Arylsulfonyl Group Research Articles

Effect of protection of amino group on direction of reaction of 2-aminoindole with ?,?-unsaturated ketones

The electron-acceptor properties of arylsulfonyl and carbobenzoxy groups decrease the probability of primary electrophilic attack at the nitrogen atom. They also determine primary attack at the 3-C atom of the indole ring. Michael addition products, 3,4-dihydro-α-carbolines, and α-carbolines themselves are obtained, depending on the reaction conditions. The reaction with α,β-unsaturated ketones proceeds under milder conditions in the case of 2-benzyloxycarbonylaminoindole.

6-Hydroxyindole derivatives from benzoquinonimines

The reaction of N-arylsulfonyl-2,6-dichloro-1,4-benzoquinonimines with 3-alkylamino-erotonates proceeds with displacement of the arylsulfonyl group and formation of a substituted 6-hydroxyindole.

Inhibition by 6-O-tosyl galactosides of beta-galactoside phosphorylation and transport by the lactose phosphotransferase system of Staphylococcus aureus.

The effect of various galactose derivatives, substituted at C-6, on the phosphoenolpyruvate:beta-galactoside phosphotransferase system of Staphylococcus aureus was studied. Cells were grown by an improved procedure, which resulted in a 5- to 10-fold increase in cell yield. The four protein components of the system were separated. A membrane fraction containing negligible levels of the soluble components was prepared by alternate cycles of sonic treatment and differential centrifugation. The in vitro system reconstituted from these fractions was used to test the ability of the galactose derivatives to inhibit the phosphorylation of lactose analogs, under conditions where the membrane-bound component, Enzyme IIlac, was rate limiting. Derivaites in which the hydroxyl group of C-6 was missing, or replaced by a fluoro, O-methyl, or carboxyl group had no affinity for Enzyme IIlac, as judged by their inability to inhibit phosphorylation. Surprisingly, derivatives containing arylsulfonyl groups at C-6 were potent inhibitors; the O-tosyl compound has an apparent affinity five times that of galactose. The arylsulfonyl substitution in an absolute requirement; neither O-benzyl or O-methanesulfonyl derivatives were inhibitory. The specificity of the inhibition by tosyl derivatives parallels that of unsubstituted substrates; tosyl galactosides of the beta configuration were inhibitory, but those of the alpha configuration were not. The tosyl derivatives also strongly inhibited the uptake of lactose analogs into whole cells; the requirement for the arylsulfonyl moiety was again observed. The chemical analogy between the tosyl galactosides and possible intermediates in the transport-phosphorylation step catalyzed by Enzyme IIlac provides a possible explanation for the unexpected properties of these derivatives.

The displacement of sulfonate groups by azide in cyclitols. Fully substituted 4-sulfonates of d-pinitol and 2-sulfonates of 1 l-1- O-methyl- allo-inositol

A series of p-toluenesulfonic and p-bromobenzenesulfonic esters was prepared from 1 d-1,2:5,6-di- O-isopropylidene-3- O-methyl- chiro-inositol (“diisopropylidenepinitol”, 1). In these compounds, the arylsulfonyl group was at position 4(3), and the substituents at positions 1,2,5, and 6 were isopropylidene, acetyl, methyl, and cyclic carbonate, respectively. Inversion of configuration at C-4 in 1 gave 1 d-1,2:5,6-di- O-isopropylidene-4- O-methyl- allo-inositol, from which a corresponding series of allo-inositol sulfonates was prepared. Rates of displacement of the sulfonate groups by azide ion ( N,N-dimethylformamide, 110°) were measured in both series, and the azido products were isolated and characterized. All of the azides except the penta- O-methyl- chiro derivative were convertible to one of two inosamine pentaacetates, which were shown to be 1 l-2-amino-2-deoxy-1- O-methyl- allo-inositol pentaacetate and 1 d-3-amino-3-deoxy-4- O-methyl- chiro-inositol pentaacetate, respectively.

The reaction of 2-arylsulfonyloxytropones and active methylene compounds: The formation of 8-hydroxy-2H-cyclohepta[b]furan-2-one and 2-amino-8H-cyclohepta[b]furan-8-one derivatives

Reaction of 2-arylsulfonyloxytropones (IV) and active methylene compounds, diethyl malonate, ethyl acetoacetate, ethyl cyanoacetate, malononitrile or cyanoacetamide, in the presence of NaOEt give 8-hydroxy-2H-cyclohepta[b]furan-2-one derivatives (V) and/or 2-amino-8H-cyclohepta[b]furan-8-one derivatives (VII), in addition to azulene derivatives (1) or 2H-cyclohepta(b]furan-2-one derivatives (II), known to be obtained by the reaction of 2-chlorotropones or 2-methoxytropones with active methylene compounds. Relative yields of products are influenced markedly by conditions, e.g. base type or molar ratios. The formation of V and VII is characteristic of 2-arylsulfonyloxytropones, not being observed with 2-chlorotropones or 2-methoxytropones. A reaction course involving elimination of the arylsulfonyl group as arenesulfinate ion is presented.