Tunable Photocatalytic Oxysulfonylation and Chlorosulfonylation of α-CF3 Alkenes with Sulfonyl Chlorides

Author(s):  
Peng-Ju Xia ◽  
Fu Liu ◽  
Shu-Hui Li ◽  
Jun-An Xiao

Tunable photoredox-catalyzed chlorosulfonylation and oxysulfonylation of α-trifluoromethylstyrenes with sulfonyl chloride were facilely achieved by simply manipulating photocatalyst and solvent. This strategy makes full use of the structural features of sulfonyl...

2016 ◽  
Vol 22 (6) ◽  
Author(s):  
Huiping Wei ◽  
Gaigai Wang ◽  
Binbin Li ◽  
Jianjun Huang ◽  
Haiyan Li ◽  
...  

Abstract2-Aminopyridine-3-sulfonyl chlorides undergo a reaction with tertiary amines in the presence of air to produce sulfonylethenamines. The 2-aminopyridine-3-sulfonyl chloride apparently plays a dual role in the process promoting the aerobic oxidation of the amine and electrophilically trapping the resulting enamine.


Synthesis ◽  
2020 ◽  
Vol 52 (15) ◽  
pp. 2259-2266
Author(s):  
Mikhail Krasavin ◽  
Dmitry Dar’in ◽  
Grigory Kantin ◽  
Olga Bakulina

A convenient one-pot approach to the preparation of α-diazo-β-ketosulfones from sulfonyl chlorides is described. It involves the conversion of the sulfonyl chloride to sodium sulfinate, alkylation of the latter with α-haloketones followed by diazo transfer using the ‘sulfonyl-azide-free’ (‘SAFE’) protocol in aqueous medium. The simple and expedient method relies on readily available starting materials and provides facile access to a wide variety of valuable diazo reagents for organic synthesis.


1978 ◽  
Vol 31 (12) ◽  
pp. 2669 ◽  
Author(s):  
RJ Cremlyn ◽  
RW Pannell

Phenoxyacetamide (2) by treatment with chlorosulfonic acid gave the 4- sulfonyl chloride (3); this was characterized by preparation of the sulfonamide (4) and the sulfonohydrazide (5). The latter compound has been converted into five hydrazones (6) by condensation with the appropriate carbonyl compounds; with acetylacetone cyclization occurred to form the 3,5-dimethylpyrazole (7). 2,4-Dichloro- and 4-chloro-2- methyl-phenoxyacetamides were chlorosulfonated to the corresponding 6- sulfonyl chlorides (8) and (10), and these were characterized as the sulfonohydrazides (9) and (11). In contrast, attempts to chlorosulfonate 2,4-dichloro- and 4-chloro-2-methyl-phenoxyacetic acids were unsuccessful, and the reasons for this failure are briefly discussed.


2010 ◽  
Vol 7 (1) ◽  
pp. 641-653
Author(s):  
Baghdad Science Journal

Eighteen new cyclic imides (maleimides) conncted to benzothiazole moiety through sulfonamide group were synthesized via multistep synthesis.The first step involved preparation of two maleamic acids N-phenylmaleamic acid and N-benzylmaleamic acid via reaction of maleic anhydride with aniline or benzyl amine.Dehydration of the prepared amic acids by treatment with acetic anhydride and anhydrous sodium acetate in the second step afforded N-phenylmaleimide and N- benzyl maleimide which in turn were treated with chlorosulfonic acid in the third step to afford 4-(N-maleimidyl) phenyl sulfonyl chloride and 4-(N-maleimidyl) benzyl sulfonyl chloride respectively.In the Fourth step of this work each one of the two prepared maleimidyl sulfonyl chlorides was introduced in reaction with nine substituted-2-amino benzothiazole compounds producing nine N-(4-(N-substituted benzothiazole -2-yl) sulfonamido phenyl) maleimides and nine N-(4-(N-substituted benzothiazole-2-yl)snlfonamido benzyl) maleimides.More over another new six sulfonamide phenyl and benzyl maleimides substituted with other heterocycles (pyridine and phenazone )were prepared via reaction of 4-(N-maleimidyl) phenyl and benzyl sulfonyl chlorides with heterocyclic amines including (2-amino pyridine,4-amino-pyridine,4-aminophenazone). Microbiological activity of the prepared compounds against two typs of bacteria(staphylococcus aureus and klebsiella pneumonia) and (candida albicans) fungi were evaluated and the results showed that these compounds have good antibacterial and good antifungal activities.


