Cyano complexes boron

Cyano compounds liquid crystals, 12, 278 in silver(III) complexes, 2, 241 Cyanocuprates, with copper, 2, 186 Cyano derivatives, a-arylation, 1, 361 Cyanosilanes, applications, 9, 322 Cyclic acetals, and Grignard reagent reactivity, 9, 53 Cyclic alkenes, asymmetric hydrosilylation, 10, 830 Cyclic alkynes, strained, with platinum, 8, 644 Cyclic allyl boronates, preparation, 9, 196 Cyclic allylic esters, alkylation, 11, 91 Cyclic amides, ring-opening polymerization, via lanthanide catalysis, 4, 145... 

However, these conditions have not been applied to other epoxides. Catalysis by the boron trifluoride -diethyl ether complex is very useful for the ring opening of cyano-substituted epoxides " and glycidic esters see the formation of and Table 14. This is demonstrated by the regioselective opening of the epoxide ring in 2,3-dimethyloxirane-2-carbonitrile to provide 3-fluoro-2-hydroxy-2.3-dimcthylbutanonitrile... 

Diethyl phosphorocyanidate adds to a,/J-unsaturated aldehydes or ketones in the presence of lithium cyanide in a 1,2-fashion28. Boron trifluoride-diethyl ether complex catalyzed rearrangement of these allylic phosphates shows high E selectivity (>85 15) for the adducts derived from aldehydes and Z selectivity (>90 10) for ketone adducts. The selectivity of the rearrangement can be explained by assuming a chairlike transition state, in which the sterically more demanding x-substituent occupies the quasi-equatorial position. The steric requirement decreases in the order of R1 > CN > H. Thus, the cyano substituent occupies the quasi-equatorial position in the aldehyde-derived adduct (R1 = H), but the quasi-axial position in the ketone-derived adduct (R1 = CH3, C6H5). 

Adducts of cyclic enones (n = 1, 2 R = H or CH3) and diethyl phosphorocyanidate rearrange in a suprafacial fashion to give (3-cyano-2-cycloalkenyl) diethyl phosphates 1 under boron trifluoride-diethyl ether complex catalysis26,27. 

Cyano(trimehyl)silane (TMSCN) serves as a cyanating agent for carbonyl groups in the presence of a catalytic or stoichiometric amount of a Lewis acid such as boron trifluoride, titanium(IV) chloride, tin(IV) chloride, etc. Thereby, a wide variety of chiral ligands was designed and used for asymmetric cyanation reactions. Among them, titanium complexes have mostly been employed as the catalysts. 

A group of Russian workers [22 to 27] reported on the fluorination of mixtures of solid amines, amides, or cyano compounds with KF or CaF2. The reactions were carried out in a stream of F2 diluted with N2 at about -10 to +10°C. NF3 was one of the main products and was accompanied by fluorinated fragments of the compounds treated. The N-containing compounds studied include aliphatic amine hydrochlorides [22, 23], the amides of trifluoro- and difluoro acetic acid [24], potassium cyanate [25], silver and potassium thiocyanate [26], and a acetonitrile boron trifluoride complex [27]. 

A study has appeared which describes the preparation and properties of hydrolytically stable cyanohydro(pyrrolyl-l)borates and chiral boron-containing amine-cyano(pyrrolyl-l)borane complexes. Finally, two reports have appeared concerning the preparation, thermal stability, and stereochemistry of silyl-substituted aminoboranes. ... 

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