磺酰氯与不饱和化合物的反应

磺酰氯是一类重要的有机合成中间体,广泛应用于有机和药物合成中。磺酰氯可以作为烯砜、磺酰基、次磺酰基、芳基、氟代烷基等的来源应用于多种有机合成反应中。本文综述了磺酰氯与烯烃、炔烃、(杂)芳香环、亚胺、卤代醛酮等不饱和化合物的反应,主要包括[2+2]环合反应、氯磺酰化、磺酰化、次磺酰化、芳基化和氟代烷基化等反应,并讨论和预测了磺酰氯与不饱和化合物反应今后的发展方向。     

Synergism in molybdenum iron sulphur cluster compounds. Synthetic,structural, magnetic,cyclic voltammetric evidence and the reaction of dicubane clusters containing [MoFe3S4] unit

Summary Dicubane cluster compounds (Et₄N)₄[Mo₂Fe₇S₈(SR)₁₂] (2A) (R=Ph,a;o-tolyl,b;m-tolyl,c;p-tolyl,d) were made by reaction of (Et₄N)₂[Fe₄(SR)₁₀] (1) with (Et₄N)₂MoS₄ in MeCN at room temperature. The structure,¹Hn.m.r.,⁵⁷Fe Mössbauer spectrum, magnetic susceptibility and cyclic voltammogram are described. (Et₄N)₃[Mo₂Fe₆S₈Cl₆(SR)₃] (3) (R=Ph,a;m-tolyl,b) was obtained from the reaction of (2Aa) or (2Ac) with acetyl chloride in MeCN. This is the first time that compound of structural type (2) is transformed into that of structural type (3) by chemical conversion. Compound (2Aa) crystallizes in the triclinic space group P with Z=1 and unit cell dimensionsa=12.775(4),b=13.076(3), andc=20.576(4) Å; the structure was refined to R=7.7% using 4031 unique data with I>3(I_o). Compound (2Ac) 2THF crystallizes in the monoclinic space group P2₁/n with Z=2 and unit cell dimensionsa=18.022(2),b=18.375(2) andc=22.254(3) Å; the structure was refined to R=6.4% using 5173 unique data with I>3(I_o). Compound (3b) crystallizes in the hexagonal space groupP6₃/m with Z=2 and unit cell dimensionsa=b=16.827(3) andc=15.951(16) Å; the structure was refined to R=4.9% using 1296 unique data with I>3(I_o). Its characteristics are discussed and compared with those of known compounds. The ratios of core volumes S₄/M₄ are within the 2.34–2.40 range for core oxidation level [MoFe₃S₄]³⁺ indicating that distortion of the cubane core is a general phenomenon. Different thiolato ligands induce significant changes of structural parameters only at the Fe(SR)₆ region for compound (2A) while terminal chlorides induce changes over the whole molecule of (3b) with the latter structure more comparable to [Mo₂Fe₆S₈(SPh)₉]^5– (3f) with [MoFe₃S₄]²⁺ core than to [Mo₂Fe₆S₈(SPh)₉]^3– (3d). The isotropic shifts of (2A) originate mainly from -contact interaction. Both¹H n.m.r. spectra and magnetic susceptibility measurements indicate practically no magnetic interaction among the three magnetic centres,i.e. a Fe(SR)₆ bridge and two [MoFe₃S₄(SR)₃] units. CV studies showed that the reduction of cubane unit having aromatic thiolates is easier than that having aliphatic thiolates as the aliphatic group is electron-donating. In addition, the very similar differences of E_p,c for first and second cubane units in compounds (2A) and in (3d) and (3e) imply that the effect of the first reduced unit [MoFe₃S₄]²⁺ upon the second unit [MoFe₃S₄]³⁺ is very similar in the two types of dicubane cluster compounds. Synergism in Mo–Fe–S cluster compounds is thus proposed to play an important role in their structural correlation with reactivities and must function in nitrogenase.     

Asymmetric aziridination of chalcones catalyzed by a novel backbone 1,8-bisoxazolinylanthracene (AnBOX)-copper complex

Highly enantioselective aziridination of chalcones catalyzed by a novel backbone 1,8-bisoxazolidinylanthracene (AnBOX) and CuOTf with up to >99% ee and the opposite enantioselectivity compared with the ligands of Evans are described.     