Author(s):  
O.C. de Hodgins ◽  
K. R. Lawless ◽  
R. Anderson

Commercial polyimide films have shown to be homogeneous on a scale of 5 to 200 nm. The observation of Skybond (SKB) 705 and PI5878 was carried out by using a Philips 400, 120 KeV STEM. The objective was to elucidate the structural features of the polymeric samples. The specimens were spun and cured at stepped temperatures in an inert atmosphere and cooled slowly for eight hours. TEM micrographs showed heterogeneities (or nodular structures) generally on a scale of 100 nm for PI5878 and approximately 40 nm for SKB 705, present in large volume fractions of both specimens. See Figures 1 and 2. It is possible that the nodulus observed may be associated with surface effects and the structure of the polymers be regarded as random amorphous arrays. Diffraction patterns of the matrix and the nodular areas showed different amorphous ring patterns in both materials. The specimens were viewed in both bright and dark fields using a high resolution electron microscope which provided magnifications of 100,000X or more on the photographic plates if desired.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
U. Aebi ◽  
P. Rew ◽  
T.-T. Sun

Various types of intermediate-sized (10-nm) filaments have been found and described in many different cell types during the past few years. Despite the differences in the chemical composition among the different types of filaments, they all yield common structural features: they are usually up to several microns long and have a diameter of 7 to 10 nm; there is evidence that they are made of several 2 to 3.5 nm wide protofilaments which are helically wound around each other; the secondary structure of the polypeptides constituting the filaments is rich in ∞-helix. However a detailed description of their structural organization is lacking to date.


Author(s):  
R.M. Glaeser ◽  
S.B. Hayward

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.


Author(s):  
Godfrey C. Hoskins ◽  
Betty B. Hoskins

Metaphase chromosomes from human and mouse cells in vitro are isolated by micrurgy, fixed, and placed on grids for electron microscopy. Interpretations of electron micrographs by current methods indicate the following structural features.Chromosomal spindle fibrils about 200Å thick form fascicles about 600Å thick, wrapped by dense spiraling fibrils (DSF) less than 100Å thick as they near the kinomere. Such a fascicle joins the future daughter kinomere of each metaphase chromatid with those of adjacent non-homologous chromatids to either side. Thus, four fascicles (SF, 1-4) attach to each metaphase kinomere (K). It is thought that fascicles extend from the kinomere poleward, fray out to let chromosomal fibrils act as traction fibrils against polar fibrils, then regroup to join the adjacent kinomere.


Author(s):  
P. S. Kotval ◽  
C. J. Dewit

The structure of Ta2O5 has been described in the literature in several different crystallographic forms with varying unit cell lattice parameters. Earlier studies on films of Ta2O5 produced by anodization of tantalum have revealed structural features which are not consistent with the parameters of “bulk” Ta2O5 crystalsFilms of Ta2O5 were prepared by anodizing a well-polished surface of pure tantalum sheet. The anodic films were floated off in distilled water, collected on grids, dried and directly examined in the electron microscope. In all cases the films were found to exhibit diffraction patterns representative of an amorphous structure. Using beam heating in the electron microscope, recrystallization of the amorphous films can be accomplished as shown in Fig. 1. As suggested by earlier work, the recrystallized regions exhibit diffraction patterns which consist of hexagonal arrays of main spots together with subsidiary rows of super lattice spots which develop as recrystallization progresses (Figs. 2a and b).


Sign in / Sign up

Export Citation Format

Share Document