- Saccharin sulfonic acid catalyzed N-Boc protection of amines and formation of tertbutyl ethers from alcohols
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Saccharin sulfonic acid (SaSA), as a stable reagent is easily prepared by the reaction of saccharin with neat chlorosulfonic acid at room temperature. This compound is able to catalyze conversion of amines to their corresponding N-Boc protected amines with (Boc)2O. Alcohols were also converted to their corresponding tert-butyl ethers. All reactions took place under mild conditions giving the desired products in good to high yields.
- Shirini,Zolfigol,AbediniM.
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experimental part
p. 603 - 607
(2010/10/21)
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- Photochemical Transformations. 30. Photosolvolysis of Benzyl Chlorides in tert-Butyl Alcohol. 2. Nature of Excited States
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The photosolvolysis of a number of benzyl chlorides in tert-butyl alcohol, both as a result of direct irradiation and ketone triplet sensitization, has been studied.A variety of sensitization and quenching techniques have been used.The results obtained are rationalized by the assumption that there are two triplet states of the benzyl chlorides accessible in these experiments - one a short-lived upper state, which leads to solvolysis product, and another a long-lived (lower energy) state, which reverts to ground-state reactant.Consistent with this idea, m-methoxybenzyl chloride is shown to quench the photoreactions of benzopenone with benzhydrol without the formation of a significant amount of reactive species.The effects of wavelength on the reactions of p-acetobenzyl chloride are mesured and discussed in terms of the two-triplet concept.
- Cristol, Stanley J.,Bindel, Thomas H.
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p. 7287 - 7293
(2007/10/02)
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- Photochemical Transformations. 26. Sensitized and Unsensitized Photoreactions of Some Benzyl Chlorides in tert-Butyl Alcohol
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Benzyl chloride and a variety of meta- and para-substituted derivatives have been irradiated in tert-butylalcohol at 254 nm or in acetone-tert-butyl alcohol mixtures at 300 nm.Quantum and chemical yields of photosolvolysis products (benzyl tert-butyl ether and/or benzyl alcohol), photohomolysis products (bibenzyl and 4-phenyl-2-methyl-2-butanol), and corresponding products from substituted benzylchlorides have been measured as functions of substrate concentration and medium composition.Sensitized reactions favor bond heterolysis, but direct irradiations favor homolysis, although reactions are not clean in either case.There is no correlation between quantum yields for photosolvolysis and Hammett ? or Brown ?+ constants, and no salt effects of added lithium perchlorate were observed, in either direct or sensitized reactions.
- Cristol, Stanley J.,Bindel, Thomas H.
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p. 951 - 957
(2007/10/02)
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