Bulk and shear rheology of a symmetric three‐arm star polystyrene

The bulk and shear rheological properties of a symmetric three‐arm star polystyrene were measured using a self‐built pressurizable dilatometer and a commercial rheometer, respectively. The bulk properties investigated include the pressure–volume–temperature behavior, the pressure‐dependent glass transition temperature (T_g), and the viscoelastic bulk modulus and Poisson's ratio. Comparison with data for a linear polystyrene indicates that the star behaves similarly but with slightly higher T_gs at elevated pressures and slightly higher limiting bulk moduli in glass and rubbery states. The Poisson's ratio shows a minimum at short times similar to what is observed for the linear chain. The horizontal shift factors above T_g obtained from reducing the bulk and shear viscoelastic responses are found to have similar temperature dependence when plotted using T ? T_g scaling; in addition, the shift factors also exhibit a similar temperature dependence to linear polystyrene. The retardation spectra for the bulk and shear responses are compared and show that the long time molecular mechanisms available to the shear response are unavailable to the bulk. At short times, the two spectra have similar slopes, but the short‐time retardation spectrum for the shear response is significantly higher than that for the bulk, a finding that is, as yet, unexplained. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012     

Efficient synthesis of protected sulfonopeptides from N-protected 2-aminoalkyl xanthates and thioacetates

An efficient and convenient method was developed for the synthesis of protected sulfonopeptides via N-chlorosuccimide (NCS)/HCl oxidative chlorination of N-protected 2-aminoalkyl xanthates or thioacetates to the corresponding sulfonyl chlorides followed by aminolysis with amino esters. In the current method, sulfonopeptides containing 1- and 2-substituted taurines were prepared in satisfactory to good yields. It is a useful and efficient strategy for the synthesis of protected sulfonopeptides with functionalized side-chains.     

Diverse Reactions of Sulfonyl Chlorides and Cyclic Imines

Abstract

Although alkanesulfonyl chlorides react with linear imines to give rise to β-sultam derivatives, in this study, they were reacted with various cyclic imines, including 1-pyrroline, oxazoline, 5,6-dihydro-4H-oxazines and thiazines, 4,5-dihydro-3H-benzo[c]azepine, and 3,4-dihydroisoquinoline, to produce diverse products instead of β-sultam derivatives. The results indicate that alkanesulfonyl chlorides react with cyclic imines to generate N-alkanesulfonyl cyclic iminium ions, which are attacked by nucleophiles, such as water and chloride anion, in the reaction systems, affording addition products. The iminium intermediates cannot undergo a ring closure to form β-sultam derivatives. Arenesulfonyl chlorides showed similar behavior when they reacted with cyclic imines. The scope and limitation of the reaction between sulfonyl chlorides and imines were investigated.

GRAPHICAL ABSTRACT      

A Convenient Synthesis of Thiazolidin-2-ones from Thiazolidine-2-thiones: Antibiotic Activity and Revisiting the Mechanism

Abstract

Various substituted thiazolidin-2-ones were synthesized from the corresponding thiazolidine-2-thiones with bromoethanol in ethanol with sodium ethoxide as a base. The optimal reaction conditions and mechanism were reinvestigated in detail. The bioassay indicated that (S)-4-isobutyl and (S)-4-benzylthiazolidin-2-ones show certain inhibitive activities against Candida albicans and Escherichia coli.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT     

Fabrication of Cu-Doped CeO<Subscript>2</Subscript> Catalysts with Different Dimension Pore Structures for CO Catalytic Oxidation

Transition metal oxides (TMOs) applied as catalysts whose catalytic activities are directly affected by their pores size and pores distributions. Herein, two-dimensional Cu-doped CeO₂ (2D@Cu–CeO₂) and three-dimensional Cu-doped CeO₂ (3D@Cu–CeO₂) were prepared by adopting the mesoporous silica SBA-15 and KIT-6 as templates, respectively. Nanometer Cu-doped CeO₂ (nano@Cu–CeO₂) was synthesized by the method of precipitation. All catalysts were evaluated for the catalytic oxidation of CO, and the 3D@Cu–CeO₂ catalyst exhibited the highest catalytic activity (complete conversion temperature T₁₀₀?=?50?°C), which can be ascribed to the three-dimensional porous channel structure, larger specific surface area and abundant active surface oxygen species. In addition, complete conversion of CO had remained the same after 3D@Cu–CeO₂ was observed for 12 h, indicating it has the best catalytic stability for CO.     

Light-activated gating and permselectivity in interfacial architectures combining "caged" polymer brushes and mesoporous thin films

We demonstrate that "caged" macromolecular building blocks can endow mesoporous thin films with light responsiveness and lead to the creation of functional hybrid ensembles with phototriggered permselective properties.     

Unexpected stereomutation dependence on the chemical structure of helical vinyl glycopolymers

A small change in chemical structure causes a remarkable influence on the stereostructure stability and mutarotational rate of helical vinyl polymers bearing laterally attached p-terphenyl pendants with an achiral butoxy terminal and a chiral galactosyloxy terminal.