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The scope of the B(C 6 F 5 ) 3 -catalyzed hydrosilylation of (X)Ph-CH=O and (X)Ph-C(R)=O was expanded to include a large set of substitutents (X = H, , m-NO 2 , p-Et; R = Me or CF 3 ). Reactions proceed at room temperature with high chemoselectivity in a host of solvents (toluene, benzene, CCl 4 , 1,2-dichloroethane, and methylcyclohexane), or under solventless conditions, with hydrosilylation yields ranging from 85 to 95 % (for aldehydes) and 71 to 100 % (for ketones) and no noticeable solvent dependency of hydrosilylation yields. Replacing B(C 6 F 5 ) 3 for M(OTf) 3 (M = Bi, Al, Ga, Sc) causes a dramatic change in

The structures of a number of fluorocarbocations were calculated at the correlated MP2/6-31G* level. 13C and 19F NMR chemical shifts of fluorocarbocations were calculated for the first time using IGLO and GIAO-MP2 methods. The data showed good correlation of calculated 19F and 13C NMR chemical shifts with the experimental chemical shifts of fluorocarbocations. The correlation for GIAO-MP2-calculated 19F NMR chemical shifts with the experimental data is excellent. Using theoretical calculations as guidance, the protolytic cleavage of trifluoroacetic acid (CF3COOH) in superacids forming CF4 was also investigated experimentally and by ab initio calculations. This reaction is suggested to involve the gitonic CF3C(OH)(OH2)2+ dication as an intermediate.

Starting with appropriate alkylnaphthalenes , 3,10-dimethyl-2, 3,10-diethyl-3, 2,3,10,11-tetramethyl-4 and 3,4,9,10-tetramethyl-perylene 5 were synthesized by a sequence of radical cation and radical anion coupling steps. Persistent oxidation dications of parent perylene 1, alkylperylenes 2-5 and dibenzo[cd,lm]perylene 6 were generated in SbF 5 -SO 2 ClF. Based on 1D-and 2D-NMR experiments combined with AMl calculations the charge delocalization mode in the dications was deduced. The total deshielding ( 13 C), substituent effects, conformational/ geometrical changes and tropicity in the dications are examined.Whereas alkylperylene dications represent 18 electron Hückel dictations with a diamagnetic ring current (more diatropic than their neutral precursors), the 24 (20 periphery) dication of dibenzoperylene exhibits a paramagnetic ring current which greatly shields its protons (more paratropic than neutral hydrocarbon).

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Die Alkylierung der niedrigkettigen Alkane (III) mit dem aus Ethylen (I)/HF‐TaF5 intermediär erzeugten Ethylkation (II) zu den Ethylalkanen (IV) wird untersucht.

Cyanation and Nitration of Toluene with Cyanamide and Nitramide through Intermediate Cyano-and Nitrodiazonium Ions. Attempted Fluorination of Aromatics with Fluorodiazonium Ton1 Summary: Toluene is cyanated and nitrated with cyanoand nitrodiazonium ion, generated via in situ diazotization of cyanamide and nitramide, respectively, with NO+BF4~. Attempted fluorination with fluorodiazonium ion, prepared from cis-difluorodiazene and arsenic pentafluoride, gave only trace amounts of fluoroaromatics.