Organylthiochloroacetylenes: IV. Reaction with Thiourea

Alkylthiochloroacetylenes react with thiourea in acetone to form S-(alkylthioethynyl)isothiuronium chlorides and N-[1-(alkylthio)ethylidene]thioureas; phenylthiochloroacetylene reacts with thiourea to give 4-(phenylthio)-2-imino-1,3(3H)-thiazole hydrochloride.     

Phosphazenes: I. Reactions with electron-deficient alkenes

Triphenylphosphazenes reacted with methyl vinyl ketone, methyl acrylate, methyl methacrylate, and dimethyl maleate to give the corresponding substituted dihydropyrazoles.     

Electrodes surface-intercalated with powder catalysts: II. Microelectrodes surface-intercalated with powder catalysts

Microelectrode techniques were worked out for the study of electrocatalytic behaviors of powder catalysts. Ultra thin layer of fine catalyst powder was intercalated into the surface layer of soft conductive plastic sheet made from acetylene black and polytetrafluoroethylene (PTFE) binder. Microelectrodes of such construction have been successfully employed in the study of reversible and irreversible electrode reactions. Experimental results clearly indicated that microelectrode with ultra thin layer of surface-intercalated catalyst powder could serve as a powerful tool for the study of electrocatalytic behaviors of powder catalysts.     

ChemInform Abstract: Interactions of Hydrogen with CeO2.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.     

Organoboranes: XXXIII. Protonolysis of triethylborane with carboxylic acids

The hydrolysis of triethylborane with water proceeds very slowly at room temperature, unaffected by hydrochloric acid, but inhibited by sodium hydroxide. Acetic acid, however, removes the first ethyl group rapidly, followed by a slower removal of the second. The protonolysis of the third ethyl group requires elevated temperatures. The unusual reactivity of carboxylic acid toward protonolysis of triethylborane is attributed to the presence of both acidic and basic sites in close proximity. The effect of added reagents is also studied. Thus, bases, such as pyridine, inhibit the removal of the first ethyl group, whereas, hydroxylic solvents, water, and strong acids and bases hinder protonolysis of the second ethyl group.     

Hexamethylsilirane: II. Ring-opening reactions with some simple reagents

Ring-opening reactions formally of the type Me₂SiCMe₂CMe₂ ? X-H→ Me₂XSiCMe₂CMe₂H occur on reaction of hexamethylsilirane with water, alcohols, ammonia, amines, HCl and car?ylic acids and germanium and tin hydrides. More complicated ring opening reactions are observed with halogens, tetrahalomethanes and molecular oxygen. The oxidation and protolysis (H₂O, ROH, HCl, RCO₂H, NH₃, amines) reactions of hexamethylsilirane are exothermic at room temperature.     

Fluorine-containing Vinyl Ethers: I. Reactions with Carboxylic Acids

Polyfluoroalkyl vinyl ethers take up aliphatic and aromatic carboxylic acids in the presence of 0.2-5 wt% of trifluoroacetic acid at 55-105°C to give fluorine-containing hemiacetals in 60-100% yields.     

Organylthiochloroacetylenes: IX. Reactions with geminal and vicinal dithiols

Alkylthiochloroacetylenes react with geminal (in ether) and vicinal (in THF) dithiols to form, respectively, functional 1,3-dithiolenes (yield 43%) or 1,3-dithiolanes (yield 34%).