51036-24-9Relevant articles and documents
Ozonation of Xanthene
Matsui, Masaki,Miyamoto, Yoshihiko,Shibata, Katsuyoshi,Takase, Yoshimi
, p. 603 - 604 (1984)
The ozonation of xanthene was studied using an oxygen stream.Ozone attacks the methylene group of xanthene via a 1,3-dipolar insertion reaction to give the hydrotrioxide intermediate, followed by a loss of singlet oxygen to form xanthydrol.The ozonation of xanthydrol gave singlet oxygen, water and xanthone accompanied by autoxidation.
Amphiphilic Reactions by Means of Exceptionally Bulky Organoaluminum Reagents. Rational Approach for Obtaining Unusual Equatorial, Anti-Cram, and 1,4 Selectivity in Carbonyl Alkylation
Maruoka, Keiji,Itoh, Takayuki,Sakurai, Minoru,Nonoshita, Katsumasa,Yamamoto, Hisashi
, p. 3588 - 3597 (2007/10/02)
Exceptionally bulky, oxygenophilic organoaluminum reagents, methylaluminum bis(2,6-di-tert-4-alkylphenoxide) (MAD and MAT), have been successfully utilized for stereoselective activation of carbonyl moiety.Combination of MAD or MAT with carbon nucleophiles such as organolithiums or Grignard reagents generates a new amphiphilic reaction system in which the alkylation may be interpreted as the nucleophilic addition of a reactive organometallic compound to an electrophilically activated carbonyl substrate in order to account for the regio- and stereochemical consequences.In contrast to the ordinary alkylations, the amphilic alkylation disclosed herein would be categorized into the new, yet unexplored class of alkylation that exhibits high chemoselectivity to carbonyl compounds, and more significantly it allows excellent equatorial and anti-Cram selectivity in carbonyl alkylations, hitherto difficult by the existing methodologies.Further, unusual conjugate addition of organolithium reagents to α,β-unsaturated carbonyl compounds has been accomplished by using the amphiphilic reaction system.
Methyl-Substituted Poly(vinylnaphthalene) as a Reversible Singlet Oxygen Carrier
Saito, Isao,Nagata, Ryu,Matsuura, Teruo
, p. 6329 - 6334 (2007/10/02)
Methyl-substituted poly(vinylnaphthalenes) (5a-c) were prepared by radical polymerization of the corresponding vinylnaphthalenes 4a-c.Polymers 5a and 5b have been shown to bind and release singlet molecular oxygen (1O2) reversibly at temperatures between 0 and 35 deg C.Methylene blue sensitized photooxygenation of polymers 5 at 0 deg C produced the corresponding polymer endoperoxides 6 in nearly quantitatve yields.Generation of 1O2 from the thermolysis of polymer endoperoxide 6b at 35 deg C was confirmed by trapping experiments using typical 1O2 acceptors.Kinetic parameters for the thermolyses of 6a and 6b were compared with those for the corresponding monomer endoperoxides.The yield of 1O2 generated from polymer 6b was determined to be as high as 66 +/- 5percent.The synthetic utility of these polymeric endoperoxides as a 1O2 source has been demonstrated in the oxidation of a series of representative substrates.Advantages of using these polymer 1O2 sources are the following: (1) the mild condition for generation of 1O2, (2) utility in nonsolvent systems, and (3) easy removal and resue.
