2346-07-8Relevant articles and documents
Visible-Light-Induced Passerini Multicomponent Polymerization
Tuten, Bryan T.,De Keer, Lies,Wiedbrauk, Sandra,Van Steenberge, Paul H. M.,D'hooge, Dagmar R.,Barner-Kowollik, Christopher
supporting information, p. 5672 - 5676 (2019/03/26)
Herein, we introduce an additive-free visible-light-induced Passerini multicomponent polymerization (MCP) for the generation of high molar mass chains. In place of classical aldehydes (or ketones), highly reactive, in situ photogenerated thioaldehydes are exploited along with isocyanides and carboxylic acids. Prone to side reactions, the thioaldehyde moieties create a complex reaction environment which can be tamed by optimizing the synthetic conditions utilizing stochastic reaction path analysis, highlighting the potential of semi-batch procedures. Once the complex MCP environment is understood, step-growth polymers can be synthesized under mild reaction conditions which—after a Mumm rearrangement—result in the incorporation of thioester moieties directly into the polymer backbone, leading to soft matter materials that can be degraded by straightforward aminolysis or chain expanded by thiirane insertion.
BIARYL-PROPIONIC ACID DERIVATIVES AND THEIR USE AS PHARMACEUTICALS
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Page/Page column 89, (2014/10/15)
The present invention relates to compounds of the formula (I), wherein X, R, R1, R2, D, E1, E2, E3, E4, G1, G2, G3 and G4 have the meanings indicated in the claims, which are valuable pharmaceutical active compounds. They are inhibitors of the protease ca
BIARYL-PROPIONIC ACID DERIVATIVES AND THEIR USE AS PHARMACEUTICALS
-
Page/Page column 97, (2014/10/15)
The present invention relates to compounds of the formula (I), wherein X, R, R1, R2, D, E1, E2, E3, E4, G1, G2, G3 and G4 have the meanings indicated in the claims, which are valuable pharmaceutical active compounds. They are inhibitors of the protease ca
Profiling sulfonate ester stability: Identification of complementary protecting groups for sulfonates
Miller, Stephen C.
supporting information; experimental part, p. 4632 - 4635 (2010/09/17)
(Figure presented) Sulfonation is prized for its ability to impart water-solubility to hydrophobic molecules such as dyes. This modification is usually performed as a final step, since sulfonated molecules are poorly soluble in most organic solvents, which complicates their synthesis and purification. This work compares the intrinsic lability of different sulfonate esters, identifying new sulfonate protecting groups and mild, selective cleavage conditions.
Application of alkoxy-λ6-sulfanenitriles as strong alkylating reagents
Hao, Wei,Fujii, Takayoshi,Dong, Tiaoling,Wakai, Youko,Yoshimura, Toshiaki
, p. 193 - 198 (2007/10/03)
Alkoxy-λ6-sulfanenitriles were found to be versatile alkylating reagents toward various nucleophiles bearing at least one proton such as methanol, phenol, thiophenols, carboxylic acids, ptoluenesulfonic acid, hydrochloric acid, and primary and secondary amines. Reactivity of the alkoxy group of the λ6-sulfanenitriles showed an opposite trend to the usual SN2 character, i.e. Me (la), Pr (1b), and Bu (1d) ? i-Pr (1c). In the presence of p-TsOH, alkyl tosylates were predominantly formed instead of the alkylation products of nucleophiles. In addition, even a sterically hindered substrate, neopentyloxy-λ6-sulfanenitrile, was found to undergo an SN2 reaction toward thiophenol without any rearrangement product to give neopentyl phenyl sulfide in good yield.
Nickel(0)-catalyzed cross-coupling of alkyl arenesulfonates with aryl Grignard reagents
Cho, Chul-Hee,Yun, Hee-Sung,Park, Kwangyong
, p. 3017 - 3025 (2007/10/03)
The nickel-catalyzed cross-coupling reactions of neopentyl arenesulfonates with arylmagnesium bromides, involving nucleophilic aromatic substitution of alkyloxysulfonyl groups by aryl nucleophiles, take place in high yields. Optimal efficiencies are obtained by adding 3 + 2 equiv of the Grignard reagent to a mixture of dppfNiCl2 and the sulfonate in refluxing THF. Neopentyl arenesulfonates are useful sources of the electrophilic aryl groups in these transition metal-catalyzed cross-coupling reactions. Aryl sulfonates are inappropriate due to their ambident reactivity under the reaction conditions. This new cross-coupling reaction can be used for the creative elimination of alkyloxysulfonyl groups from aromatic compounds and for the preparation of unsymmetric terphenyls and oligophenyls.
