Direct Introduction of a Dimesitylboryl Group Using Base‐Mediated Substitution of Aryl Halides with Silyldimesitylborane

The first dimesitylboryl substitution of aryl halides with a silylborane bearing a dimesitylboryl group in the presence of alkali‐metal alkoxides is described. The reactions of aryl bromides or iodides with Ph₂MeSi?BMes₂ and Na(OtBu) afforded the desired aryl dimesitylboranes in good to high yields and with high borylation/silylation ratios. Selective reaction of the sterically less‐hindered C?Br bond of dibromoarenes provided monoborylated products. This reaction was used to rapidly construct a D‐π‐A aryl dimesityl borane with a non‐symmetrical biphenyl spacer.     

Palladium‐Catalyzed Arylation of Olefins by Triarylphosphines via CP Bond Cleavage

C? H Arylation of olefins by triarylphosphines via C? P bond cleavage has been achieved with either Pd⁰ or Pd^II catalysts. A variety of olefins and triarylphosphines are tolerated, and we inferred that both Pd⁰ and Pd^II could function directly without pre‐oxidation or pre‐reduction.     

Exchange reactions of tetrathiophosphates with thiophosphoryl chloride

Exchange reactions of tetrathiophosphates with thiophosphoryl chloride were studied. The exchange of thiol groups between compounds with tetracoordinated phosphorus centers proceeds at 150–220°C and results in the formation of dialkyl trithiochlorophosphates and alkyl(aryl) dithiodichlorophosphates or their mixtures depending on the ratio of the reagents. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1815–1817, September, 1998.     

Solvent-free Efficient Synthesis of Symmetrical Isocyanurates by a Combination Catalyst: Sodium Saccharin and Tetrabutylammonium Iodide

Summary. Combination of sodium saccharin and tetrabutylammonium iodide as a novel anionic catalyst system promotes selectively the trimerization of isocyanates to give symmetrical isocyanurates under solvent-free conditions.Present Address: College of Chemistry, Isfahan University of Technology, Isfahan, 84154, Iran     

The Autoxidation of Triaryl Trithioarsenites, (ArS)3As: Evidence for Binding and Activation of Triplet Dioxygen by Arsenic(III)

Triaryl trithioarsenites, (ArS)₃As, are oxidized by air to As ₂ O ₃ and ArSSAr. In two cases the parent “thiol” (pyrid-2-thione and 1-hydroxypyrid-2-thione) is coproduced. The oxidation, in nonprotic solvents, is favored by electron-withdrawing groups at the para position of the phenyl group. The products obtained in nonprotic solvents were rationalized by assuming that the binding of the triplet dioxygen to arsenic(III) gives a triplet diradical, (ArS) ₃ A?─O─?, or an arsenadioxirane, (ArS) ₃ As(O ₂ ), intermediate, which decomposes after nucleophilic attack by another (ArS) ₃ As molecule. In protic solvents a zwitterion, (ArS) ₃ As⁺─O─O^?, and in the presence of moisture a hydroperoxy arsenic(V) compound, (ArS)₃As(OH)─O─OH, may be intermediates in the air oxidation of some aromatic trithioarsenites. These data tend to indicate that arsenic(III) bound to suitable groups can directly bind dioxygen, a property which may have implications in chemotherapy and carcinogenesis.     

反式-5,1O,15-三芳基-5,1O,15-三羟基-1-氢-三苯并[a,f,k]三茚的合成与从头算结构分析

合成了两个具有三个羟基的新型主体分子反式－5,10,15－三芳烃－5,10,15－三羟基－1－氢－三苯并[a,f,k]三茚（芳基分别为苯基和－萘基）,并通过从头算对其及其异构体的结构进行了分析,结果发现当芳基为苯基时,其顺式异构体分子印环中所有原子不完全处于共平面,而其反式异构体和1－萘基的顺反异构体均处于共平面。     

Sequential Aldol/Michael Addition Reaction in Ionic Liquid Catalyzed by Morpholine: A Convenient Synthesis of 1,3,5‐Triaryl‐1,5‐pentanedione

A series of 1,3,5‐triaryl‐1,5‐pentanediones was obtained via a sequential aldol condensation and Michael addition reaction in ionic liquid catalyzed by morpholine, as a one‐pot reaction. The significance of our findings relates to reducing the use of organic solvents, potentially toxic and hazardous materials, as well as its simplicity, good yields, mild conditions, and lower costs.     

I2‐Catalyzed Divergent Regioselective Addition of Methoxybenzenes with Ethenylbenzenes under Microwave Irradiation

A highly efficient synthesis of 1,2,2‐triarylethanones has been developed from simple and commercially available electron‐rich arenes and styrenes (ethenylbenzenes).     

Preparation and characterization of polyimides containing triaryl imidazole side groups

A novel triaryl imidazole‐containing diamine, 3,5‐diamino‐N‐(4‐(4,5‐diphenyl‐1H‐imidazol)phenyl)benzamide, was successfully synthesized via the condensation of 4‐(4,5‐diphenyl‐1H‐imidazol)benzenamine and 3,5‐dinitrobenzoyl chloride, followed by reduction of the dinitro compound. A series of new aromatic polyimides with pendent triaryl imidazole moieties were prepared from the reaction of this diamine with various tetracarboxylic dianhydrides by a conventional two‐step polymerization process via thermal and chemical imidizations. The polyimides were obtained in quantitative yields with inherent viscosities of 0.21–0.44 dL/g. All the polymers are readily soluble in polar organic solvents. Flexible and strong films of polyimides were obtained by solution casting. The glass transition temperature of these polymers was in the range of 261–264°C. They were fairly stable up to a temperature around 300°C and lost 10% weight at 408°C under nitrogen. The ultraviolet–visible absorption spectra showed that all of the polymers had absorption maxima around 320 nm with a fluorescence emission maxima around 388–407 nm in N‐methyl‐2‐pyrrolidinone solution. Cyclic voltammograms of the polyimides revealed an oxidation wave with a peak around 1.7 V. Copyright © 2016 John Wiley & Sons, Ltd.