- (1-Nosyl-5-nitroindol-3-yl)methyl ester: A novel protective group for carboxylic acids
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(Chemical Equation Presented) The usefulness of (1-nosyl-5-nitroindol-3-yl) methyl esters as a novel protective group for carboxylic acid is fully demonstrated. The novel protective group is stable under a broad range of conditions and can easily be deprotected under the mild conditions used for removal of the nosyl (Ns) group. It is orthogonal to the existing protective groups for carboxylic acids such as t-butyl and allyl esters.
- Nishimura, Takuya,Yamada, Kouhei,Takebe, Tohru,Yokoshima, Satoshi,Fukuyama, Tohru
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scheme or table
p. 2601 - 2604
(2009/05/26)
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- Methodology for the efficient synthesis of 3,4-differentially substituted indoles. Fluoride ion-induced elimination-addition reaction of 1-triisopropylsilylgramine methiodides
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1-Triisopropylsilylgramine methiodide reacted smoothly with a variety of nucleophiles in the presence of tetrabutylammonium fluoride to give 3-substituted indoles. The 3,4-disubstituted indoles were efficiently synthesized by sequential use of 4-selective lithiation of 1-triisopropylsilylgramine and this new substitution reaction.
- Iwao, Masatomo,Motoi, Osamu
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p. 5929 - 5932
(2007/10/02)
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- 1-and 2-azafulvenes
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Flash pyrolysis of dialkylaminopyrroles and thermolysis of 2-pyrrylmethyl phenyl sulfoxide at 65°C in solution gave azafulvenes which were trapped with a variety of nucleophiles.
- Barcock,Moorcroft,Storr,Young,Fuller
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p. 1187 - 1190
(2007/10/02)
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- Cobalt-mediated Reactions in Synthesis. The Degradation of Carboxylic Acids to Functionalised Noralkanes via Acylcobalt Salophen Intermediates
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Arylmethyl- and allyl-carbonylcobalt salophen complexes, e.g. (7), (8), (9), and (22), readily undergo carbon-to-cobalt-bond homolysis and in situ decarbonylation, producing new alkyl radical centres which can be intercepted with oxygen-, nitrogen-, halogen-, sulphur-, and selenium-containing trapping agents leading to functionalised noralkanes.The sequence constitutes a useful, and in some cases more flexible, variant of the classical Hunsdiecker reaction, and amounts to a cobalt equivalent of the Barton radical decarboxylation reaction of carboxylic acids via their corresponding thiohydroxamic esters.In a similar manner, irradiation of the oxy-substituted acylcobalt salen reagents (25) and (26) in the presence of tetramethylpiperidine oxide produces the products (14) and (27), respectively, resulting from homolysis-decarboxylation and alkyl-radical trapping.In the absence of radical-trapping agents, irradiation of (7c) produces (18), and irradiation of (29) leads to the but-2-enolide (32).
- Patel, Vinod F.,Pattenden, Gerald,Thompson, David M.
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p. 2729 - 2734
(2007/10/02)
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- FREE RADICAL REACTIONS INITIATED BY ORGANOCOBALT COMPLEXES. A NEW METHOD FOR THE DEGRADATION OF CARBOXYLIC ACIDS TO FUNCTIONALISED NOR-ALKANES VIA ACYLCOBALT SALOPHEN INTERMEDIATES.
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Arylmethyl- and allyl-acylcobalt salophens, undergo facile C-Co bond homolysis and in situ decarbonylation, producing new (alkyl) radical centres which can be intercepted with oxygen, nitrogen, halogen, sulphur and selenium containing radical trapping agents, leading to functionalised nor-alkanes (Scheme).
- Patel, Vinod F.,Pattenden, Gerald
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p. 707 - 710
(2007/10/02)
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