returned to the ground state TPT + by a relatively weak oxidant, pyranyl radicals are prone to dimerization adducts 48.1 , which, although reversible for 2,4,6-triarylpyryliums, can deactivate the catalyst in an off-cycle equilibrium. Likewise, nucleophiles can add to the pyrylium core and lead to catalyst degradation via the formation of addition adducts such as 48.2 …”
Section: Pyryliums and Thiapyryliumsmentioning
confidence: 99%
“…Interestingly, TPT• can react with 3 O 2 to give peroxyl radical 48.3 (Scheme ), which is implicated as an intermediate in some oxygenation reactions enabled by TPT + , although others have argued against such an intermediate . Despite the moderate ground state reduction potential enabling TPT• to be returned to the ground state TPT + by a relatively weak oxidant, pyranyl radicals are prone to dimerization adducts 48.1 , which, although reversible for 2,4,6-triarylpyryliums, can deactivate the catalyst in an off-cycle equilibrium. Likewise, nucleophiles can add to the pyrylium core and lead to catalyst degradation via the formation of addition adducts such as 48.2 …”
Section: Pyryliums and Thiapyryliumsmentioning
confidence: 99%
“…Among these are ir-systems such as nitro derivatives of benzene and of related benzenoid hydrocarbons,205,206 fulvenes,207 stilbenes,207 quinones,205 but also cations like the tropylium ion208 or the 2,4,6trimethylpyrylium ion. 209 In the latter instances the reduction is followed by the dimerization of the originally formed neutral radicals. The protonation of 32-which has been prepared under different conditions yields a mixture of the cyclooctatrienes 71 and 72.203,204 In a similar fashion alkylation produces dialkylcyclooctatrienes.…”
Section: Reactions Of Annulene Dianlonsmentioning
confidence: 99%
“…When using the confined TPT-SCNP photocatalyst bearing the pyrene-based ER, a 66% yield of the dimerized product was observed within 24 h. Increasing the concentration to 0.4 M gave moderate improvements (71%, Table S1), while further changes (e.g., altering photocatalyst concentration and light intensity) adversely affected cycloaddition. Pyrylium catalysts are prone to photobleaching and dimerization of the pyranyl radical; , accordingly, longer reaction times did not yield more product, likely because the amount of active pyrylium in solution decreases. Reactions conducted without the TPT-SCNP or in the absence of light yielded no cycloadduct.…”
mentioning
confidence: 99%