Octaarylethynyl and octaarylbutadiynyl phthalocyanines
Leznoff,Suchozak
, p. 878 - 887 (2007/10/03)
4,5-Diphenylethynylphthalonitrile, 4,5-di(p-tert-butylphenylethynyl)phthalonitrile, 4,5-di(p-neopentoxyphenylethynyl)phthalonitrile, and 4,5-di(p-neopentoxyphenyl-1,3-butadiynyl)phthalonitrile were prepared via 4,5-diiodophthalonitrile and the appropriate
1,4-Diazabicyclo[2.2.2]octane (DABCO)- an efficient reagent in the synthesis of alkyl tosylates or sulfenates
Hartung, Jens,Huenig, Siegfried,Kneuer, Rainer,Schwarz, Michaela,Wenner, Hermann
, p. 1433 - 1438 (2007/10/03)
The bieyclic tertiary amine 1,4-diazabicyclo[2.2.2]octane (DABCO) is 8 promising substitute not only for the widely used but hazardous and hygroscopic base pyridine in the syntheses of alkyl tosylates 3 but also for triethylamine in the preparation of alk
Solvent Effects on Solvolytic Reactivity. A Diagnostic Test for Neighboring-Group Assistance by ? Conjugation in Solvolysis Reactions
Roberts, Donald D.
, p. 2521 - 2526 (2007/10/02)
The solvolysis rates of 13 arenesulfonates have been determined in mixtures of ethanol and water (the E-series solvents) and acetic acid and formic acid (the A-series solvents).The substrates studied include the following: neophyl (1), 2-adamantyl (2), neopentyl (3), and cyclooctyl (4) tosylates; cyclopropylcarbinyl pemsylate (5a) and tosylate (5b); exo-2-norbornyl tosylate (6); cyclobutylcarbinyl (7), cyclobutyl (8), and pinacolyl (9) brosylates; cyclopentyl (10), cyclohexyl (11), and 2-propyl (12) tosylates; and cyclopentylcarbinyl brosylate (13).Correlations of the rate data by eq 1 t(Y) = a + b log kt(neophyl-OTs)> showed that the various substrates responded differently to the examined solvent effects on the solvolytic reactivity.For compounds 2-4, linear correlations were obtained.For compounds 5-9, E-line, A-line dispersions were noted which diverged with increasing ionizing power; for compounds 10-12, parallel E-line, A-line dispersions were obtained; and for compound 13, an E-line, A-line dispersion was observed which converged with increasing ionizing power.Stastistical analyses of the rate data correlations confirmed the significance of the E or A classification of data.The results are interpreted in terms of differences in the involvement of solvent in the transition state for those solvolyses assisted by bridging from those assisted by C-C ? bond hyperconjugation.
Reduction of Sulfonic Acids and Related Organosulfur Compounds with Triphenylphosphine-Iodine System
Oae, Shigeru,Togo, Hideo
, p. 3802 - 3812 (2007/10/02)
Arenesulfonic acids, their sodium salts, and alkyl arenesulfonates can be reduced readily to the corresponding arenethiols quantitatively by treatment with a mixture of triphenylphosphine and a catalytic amount of iodine, while alkanesulfonic acids, sulfinic acids, disulfides, thiosulfonic S-esters, and sulfonates are also readily reduced to the corresponding thiols similarly.Upon treatment with a mixture of triphenylphosphine and excess iodine, however, these aliphatic sulfur compounds are converted eventually to the corresponding alkyl iodides.The relative reactivities of these sulfonyl derivatives in the reaction with the triphenylphosphine-iodine system are the following.Aromatic series: ArSO2Cl, ArSO2SAr' > ArSO2H > ArSO3R > ArSO3-HNBu3+ (or PyH+) > ArSO3H > ArSO2SO2Ar >> ArSO2CH2C(CH3)3, ArSO3Ar'.Aliphatic series: RSO2Cl, RSO2SR', RSO2-HNBu3+ > RSO3-HNBu3+ > RSSR, RSO2H > RSO3H > RSH > RSO3R'.In these reactions, the arenesulfonic acids bearing electron-donating substituents can be reduced more readily than those having electron-withdrawing substituents.
