Boronic first preparation

Nitronium tetrafluoroborate was first prepared by adding a mixture of anhydrous hydrofluoric acid and boron trifluoride to a solution of dinitrogen pentoxide in nitromethane. Nitric acid can be used in place of dinitrogen pentoxide, and by replacing boron trifluoride by other Lewis-acid fluorides Olah and his co-workers prepared an extensive series of stable nitronium salts. ... 

Whether or not such electrophilic organometallic species can be identified, or indeed isolated, depends primarily on the stability of the counteranion. The per-fluorophenyl boron compounds B(C,sF5)3 and [B(C6F5)4] , first prepared by Stone and co-workers in 1963 [33], proved particularly useful in this respect. Their use in metallocene polymerisation catalysis [34, 35] led to significantly more active catalysts and well-defined catalyst systems that proved mechanistically informative. These results have then enabled similar species to be detected in the more complex MAO-activated catalyst systems (vide infra). 

Linear polyethylene can further also be considered as polymethylene. Althoguh first prepared by the thermal decomposition of diazomethane,243 244 Meerwein should be credited to have prepared it by catalytic polymerization of diazomethane effected by boron compounds (esters, halides, alkyls)245-247 taking place with concomitant dediazotation ... 

Benzo-1,3-ditellurolylium tetrafluoroborate 76 turned out to be the first preparatively isolated salt of a heterocyclic carbocation containing two tellurium atoms in a ring (91UP3). The synthesis of 76 was carried out, similar to its sulfur analog benzo- 1,3-dithiolylium boron tetrafluoride (76BCJ3567), by treatment of a solution of 2-butoxybenzo-l,3-ditellurole in acetic anhydride with 2 equivalents of HBF4. 

Historically, C-borylated pyrazoles were first described in 1962. A few years later, N-borylated species containing four-coordinate boron were prepared, i.e., the poly(l-pyrazolyl)borate anions and the (neutral) dimeric pyrazol-l-ylboranes = pyrazaboles. The first monomeric pyrazol-l-ylborane containing trigonal boron was reported in 1980. In addition, several cationic species in which two or more boron atoms or a boron and a carbon atom are bridged by pyrazolyl groups are known, but their chemistry has not yet been explored at all. 

The name is derived from the Latin Scandia, the name of Scandinavia. Mendeleev predicted the existence of the element as eka-boron. It was discovered by Lars Fredrick Nilson (1840-1899) in 1878 when he was investigating trace elements in euxenite and gadolinite. Metallic scandium was first prepared in 1937. Spectroscopic analysis has shown that scandium is present in the sun and other stars. Blue beryl may be colored because of scandium. The silvery metallic element is used in high-intensity lighting. 

Kiyooka and coworkers have reported a boron catalyst prepared from BHj-THF and N-p-toluenesulfonyl-L-valine [111]. These boron complexes were first reported as stoichiometric reagents which promote the Mukaiyama aldol addition reaction. The outcome of the addition reaction exhibits a dramatic dependence... 

Amine-boranes are important boron-nitrogen compounds. They are prepared by various methods such as direct combination of amine and diborane,1,2 reaction of tetrahydroborates with ammonium salts,3 transamination of amine-boranes,4 or displacement of tetrahydrofuran from tetrahydrofuran-borane which is first prepared from boron trifluoride etherate and sodium tetrahydroborate,5 or by less convenient methods like reduction of an appropriate... 

Porous glasses were first prepared and described by Grebenshchikov and co-workers (State Optical Institute, Leningrad) (89, 90). This research was continued by Zhdanov and co-workers (85-87). Usually, porous glasses are prepared by treating sodium-boron silicate glasses with inorganic acids. 

Boron carbide was first prepared by Joly [156] and labeled as BgC by Moisson [157]. In 1934, Ridgeway [158] suggested the composition B4C, which is still under controversial discussion. As discussed in Section 7.2.2.2 in connection with the crystal structure, the composition as assessed today ranges from B4 3C to B10.4C. Due to the fabrication process where carbon is used to reduce boron oxide, the composition of the commercially available boron carbide is close to B4C. 

The name silicon was proposed by Thomson, since the element is non-metallic and resembles carbon and boron. Berzelius called it silicium or Kiesel. He first prepared pure boron chloride (chlorbundet boron) and analysed it (boron 9 257, chlorine 90743). It was discovered independently by Dumas when his paper was published, Despretz produced evidence that he had discovered it in July 1823, Thomson regarded Despretz, Berzelius,... 

Boron tris (trifluoromethanesulfonate) was first prepared by Engelbrecht and Tschager in trifluoromethanesulfonic acid solution vide infra) as a conjugate acid system. Olah and co-workers have isolated B(OS02CF3)3 in pure form by treating boron trihalides (chlorides, bromides) with 3 equiv of triflic acid in Freon 113 or SO2CIF solution. 

Fischer first prepared carbyne complexes by the action of boron halides on carbene compounds of chromium, molybdenum, and tungsten. 

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