- Selective deprotection of phenolic polysulfonates
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Nosylates of phenols can be selectively deprotected by thiocresol anions in DMSO. Successful deprotection can be accomplished in molecules containing aryl-appended halides, ethers, aldehydes, alkanesulfonates or arylsulfonates. Nosylate deprotection is accomplished by the CS bond rupture which is believed to proceed by nucleophilic aromatic substitution.
- Chapman, Erin E.,Langler, Richard F.
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experimental part
p. 19 - 26
(2010/10/04)
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- Selective debenzylation of aromatic benzyl ethers by silica-supported sodium hydrogen sulfate
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A new debenzylation of aromatic benzyl ethers by silica-supported sodium hydrogen sulfate is described. The process proceeds selectively and efficiently in good to excellent yields without affecting sensitive functional groups such as nitro, COOMe, aldehyde, ketone, and tosyl.
- Zhou, Linna,Wang, Wenjing,Zuo, Li,Yao, Shanyan,Wang, Wei,Duan, Wenhu
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p. 4876 - 4878
(2008/09/21)
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- Ether aryl sulfonic acid esters with improved antimalarial/anticancer activities
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Our previous report showed that our current benchmark agent, 4-methoxyphenyl p-toluenesulibnate, is a selective antimalarial/anticancer agent. A series of related sulfones and sulfonic acid esters is now examined. 4-Allyloxyphenyl p-toluenesulfonate is a superior antimalarial/anticancer agent. 4-Methoxyphenyl 4-nitrobenzenesulfonate is a superior antimalarial agent, but shows poorer inhibition of human skin cancer cells. CSIRO 2006.
- Betts, Lynn M.,Tam, Nga Chiu,Kabir, S. M. Humayun,Langler, Richard F.,Crandall, Ian
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p. 277 - 282
(2008/02/08)
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- NOVEL COMPOUNDS AND THEIR USE IN MEDICINE, PROCESS FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM
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The present invention relates to novel compounds of formula (I) and their pharmaceutically acceptable salts thereof, pharmaceutical compositions containing them. The present invention also relates to a process for the preparation of the above said novel compounds.
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Page/Page column 73-74
(2010/02/11)
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- Development of a catalytic electron transfer system mediated by transition metal ate complexes: Applicability and tunability of electron-releasing potential for organic transformations
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We have developed a catalytic electron transfer (ET) system composed of a transition metal ate complex (Me3M(II)Li; M = Co(II), Mn(II), Fe(II)) and magnesium. This system (catalytic Me3M(II)Li/Mg) turned out to be effective for various ET reactions, such as the desulfonylation of N-phenylsulfonyl amides, and others (the chemoselective cleavage of O-allyl groups, the reduction of nitro groups, the partial reduction of diketones, and the reductive coupling of diphenyliodonium salt). The ET ability of this system can be tuned by changing the ligands of the ate complexes. This tunability was experimentally and electrochemically demonstrated: alkoxy-ligated and dianion-type ET ate complexes showed attenuated and enhanced reducing abilities, respectively. The modification of the ET abilities was evaluated by means of electrochemical measurements and chemical reactions. These results provide a basis for the design of various tailor-made ET ate complexes.
- Uchiyama, Masanobu,Matsumoto, Yotaro,Nakamura, Shinji,Ohwada, Tomohiko,Kobayashi, Nagao,Yamashita, Natsuno,Matsumiya, Atsushi,Sakamoto, Takao
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p. 8755 - 8759
(2007/10/03)
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- Selected sulfonyl compounds as anticancer/antimalarial agents
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The synthesis and biological testing of a series of sulfonyl phenols and sulfonyl aryl methyl ethers has revealed that p-methoxyphenyl p-toluenesulfonate is a very selective and effective antimalarial agent which shows pronounced activity against human skin cancer cells. Application of a counter-attack strategy permits the direct preparation of the requisite tosylate ether from the bis(tosylate) of dihydroquinone.
- Langler, Richard F.,Paddock, Robert L.,Thompson, David B.,Crandall, Ian,Ciach, Michelle,Kain, Kevin C.
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p. 1127 - 1133
(2007/10/03)
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- Simple, efficient, and selective deprotection of phenolic methoxymethyl ethers using silica-supported sodium hydrogen sulfate as a heterogeneous catalyst
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A simple and efficient method has been developed for chemoselective deprotection of phenolic methoxymethyl (MOM) ethers using silica-supported sodium hydrogen sulfate as a heterogeneous catalyst. The conversions occur at room temperature, and the yields of the deprotected phenols are excellent. The method is suitable for deprotection of phenolic MOM ethers of multifunctional bioactive natural products.
- Ramesh,Ravindranath,Das, Biswanath
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p. 7101 - 7103
(2007/10/03)
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- Efficient, selective deprotection of aromatic acetates catalyzed by Amberlyst-15 or iodine
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Aromatic acetates were selectively deprotected in the presence of aliphatic acetates to the corresponding phenols in excellent yields using Amberlyst-15 or iodine as catalysts in methanol at room temperature. The first catalyst can be recovered.
- Das, Biswanath,Banerjee, Joydeep,Ramu,Pal, Rammohan,Ravindranath,Ramesh
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p. 5465 - 5468
(2007/10/03)
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- Synthesis of Benzofurans from Oxygenated Phenoxyamines
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O-Aryloximes having various oxygenated substitution patterns have been converted to benzofurans, with implications toward natural product synthesis, through an extension of the Fischer indole type of synthesis.The effect of the substituent pattern in the benzene ring and the nature of the carbonyl derived portion of the oxime on benzofuranization were explored.
- Castellino, Angelo J.,Rapoport, Henry
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p. 4399 - 4404
(2007/10/02)
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